“Free radicals” are a special type of atom that have been linked to many age-related diseases. They form as a result of a process called Oxidative Stress, which takes place when an oxygen molecule splits into single atoms with unpaired electrons. The nature of electrons is such that they like to be in pairs and as a result will “freely” and “radically” search throughout the body for another electron to pair with. They could almost be considered romantic if they were not so dangerous!

Their main danger comes from the damage that they cause to cells or cell membrane, proteins, and DNA. Cellular damage occurs when free radicals travel through cells and disrupt the structures of other molecules. The gradual accumulation of them, and the increased damage that builds as more and more of them collect, is what helps cause many of the aforementioned aging diseases. Our body is under constant assault from oxidative stress, and cells may function poorly or die if it occurs too frequently and without proper bodily maintenance.

Free radicals are a waste byproduct that form as a result of various chemical reactions that take place during our bodies’ normal metabolic processes. They are then “dumped,” and their eventual buildup will often harm our bodies much like how factory waste harms the environment However, they are not entirely useless; it is impossible for our bodies to turn air and food into chemical energy without a chain reaction of free radicals. Free radicals are also a critical part of the immune system, as they additionally move through our veins and can confront foreign invaders [1].

What are free radicals?

Understanding free radicals necessitates an elementary knowledge of chemistry.

Electrons orbit around atoms in levels called shells. Each shell is filled by a fixed number of electrons, and when the first shell is full then electrons will start to fill the next shell.

If there is an atom whose outer shell is not full then it may bond with another atom by using the electrons to fill its outer shell. These types of atoms are known as free radicals.

Atoms that have a full outer shell become stable, however free radicals are unstable. They are “desperate” to acquire the full number of electrons that are necessary to fill all of their shells and will therefore react quickly with other substances.

Take the example of oxygen molecules. If they split into single atoms that have unpaired electrons then they too will become unstable free radicals that seek other atoms or molecules to bond to. If this procedure continually occurs, then it will begin a process called oxidative stress.

Smoking, UV rays, air pollution, fast food, pesticides, ionizing radiation, drugs, and inflammation have all been linked to the formation of free radicals. We must be diligent when it comes to understanding how these influences can affect our bodily health, and then fight back with natural antioxidants.

Free radicals are heavily linked to aging

One of the effects of oxidative stress is that it can damage our body’s cells and thus promote many of the diseases and symptoms related to aging, such as wrinkles and gray hair. They will take electrons from other atoms in order to become more stable, a process that may cause diseases or signs of aging [2].              

In 1956, the “Free Radical Theory of Aging” was outlined as a way to understand how exactly our bodies age over time. Everybody ages, and as we age our body loses its ability to fight the effects of free radicals. Over time our bodies produce more free radicals and more oxidative stress, which increases the rate at which cells are damaged and thus can bring about degenerative processes.

Many age-related diseases such as muscular degeneration, certain cancers, atherosclerosis, cardiovascular disease, emphysema, Alzheimer’s disease, Parkinson’s disease, ulcers and all inflammatory diseases such as arthritis and lupus, and many others are linked to free radicals. Free radicals can be found in the food we eat such as fried foods, the medicines we take, the air we breathe, and the water we drink. Free radicals are also found in alcohol, tobacco smoke, pesticides, and air pollutants.

Several studies and theories have been linked to oxidative stress and the buildup of free radicals including: [3]

• Genetic degenerative diseases, such as Huntington’s disease or Parkinson’s
• Age-related changes in appearance, such as loss of skin elasticity, wrinkles, graying hair, hair loss, and changes in hair texture
• Cataracts and age-related vision decline
• Diabetes
• Cancer, which is associated with chromosomal effects and oncogene activation due to the reaction of free radicals [2]
• Central nervous system diseases, such as Alzheimer’s and various forms of dementia
• Cardiovascular diseases due to clogged arteries
• Autoimmune and inflammatory disorders, such as rheumatoid arthritis and cancer

The free radical theory of aging is comparatively new; however, several studies boost its credibility. Researchers focused on cell’s mitochondria, the “powerhouse” that process nutrients to power the entire cell. Experiments on rats, for example, showed a noteworthy increase in free radicals as the rats aged. These alterations coincided with age-related declines in their health. These experiments also showed that free radicals produced in the mitochondria harm the substances that the cells need in order to work properly. This damage causes mutations that produce more free radicals, thus accelerating the process of damage to the cell. This helps explain aging since aging quickens over time. The gradual, but increasingly rapid buildup of free radicals, offers one explanation for why even healthy bodies age and depreciate over time [2].

Antioxidants can stave off free radicals

Antioxidants, molecules that prevent other molecules from oxidizing and thus undergoing oxidative stress, can help to avert the harmful effects of free radicals. They can also decrease or even nullify the effects of free radicals, as they can provide an electron to free radicals and thereby reduce their reactivity. The uniqueness of antioxidants is that they can donate an electron without becoming reactive free radicals themselves.

There is no single antioxidant that can combat the effects of every free radical. Free radicals have different effects in different areas of the body, and every antioxidant performs differently due to its chemical properties. Antioxidants such as vitamins C and E, beta-carotene, glutathione, and plant estrogens called phytoestrogens all scavenge the body and help remove free radicals. Honey can also function similar to antioxidants by removing free radicals. Additionally, selenium, a trace metal that is required for proper function of one of the body’s antioxidant enzyme systems, is sometimes included in this category. The body cannot manufacture these micronutrients so they must be supplied in the diet.

Foods that are rich in antioxidants include citrus fruits such as oranges and limes, berries, and many other fruits that are rich in vitamin C. Carrots are known for their high beta-carotene content, while the soy in soybeans, and some meat substitutes, are high in phytoestrogens. Apricots, spinach, mangoes, pumpkins, broccoli, and eggplants are all also helpful, along with a plethora of other fruits and vegetables [4].

More research needed

A 2010 study on antioxidant supplementation for the prevention of prostate cancer found no benefits. Furthermore, a 2012 study found that antioxidants did not lower the risk of lung cancer. On the other hand, the study found that people who were already at a heightened risk of cancer, such as smokers, actually had a slightly elevated risk of cancer due to antioxidants.

Some investigators have found that supplementation with antioxidants is injurious when people take more than the recommended daily allowance (RDA). A recent analysis found that high doses of beta-carotene, or vitamin E, appreciably increased the risk of dying. One study found that long-term use of beta-carotene could reasonably reduce the risk of age-related mental problems [4]. But perhaps one of the most important discoveries is that antioxidants are unable to “cure” the effects of free radicals completely [5].  

Additionally, we do not yet fully understand why free radicals form in the first place. They may result as an early sign of cells fighting diseases, or that free radical formation is simply a natural expectation that comes with aging. It is not possible to understand them completely without more conclusive research, which should be encouraged considering the significant impacts that free radicals can have upon our bodies.

References

1. https://www.rice.edu/~jenky/sports/antiox.html
2. https://www.medicalnewstoday.com/articles/318652#How-do-free-radicals-damage-the-body
3. http://www.mytruehealth.info/mytruehealth_antioxidants_freeradicals.html
4. https://www.medicalnewstoday.com/articles/318652#Antioxidants-and-free-radicals
5. https://www.medicalnewstoday.com/articles/318652#What-we-do-not-know

Enveloping our body like a piece of clothing, our skin is a miraculous organ that both forms a barrier against potential invaders and plays a crucial role in the maintenance of vital functions. It is a mirror that reflects our experiences, memories, and fate with the lines and marks on it. With a surface area of 1.72 square meters and a weight of approximately 9.6 kg, including the fatty tissue under it, the skin is the largest organ in our body and life cannot possibly be maintained without it.[1] It is through the skin that we learn knives cut, fire burns, and our mother has very soft hands. We don’t even realize, but the skin quietly carries out other numerous functions such as sweating toxins out of the body, maintaining body temperature, and synthesizing vitamin D.[2] Some of these functions are related to the sun and the protection of our body from it.

The sun emits all kinds of rays across the electromagnetic spectrum. The lethal ones among these rays are filtered by the atmosphere that envelops the Earth, so very few of these dangerous rays reach the land.[3] The rays that reach Earth are visible (wavelengths of 400-700 nm) and ultraviolet (wavelengths of 100-400 nm) rays. Ultraviolet radiation comes in three types: UVA, UVB, and UVC.

Having wavelengths of 320-400 nm, UVA rays make up 90% of the UV that reaches Earth’s surface. Regardless of whether it is cloudy or sunny, the same amount of these rays reaches Earth and penetrates as far as the lower layers of the human skin. UVA rays damage the connective tissue under the skin, causing the skin to get old and the formation of free radicals, which indirectly cause DNA damage, hence terminal skin cancers or melanoma. Rays that come in these wavelengths are also largely responsible for allergic reactions on the skin.

With wavelengths of 280-320 nm, UVB rays make up 5-10% of the UV radiation reaching Earth. These rays help with the synthesis of vitamin D but also cause sunburns and the synthesis of melanin in the skin. UVB rays also have a role in mutating genes that prevent growth of tumors, thus leading to the development of skin cancers other than melanoma.

With wavelengths of 100-280 nm, UVC rays are harmful to living things. When they reach the Earth’s atmosphere, UVC rays interact with the oxygen atoms here. This interaction leads to the formation of the ozone layer, which prevents UVC rays from almost never reaching the ground. These dangerous waves have been put into humankind’s service by being employed in the creation of the protective ozone layer.

Ultraviolet rays and the harmful effects of visible light on the skin

There are short-term and long-term effects of UV rays on the skin.

The short-term effects are sunburn, heat stroke, allergic reactions, suntan, and viral diseases such as herpes, which are usually felt shortly after exposure to the sun and can be triggered by suppression of the immune system. The long-term, accumulative effects are photo-aging (the skin getting wrinkly due to solar rays), sunspots, cataracts, and the development of skin cancers.[4]

On the other hand, our skin is not entirely unprotected against the dangerous effects of the sun. The keratin layer in the epidermis, the uppermost layer of the skin, absorbs or disperses light, so the amount of light penetrating into the layers below is significantly lowered. Beta-carotene in the skin along with some enzyme systems reduce free oxygen radicals released after exposure to the sun and thus eliminate solar damage. Likewise, melanin, which gives our skin its color, lies above the nuclei in skin cells and acts as an umbrella that protects the cellular DNA from solar radiation.[5]

Six subgroups of skin types have been determined according to color of the hair, eyes, and skin, as well as the skin’s reaction to solar rays. This classification is widely accepted for identifying risk groups and determining specific protection measures.[6]

Although the number of melanosomes, or melanin-producing cells in the human skin, is the same in all humans, the color of the skin is determined by the genetic differences in the type, amount, and size of melanin pigments. Melonosomes in Europeans are small and light, while those of Africans are larger and darker.[7]

The importance of protection from the sun

The frequency of skin cancer has been increasing, which is precipitated by the fact that the ozone layer has gotten thinner and people are not well informed about UV protection. Many people take beach vacations and sunbathe, do mountain sports, have tanned skin, work in open air professions (such as construction workers, lifeguards, and tour guides), and they do so without much care.

For protection, we should first know that harmful effects of solar rays accumulate over time. The damage caused by the sun is stored in the body, just like change we save in a piggy bank. Unfortunately, we accumulate 40-50% of the total damage we are exposed to in a lifetime in the first quarter of life – that is, during childhood and our teenage years.[8] The skin’s natural protection mechanisms are not fully developed during these periods, nor is our understanding of protection. A research study carried out in Australia has shown that the rate of malign melanoma seen in young people can be reduced by 73% through effective solar protection methods.[9]

The major reason for wrinkles, the primary and fundamental indication of aging skin, is not in fact our age but the sun. UVA and UVB rays break down the connective tissue below the skin, disrupt the skin’s repair mechanisms, and cause skin aging (or photo-aging). Therefore, photo-aging takes place faster and earlier in people who work outside.[10]

{Picture: Photo-aging visible on one side of a truck driver’s face}[11] 

It’s imperative that we begin teaching children and adolescents about UV protection: having suffered five sunburns in childhood and early youth increases the risk of developing melanoma by 80%.[12] Children shouldn’t spend long hours in the midday, summer sun. 

Solar damage isn’t just more likely in children and teenagers, but also in people with skin type 1 or 2 (light skin), red hair, and/or colored eyes (blue); people, especially light-skinned people, with many skin moles; people whose family members have or had skin cancer; those who have a skin disorder triggered by the sun (lupus, dermatomyositis, rosacea); and people who have innate light sensitivity (albino, xeroderma pigmentosum, etc.). All these groups must be particularly careful about protecting themselves from the sun.

What are some ways to protect ourselves from UV Rays? Well, because UV radiation bombards the Earth most intensely at noon during the summer, staying indoors is greatly recommended between the hours of 10:00 am and 4:00 pm.  Additionally, the reflection rate of solar rays is higher by the seaside and in snowy environments.[13]

Wearing appropriate clothes is still the most effective and the least expensive method of sun protection. Clothing can have a solar protection factor (SPF) of 15-30. The level of protection is determined by the type of fabric, number of pores, and type, color, and thickness of weaving. The best clothes are made from cotton, silk, and denim and are unbleached and woven tightly. Wet clothes are more permeable. The use of wide hats, sunglasses, and umbrellas are also important for protection.

In addition to these measures, sun protection creams should also be used. The idea that protection creams will prevent the synthesis of vitamin D, voiced frequently lately, should not prevent the use of sun protection because the solar rays we receive during the day from the face and hands are sufficient for the synthesis of vitamin D. A person should pick a sun cream appropriate for their skin and apply it in sufficient amounts 20 minutes before going out. Babies should be protected through natural means, and physical sun protection should be used for children and pregnant women. A person should reapply sun protection products every two or three hours while outside, and, if planning to swim, they should choose water resistant products.

Besides physical protection that blocks, scatters, or reflects solar rays, there are also skin-absorbable chemical protections with cosmetically accepted formulations that eliminate light by absorbing it.

Generally speaking, a good sun protection should protect against both UVA and UVB rays. It should be cosmetically acceptable, non-toxic, water and perspiration resistant, and at the appropriate SPF (sun protection factor) level. However, because reapplication is required every two to three hours, protection above SPF 50 is the same. Therefore, it is no use buying a more expensive, higher protection product.[14] For people with type 3 skin (darker white skin with gold tone), SPF 30 is sufficient. For light skinned people, children, and pregnant women, however, SPF 50 is recommended.

SPF is the number indicating by how many more times a sunscreen protects the skin against UVB than the skin itself. Skin type is very important in sunscreen choice. The natural protection period of a person with type 1 skin is 5-10 minutes, while it may go up to 90 minutes for a person with type 6 skin. In other words, a light-skinned person gets a sunburn in 5-10 minutes of exposure, while a dark-skinned person may not get one at all. Therefore, these people should not choose products at the same SPF level. For example, if the skin’s self-protection duration is five minutes, a sunscreen with a SPF of 30 provides the same protection for 150 minutes.

Apart from sun protection creams, oral products can also help with sun protection. For example, oral zinc intake is proven to prevent cellular and DNA damage caused by UV radiation. Vitamin C is effective at preventing UVA rays due to its antioxidant properties and vitamin E at preventing UVB rays. In addition, the intake of beta carotene (a precursor of vitamin A) and bioflavonoids (also called vitamin P which generally has effects similar to vitamin C), found in orange and red fruit, protects against UV damage. Polyphenolic compounds in green tea also display protective properties against UV radiation.[15]

Finally, we should remember that using a sun protection product is a small part of our attitude toward your overall protection from the sun. Considering the role of the ozone layer in filtering the sun’s harmful rays, we should protect the perfect balance in the universe and re-evaluate our responsibilities and future actions for the maintenance of this balance.

Notes

[1] livescience.com.

[2] Gilchrest BA. “Sun exposure and vitamin D sufficiency,” Am. J Clin Nutr. August 2008, Vol. 88 # 2 570S-577S.

[3] Understanding UVA and UVB. skincancer.org.

[4] sciencelearn.org.nz.

[5] “The Protective Role of Melanin against UV Damage in Human Skin.” Photochem Photobiol. 2008; 84(3):539-549.

[6] laserdocs.co.uk/easy-way-to-find-out-your-fitzpatrick-skin-type/

[7] Ibid.

[8] Adele CG, Sarah C Wallingford and Penelope M. “Childhood exposure to UV radiation and harmful skin effects: Epidemiological evidence.” Prog Biophys Mol Biol. December 2011, 107(3): 349-355.

[9] Green AC, Williams GC, Logan V, Srutton GM. “Reduced Melanoma after Regular Sunscreen Use: Randomized Trial Follow-Up,” Journal of Clinically Oncology. 20 January 2011, Vol. 29 # 3:257-263.

[10] Fitzpatrick’s Dermatology in General Medicine.

[11] www.nejm.org/doi/full/10.1056/NEJMicm1104059.

[12] Markovic SN, Erickson LA, Rao RD, et al. “Malignant Melanoma in the 21^st Century, part 1: Epidemiology, risk factors screening, prevention and diagnosis.” Mayo Clin Proc, 2007; 82: 364-380.

[13] Skin cancer prevention and early detection. www.skincancer.org.

[14] www.dermnetz.org.

[15] Halliwell B. “Free radicals, antioxidants and human disease.” Lancet 1994; 344-:721-724.

We are all aware of the fact that there is certain rhythm and order in the movement of the sun and the earth, as well as other planets along their pre-assigned orbits. This order has ongoing without a glitch for possibly billions of years. The day and the night become longer and shorter on a schedule, and this is how we can develop calendars by calculating seasons, months, and days.

The movements of celestial bodies impact in multiple ways the biosphere in which we live. Trees shed leaves or bloom, some animals hibernate, and others enter reproduction season.

Time advances not linearly but in cycles. The internal systems by which the metabolisms of living things are organized are made to work according to numerous biological clocks that depend on the cyclical nature of time. These biological clocks are sometimes based on the length of a day and sometimes on long cyclical patterns that may span years. Periods of sunspots followed by explosions on the surface of the sun, for example, cause the reproduction cycles of populations of lynx and hare to peak every 11 years. This cycle is also tied to an increase in the production of wheat and certain species of fish breeding in abundance. The internal clock of the human metabolism is likewise organized during the day.

Scientists have long since noticed and started to research the different reactions of the human body to different time intervals throughout the day. It was realized that pains eased during certain times of day and intensified during others. There are also rising and falling cycles for hormones and the nervous system. These coincided with periods of hunger, meals, and sleep.

It has been found that certain changes occur in the physical and mental makeup of humans during the year, seasons, month and day. Researchers agree that every human has a unique physical and mental clock, but there are generally broad similarities. The scientific field researching these is called chronobiology. Researchers in chronobiology have demonstrated that certain changes occur, according to time periods, in the endocrine and autonomic nervous system as well as the body’s water and salt balance.

Other studies have focused on biological changes with respect to space. The regulation of the body’s biological rhythm is found to be influenced by the movements and positions of the earth on its own axis, the moon around the earth, and the earth around the sun. As the atmospheric environment changes, so do living things.

Towards the end of the 1960s, scientists found that a synthetic corticosteroid drug called methylprednisolone was more reliable for treatment of arthritis and asthma when taken in the morning rather than at other times. “These rhythms might affect responses to cancer treatment,” says Eric Holland, a neurosurgeon at Fred Hutchinson Cancer Research Center, adding that there are optimal times for administrating radiation in mice.

A forty-three-year-old patient with 27 tumors in her liver whose drug treatment for colon cancer did not work volunteered for a trial and recovered from cancer after rescheduling the administration of her drugs. Oncologist Francis Lévi was so amazed by this effect on the patient that he became a supporter of chronotherapy, or time-cycled treatment. To Lévi, who works at Warwick Medical School in the United Kingdom, timing can prove even more important than dose. In the trial, the patient was first wired up to a device like a clock so that metabolic rhythms could be better monitored. The patient had extremely regular sleep-wake cycles, which Dr. Lévi believed was likely to have contributed to the success of the treatment. This novel understanding did not spread before because researchers could not explain molecular foundations of daily rhythms, or circadian cycles, until 10 years ago, and clinical data was inconsistent.

Lévi and his team randomly divided 186 chemotherapy patients into two groups. They administered medicine to one group in accordance with the participants’ biological clocks and to the other group according to the standard procedure. More than 50% of the former responded well, whereas the rate remained at only 29% for the latter. Another study found that 298 patients who had heart operations in the morning were twice as likely to have unsuccessful operations and develop complications as compared to 298 patients who had operations in the afternoon. To prevent the effects of the surgeon’s selection of patients, the same surgeons operated both in the morning and in the afternoon.

The 2017 Nobel Prize for the field of physiology was awarded to three American biologists, Jeffrey C. Hall, Michael Rosbash, and Michael W. Young, for their study into biological rhythms. Their research presents remarkable insights into the reasons why the biological rhythms of plants, animals and humans are created in coordination with the movements of the earth. The researchers used the fruit fly, an exemplary organism, and found the genes that controlled its daily biological rhythm. Discovering that these genes initiate the secretion of a protein that accumulated overnight and dwindled during the day, the researchers revealed that these proteins caused a mechanism made to work in a certain rhythm when the time was right. It was like a watch had been set inside the fruit flies’ cell.

It is estimated that approximately 80% of our genes follow night and day rhythms (and also possibly seasonal rhythms). Indeed, it has been identified that fits of asthma and epileptic seizures develop according to certain daily rhythms. The products expressed by the genes that are active in most tissues peak early in the day and in the afternoon and reach lows after dinner and before bedtime. All these activities are carried out by the “molecular biological watches” written in our genes. If we can better understand our internal clocks, researchers believe they could discover breakthroughs in the treatment of up to 150 diseases, including cancer.

The time machine

Many tissues in the body have their own time schedules arranged by regular cycles in which numerous innate “clock genes” envelop the body like a net. The timing of all these clocks can have a powerful impact on metabolic activity, the increase in the number of immune cells, and many other things. “The best advice I can offer is don’t mess with your body clock,” says Professor Derk-Jan Dijk, director of the Surrey Sleep Research Center in the city of Guildford, England. [1]

The biological clock is an extraordinary system. A group of neurons in the hypothalamus in the brain, called the suprachiasmatic nucleus, are assigned as the central clock for all these activities in the body. The signals from this region play a role in initiating and finalizing the activities of the genes, which channel drugs to their molecular targets and help produce enzymes that destroy drugs. “Clock” genes are found virtually in every organ and tissue, and they are particularly important during cancer treatments, because interventions performed during such critical processes as the cycle of cellular division and growth and repair of DNA damage become significant for killing cancerous cells.

Cisplatin, an effective drug used for almost 50% of solid tissue cancers, kills malignant cells by binding to their certain parts, yet because the drug is toxic to the kidneys, lungs, and nervous system, efforts have been made to develop less toxic versions. Just as a cell develops cancer due to DNA damage, so is the destruction of the cancerous cell started by damaging the cell’s DNA. For this reason, some drug trials focus on blocking the DNA repair of the cancerous cell.

Observations made on the appearance and repair of DNA damage showed, as expected, that DNA damage was repaired more easily during certain periods of the day, leading to the hope that cancer can be treated through DNA repair if drugs are administered in tandem with this cycle. If optimal periods could be established for numerous normal cells to repair their DNA damage, administration of drugs can both optimize the useful effects of drugs and minimize toxicity of drugs with toxic properties.

The human organism and cells are not static, but dynamic. The behavior of our cells changes dramatically before and after a meal. Similarly, the movement and frequency of numerous materials circulated in our body when we are sleeping are different from when we are awake. Therefore, if the amount of a material doubles after lunch followed by a cup of coffee and if the material negates a drug taken by a patient, then that drug can be administered when this material is at its lowest in the body. For example, if the material is at a minimum at two in the morning, the drug can be given at that time, ensuring that the effect is maximized.

The studies into “man, the unknown” are bound to lead to many more discoveries about both treatments of diseases and the knowledge, power, and wisdom waiting to be found in the creation.

Note

1. https://woolcock.org.au/new-2/why-you-shouldnt-mess-with-your-body-clock-expert

References

• Leder, K., Pitter, K., LaPlant, Q. (2014). Mathematical Modeling of PDGF-Driven Glioblastoma Reveals Optimized Radiation Dosing Schedules. Cell. Cilt 156, Sayı 3, s. 603-616.
• Lévi, F., Zidani, R. & Misset, J.-L. (1997): Randomized multicentre trial of chronotherapy with oxaliplatin, fluorouracil, and folinic acid in metastatic colorectal cancer. Lancet 350, 681–686.
• Peeples , L. (2018). Medicine’s secret ingredient — it’s in the timing. Synchronizing drug delivery with a patient’s body clock can yield clear benefits. But will the data be enough to overcome long-standing hurdles? Nature 556, 290-292 (2018).
• “Why You Shouldn’t Mess with Your Body Clock: Expert,” woolcock.org.au. August 7, 2018.

Radiation, which refers to emissions of light or particles, is a type of energy transfer. Radiation takes place at any given moment in the environment or the body. Among sources of radiation to which humans are exposed daily are sun rays, radio waves coming from devices such as mobile phones and TV sets, appliances such as ovens or irons that emit heat, and medical machines such as ultrasounds. The radiation emitted from devices and machines do not cause ionization. Ionizing radiation is made up of high-energy wavelengths or particles, and this is the kind of radiation we get from x-ray, CT, and nuclear imaging. This is used to penetrate tissue to reveal the body’s internal organs and structures. Ionizing radiation can damage DNA, and when our cells cannot fully repair the damage, this may result in DNA mutations.[1] The radiation which poses real danger to humans and has the power to ionize is when radioactive—or unstable—atoms decay and emit alpha (α), beta (β), and gamma (γ) rays.

The earth, air, water, and all living things are more or less radioactive because radioactive atoms are everywhere. The average person is annually exposed to radiation levels of 2.6 – 10 mSv (millisievert), which is not that alarming. The maximum limit recommended for people exposed to radiation for occupational reasons is 100 mSv. The lungs of a person who smokes one pack of cigarettes a day are exposed to an annual radiation of 106 mSv.

How can we protect ourselves?

It is recommended by the World Health Organization that children younger than 16 should not use mobile phones; when they do, their calls should not exceed 10 minutes. When purchasing devices, you should also take into account its SAR (Specific Absorption Rate). Prefer devices with a SAR<1 W/kg. It is also recommended to unplug electrical devices when you are not using them, to keep electrical appliances as far away from your head as possible, use the hairdryer for short periods and in intervals, and to avoid using mobile phones for long conversations (or use headphones!).

It’s also worth reconsidering whether using radiation-emitting devices such as mammography, x-rays, or ultrasounds are absolutely necessary. In 2010, the British Department of Health and Social Care banned using tomography for screening purposes. Another study in the US found that one in ten people are exposed to high levels of radiation because of medical tests.

The average radiation rates (mSv) a person was exposed to during use of certain imaging devices is as follows:

Researchers also found that employees in nuclear power plants were exposed to amounts of radiation that far exceeded allowable amounts.

Beware of radon

The natural radiation humans are exposed to most is the gas radon. Some matter with radioactive atoms such as uranium and thorium – both present in the earth since its birth – emit radon, which seeps through the earth and into the walls of houses and through gaps in plumbing. It is recommended to air houses at least 15 minutes every 24 hours as the only way to be protected from radon.

The resistance of living things

Creatures have been created with different forms of resistance to the elements, including radiation. For example, dogs have a lower resistance than humans, while many other creatures such as rabbits, tortoises, and fruit flies have a higher resistance. And then there is the cockroach, which can survive even a nuclear attack. The lethal radiation dose for cockroaches is an incredible 670- 1000 Sv, whereas it is 6-8 Sv for humans.

Scorpions are also much more radiation-resistant than humans. They can withstand up to 1500 Sv, an amount that is 250 times the maximum dose humans can take. Studies have found a correlation between the strength of a scorpion’s venom and their resistance to radiation. The greater the amount of venom, the greater the resistance they have. The presence of the neural transmitter serotonin supports this view.

Are humans radioactive too?

Humans contain trace amounts of radioactive atoms, namely uranium (²³⁸U), potassium (⁴⁰K), and carbon (¹⁴C). An 80 kg human has natural radiation of 8000 becquerel every second, which is equal to 100Bq per kilogram. This amount is not high enough to cause any worry. The human body has 40 trillion cells on average, and every cell has about 100 trillion atoms. The proportion of the radiating atoms in the body is about 8000/4×10²¹.

Precision protection

The radioactive atoms in the body with the highest probability for carcinogenic effects are potassium (⁴⁰K) and carbon (¹⁴C) atoms. The decomposition that leads to cancer stems from mutations in genes, but the molecules that are the building blocks of genes do not have potassium atoms. The likelihood that a cell gets harmed is very low: it is necessary that the particles emitted from the radioactive potassium atom crash into the DNA molecule and harm it, which is as unlikely as threading a needle when blindfolded. The DNA is precisely protected inside the nucleus located at the center of the cell. If we consider the fact that the average diameter of a cell is about 10 microns (1 micron is one-thousandth of a millimeter), we can better appreciate how little space DNA occupies.

Radiocarbon atoms (¹⁴C), on the other hand, might be present in DNA molecules, and they are more dangerous because the emitted particles are more likely to find the target despite having weaker radioactive properties than potassium. A radioactive carbon atom turns into a nitrogen (¹⁴N) atom and may thus cause a chemical change in the DNA. In other words, the carbon atom is possibly to blame for the unexpected development of cancer.

The likelihood of harmful radioactive particles hitting a person’s DNA is low, and the protective system provided for it lowers the likelihood of developing cancer even more. New DNA molecules that form during DNA coupling are repeatedly checked by inspector enzymes. If there is an error, it is detected and then corrected. The broken code is taken out to be replaced with the correct version. Meanwhile, all these steps are checked by other enzymes assigned to the task. More errors might be made in the newly produced DNA molecule because of external factors. Yet ribosomes in the cell start to produce repair enzymes, as per the instructions from the DNA.

When thinking about all the protective factors that have been coded into the DNA for our survival against the 8000 radioactive activities that occur in our body every second, one cannot help but feel awe for the infinite mercy and wisdom that operate in our lives.

References

• http://time.com/5069317/california-mobile-phone-radiation/
• https://www.health.harvard.edu/cancer/radiation-risk-from-medical-imaging
• Choppin, G. et al., Radiochemistry and Nuclear Chemistry, Oxford: Elsevier Science & Technology, 1995.
• www.physics.isu.edu/radinf/natural.htm

[1] https://www.health.harvard.edu/cancer/radiation-risk-from-medical-imaging

What possible similarities could there exist between a human and a tree? Interestingly, the open wounds of human beings and trees are subject to the same laws and are healed in similar ways.

Have you ever wondered what kinds of similarities exist between human skin and the bark of a tree?

Trees are subject to major and minor injuries just like humans are. These injuries could be the result of a broken branch, insect infestation, animal damage, fire and human related damages. These kinds of injuries can lead to the infection of a plant which can cause rotting and damage to the transport tissues like phloem (nutrients) and xylem (water) by microorganisms and insects (bacteria, fungi, parasites).

Fluid excretion in wounds and development of scar tissue

Blood serum is secreted in human wounds, whereas gum and resin type fluids are secreted in various trees (Figure 2 and 3). Serum plays an important role in sterilization of the wound, along with blood coagulation. Defense mechanisms in trees involve excretion of different fluids (resin in needle-leaf trees, gum in broadleaf trees) that are synthesized via composition of various chemicals. The most important feature of these fluids is that with their special chemical make up, they can protect the wound from organisms like bacteria, fungi, and insects that are potentially harmful to the tree. These fluids also feature coagulation like the human serum; they congeal and solidify after excretion and trigger a biological healing process while physically covering the wounded area.

Wounds are repaired with new connective tissue cells (fibroblasts) in humans and by callus in trees. Healing of the wound following the coagulation takes place with proliferation of cells in this region (epithelialization). First, epithelial cells wrap the wound via proliferation. New transport tissue is developed during this process. Next, fibroblasts that are in charge of wound repair are transferred into coagulate via this transport tissue. Fibroblasts synthesize collagen protein of the required fiber structure needed for the wound repair. Injured area is woven with these, and recovers its former shape in time depending on the size of the wound.

Healing is granted through timely reproduction, transformation and maturation of paranchimatic cells that make up the callus, when only a portion of tree bark is damaged. Paranchimatic cells are fused side by side and they form a thick elevation of callus tissue around the wound (Figure 4). At the end, these are activated for the development of a new, healthy cambium and bark. Cambium tissue is responsible for vertical and lateral growth of a tree therefore it is vitally important that it does not suffer any damage. This tissue in growth season proceeds from the perimeter of the wound towards the center for a complete healing. The productive efficiency of the tree medium can speed up or slow down the curing process similar to humans.

The reality is that all living things are created with a dress suited for their environments so that their bodies can be protected from negative elements from the outside world. Organisms are armored from many harmful physical (mechanical, extreme temperatures, light etc.) and chemical effects with this perfectly bestowed dress as a manifestation of the divine compassion in the universe just as in the case of the wounds of humans, animals and plants which are subject to the similar laws found in nature.

These findings might help researchers to design more effective drugs for various human infections by focusing on the minimization of the inflammation. Moreover, bats are capable of sustained long flights, as some bat species can fly more than 1,000 km in a single night. With such intense physical activity, cells often produce high levels of toxic (free radicals) that would usually damage DNA sequence.

This study also found that bats are equipped with a highly functional set of genes that mediates DNA repair in response to DNA damage, thus bats are protected from toxic cellular waste with this advanced mechanism. Aging, cancer and infectious diseases are the three major issues medicine is facing today and biological abilities granted to bats seem to provide important clues for us to discover new ways to combat these big health problems

Adam forgot, so did his children.

How does our brain store information? How is it possible to make learning faster and easier? Is there any way not to forget what we have learned and to remember things more easily? Of what importance is the fact that information is never deleted from our memory, even if we have forgotten it? These are among many of the questions for which answers have been sought over the years.

Memory is one of the functions of the brain and it is defined as the ability to preserve acquired information consciously and relate it to the past. It is not just a certain portion of the brain, but rather the entire organ that functions in storing, processing, and retrieving external and internal signals. Signals that build up our memory are what we usually perceive through our five senses. When we burn our hand, or see or experience a traffic accident , when we are given a compliment and many other events are all examples of external signals, whereas internal signals are related to our nervous system or imagination. The pain one feels during a heart attack, the anxiety of a cold sweat, or a beautiful daydream are all stored in our memory too. We may or may not remember them. There is no deletion; it is simply that we do not remember. Forgetting is a state that is encoded in our makeup with differing degrees, depending on the kind of life the person has experienced. Age, gender, stress, habits, and illnesses all have varying roles in forgetting.

Short-term memory

Short-term memory refers to saving and remembering what we have learned a few seconds or minutes ago; the prefrontal brain is the location for this temporary processing. Signals are kept in this portion of the brain for a few seconds and then conveyed to the back stage (as in the transfer of data from the cache memory to the main memory in computers). We tend to quickly forget those things on which we have not spent a long time or to which we have not assigned great importance, even though we can understand them. Imagine how unbearable our life would be if we were to store in our memories and remember things in infinite detail like the color of the wall we are facing, the variety of the objects around us and their qualities, the air we breathe in and out, or every beat of our heart. The signals that come to our brain within a certain time frame are filtered according to our needs and their significance and limitations are applied depending on their qualities and quantities.

There is no consolidation processing for short term memory. Second or minutes after signals are received they are retrieved in accordance with what we need; if they are insignificant for us, they are forgotten in the same amount of time. The information that is significant for the person is consolidated in the hippocampus and reserved in mid and long-term memory units.

Mid and long term memory

After being processed in the sub-cortex (limbic system) of the brain, signals are saved. Depending on their level of urgency, the meaning they stand for, and their emotional effect, signals are saved in either the mid or long term memory. Pain, joy, pleasure, and fear are states that solidify memory traces. A heart attack, the infliction of wounds and bruises or humiliation, accidents, visits from a loved one-these are all examples of events that are easily remembered. However, a lasting record is almost impossible to attain if the subject is something that has been forced (like a student studying for higher marks) or if the subject does not appeal at all. Consolidation is necessary to make a short term memory a lasting one. However, if a student is curious about the subject and enjoys what he or she is learning, then long term memory is possible without too much effort in consolidation. Forced consolidation (e.g. a student’s orientation to attain higher marks) requires a longer period. The information is consolidated more easily when a person is in a sound and alert state of mind.

Storage in the long-term memory does not occur immediately after something has been learned or experienced. For this storage to be possible at least an hour needs to pass to synthesize the memory proteins that are responsible for recording. If electric shock is applied to a person’s brain immediately after an unforgettable event, they will not be able to remember the event. But if the electric shock is applied an hour later, the memory remains.

Once stored in long-term memory, information can be retrieved, even after months or years. When new information is obtained older information is called up and they are saved with a new pattern of storage, with the newcomers being related with the ones that have already been stored; it is in this way that long term memory is generated.

It has been argued that RNA has a role in storing old information. In experiments, guinea pigs were taught information through repeated practice which is stored in their long term memory. The brains of these animals were later minced up and fed to other animals. It was observed that those animals which had been fed the brains learned faster and more easily than other animals that had been fed on a diet that did not include the brains. This shows us that information encoded in the memory is not lost; rather it is transferred with the help of certain molecules. It is also known that DNA is related to genetic memory.

It has been found that people with good memories have a greater number of nerve cells and channels of transfer in the memory-related zones of their brains (cortex, corpus callosum, hippocampus, thalamus, hypothalamus, limbic system, amygdale, temporal lobe, and prefrontal cortex), while there are less cells in other zones of the brain. Nerve cells are stimulated while signals are stored in one’s memory. Even if a person has a weak memory, activities like reading, memorization, or other engagements that improve love, happiness, and peace of mind may help long-term memory.

Forgetfulness

It is important to find out whether forgetfulness occurs because of an illness or something else. Age is one major factor. Forgetfulness in an aging person is proportionate to the number of the loss of cells.

Stress, dealing with multiple things all at once, or occupying oneself with things that are of no benefit, that is, creating a pollution of information, all affect short term memory and may cause forgetfulness.

Forgetfulness due to damage or illness

If the nerve cells of the lower occipital lobe of the brain are damaged, old information cannot be retrieved. Likewise, in case of damage to the nerve cells that are found in the temporal lobes on the sides of the brain, or due to an insufficient intake of B3 and B12 vitamins, cerebral hemorrhage or an embolism in the veins of the memory zones forgetfulness may occur.

Patients with Alzheimer indicate short term memory loss. They tend to forget visitors’ names, daily events, or the doctor’s advice.

Chronic alcohol abuse may cause damage in the hippocampus and thus in the ability to encode information.

Electroshock may also delete recent information that has been recorded in the short-term memory. Thyroid failure, Parkinson’s, hydrocephaly, schizophrenia, brain tumors, and epilepsy may also cause forgetfulness.

Some advice

Spiritual teachings and religious services have many positive aspects in our lives in addition to being our duties for expressing our servanthood to God Almighty. In Islam, for instance, principles like “enjoining good and forbidding evil,” praying at night, a brief afternoon nap, staying away from what is forbidden, reading and/or memorizing the Qur’an, and other activities may provide some protection against forgetfulness.

It is also claimed that keeping oneself busy with things that are considered morally improper, not least things that are sexually provocative in an illegitimate way, may damage neurons that are operative in memory. In order to be less affected by forgetfulness in our advanced years, it can be helpful to read spiritually and intellectually useful material, to learn and memorize new words and concepts, to keep oneself in good moral condition by engaging in charity work and helping others, and to maintain good sleep and a healthy diet

On the other hand, thinking a bit more wisely, to be able to forget (not forgetfulness) also has many benefits. Our nervous system is relaxed by forgetting, otherwise it might collapse. Forgetting old informa¬tion could well open up room for new information, although this does not mean that the information is deleted from memory; it is retrieved when needed. But, if forgetting reaches a level that is above medically ex¬pected averages, then medical help should be sought.

There are incidents of patients who are suffering from dementia and Alzheimer regaining their memory after electroshock therapy. Perhaps this is evidence that we will remember and testify for all our actions when we will have to account for them.

We live in a world full of technological devices, instruments and machines. Even if we buy them from good retailers, our cars we use to commute, or our CD-players and nowadays the mp3-players we use to listen to music one day break down, and eventually we change them. Can you imagine a TV which never gets old and can be used forever? The answer is obviously no. But we human beings have a miraculous system that always repairs itself-a system called DNA Repair. The proteins which are produced using DNA as a template, are also used to repair DNA when necessary. Before going into details of DNA repair, let us look at what DNA is, what DNA damage is, and how it occurs.

DNA (deoxyribonucleic acid) is one of four major macromolecules (the others being carbohydrates, lipids, and proteins) that constitute living things. DNA mainly contains genetic information encoded by a combination of four different DNA building blocks, nucleotides, to produce proteins. These proteins in turn play a role in cellular reactions. Genetic material is faithfully copied and passed on from generation to generation, perpetuating the characteristics of the parent and providing children with the information necessary for existence. Our sex, most of our personalities, as well as physical traits (eye color, hair color) are dependent on DNA as a part of the biological order established in our body. Moreover, even aging is a result of the shortening of the packed DNA (chromosome) through time. DNA is crucial for our body, but having such a unique molecule can come at a cost. In particular, cancer and many other disorders are thought to be caused by a lack of proper DNA-handling in cells, due to a defect in DNA repair.

DNA is a fairly stable molecule made up of two strands. Along each individual there are covalent bonds which hold sugar and phosphates together, and the two complementary strands of DNA are bound by hydrogen bonds. But, are these bonds strong enough? Are they unbreakable? To be able to function properly is DNA ever in need of maintenance? Like everything in this world, DNA too can be fragile in extreme conditions (Figure 1). Physical or chemical agents that might cause changes in DNA are commonly known as DNA-damaging agents or mutagens. Mutagens can be either endogenous (like free radicals which are produced from normal metabolic byproducts) or exogenous (like UV radiation or some toxic food chemicals). In addition, DNA can be damaged when synthesizing itself before cell division. These changes may be caused by enzymatic errors or mis-incorporation of nucleotides. Studies have shown that DNA damage, due to environmental factors and normal metabolic processes inside the cell, occurs at a rate of 1,000 to 1,000,000 molecular lesions per cell per day. While this constitutes only 0.000165% of the human genome’s approximately 6 billion bases (3 billion base pairs), unrepaired lesions in critical genes (such as tumor suppressor genes) can impede a cell’s ability to carry out its function and appreciably increase the likelihood of cancer formation.

Although there are many ways that DNA can be damaged, we are equipped with DNA repair mechanisms that can reverse the process. As soon as damage occurs to the DNA, it is detected by sensor proteins. These proteins scan the DNA all the time for any bulges or breaks. Once damage is identified the proteins tag it and DNA repair is initiated. A second precaution against damage is provided by a process called DNA Damage Checkpoint (Figure 1). Once this has been activated, cell division is delayed or comes to a halt in order to prevent the change from being passed on to any new cells.

Damage can occur on a single strand or on both strands. Depending on where or how the damage has been introduced, we have different repair systems for each type of DNA damage (Figure 2). In figure 2 we can see the difference between the original, undamaged DNA and the damaged DNA. The DNA repair systems responsible for repairing different defects are also shown in the figure to give a better idea of different DNA repair systems. Of particular interest is the fact that there are more than 150 genes that have been identified to date as being related to DNA repair. When we consider the number of possible defects that can threaten the DNA, this number is surprisingly low in comparison to the total number of genes (~ 30,000 as estimated by the Consortium of the Human Genome Project). Related to that, research in recent years has started to show that the genes which are important for one particular type of DNA repair are in fact required for different repair systems too. When we think about the enormous number of defects introduced into the DNA as opposed to the very few number of proteins involved in DNA repair (as compared to the whole genome), we can easily appreciate the perfection of the system. To give an idea of how DNA is repaired a nucleotide excision repair is shown in figure 3. At the top of the figure, UV exposure causes damage to the DNA. After that, DNA repair is initiated and recognizes the damage. The proteins (represented by circles in different colors) which are responsible for the repair act one after another to bring the DNA back to its original, intact shape.

If damage in DNA is not repaired at all, then the cells with the damaged DNA are either eliminated via a process called apoptosis or mutation occurs. The term mutation refers to permanent changes in the DNA. Although most people assume mutations are harmful, they can be silent or even beneficial depending on the region of DNA in which they occur. In the worst case, when they are deleterious, they can cause many genetically related disorders as well as cancers (Table 1). In this table, we can see different disorders which are caused by lack of appropriate repair systems.

If the rate of DNA damage exceeds the capacity of the cell to repair it, the accumulation of errors can overwhelm the cell and might also result in premature aging. Biologically, aging is an irreversible state in which the cell no longer divides, and is a protective response to the shortening of the DNA ends (telomeres). The telomeres are long regions of repetitive DNA that undergo partial degradation each time a cell is divided. Aging in cells may serve as a functional alternative to apoptosis in cases where the physical presence of a cell is required by the organism, thus serving as a “last resort” mechanism to prevent a cell with damaged DNA from dividing inappropriately. Since inappropriate division might lead to cancer, the induction of aging and apoptosis is considered to be part of a strategy to protect against cancer.

On the other hand, there is an interesting example for researchers where we see a proficiency of DNA repair activity in an organism called deinococcus radiodurans, the most radiation-resistant organism known to date. Specifically, it exhibits a remarkable resistance to radioactivity (which in turn causes double strand breaks on DNA) most likely due to enhanced DNA repair.

In this article we have tried to answer the question of what DNA repair is, how it is regulated in the cells and what the results of a deficiency in DNA repair are. Studying wonders like the DNA of our biological system is a means of contemplation that leads us to deep reflection on the intricacies of the universe. But one question remains unanswered, how has DNA learned to repair itself?

Hasan Altinbasak is a researcher at the National Institutes of Health.

References

• Lodish H, Berk A., Matsudaira P, Kaiser CA, Krieger M, Scott MP, Zipursky SL, Darnell J. (2004). Molecular Biology of the Cell, p. 963. WH Freeman: New York, NY. 5th ed.
• A physical map of the human genome. The International Human Genome Mapping Consortium. Nature 409, 934–941 (15 February 2001)
• http://www.riken.jp/engn/r-world/info/release/tress/2005/050609_2/index.html
• Wood RD, Mitchell M, Lindahl T. Human DNA repair genes, 2005. Mutat Res. 2005 Sep 4;577(1-2):275-83.
• Tom Strachan, Andrew Read. 2003. Human Molecular Genetics. John Wiley & Sons Inc.
• http://bbrp.llnl.gov/repair/html/overview.html
• http://biology-pages.info

The second leading cause of death in the United States, after heart diseases, is cancer, claiming around half a million lives every year.(1) People today are concerned more than ever about cancer and its terrible consequences. However, in the light of recent scientific findings, a very different picture can be seen: In an environment with increasing carcinogens, it is actually surprising to find most populations are cancer-free. This is because our bodies are equipped with systems to prevent cancer formation.

Cancer research over the last two decades has shown that cancer is a disease of the genome.(2) Changes in the DNA, called mutations, disrupt the regular cellular networks that control a state of delicate balance. People are continuously exposed to varying amounts of chemicals that have been shown to cause mutations in the genome which may lead to cancer formation. Exposure to harmful chemicals can occur due to being in an environment where these agents are present in the food, air or water, and also due to our own metabolism which may produce these chemicals. It has been estimated that exposure to environmental chemical carcinogens may contribute significantly to the formation of the majority of human cancers.(3)

Even though some of the mutations caused by these agents hit cancer-critical genes, cancer does not immediately develop. Furthermore, cancer is mostly seen in old age, when many mutations have accumulated in the genome. The reason why we are protected from developing cancer, even though our DNA is under numerous types of attacks everyday, is that our cells are equipped with several lines of defense against cancer formation. These built-in defenses include DNA damage repair systems, external and internal controls of cell division rate, and the programmed death of cells. All of these defenses have been given to our cells in order to protect us from getting cancer. If we were not to have these defenses, cancer would be a daily occurrence for every one.

It is possible to say that a cell’s first defense against cancer is similar to the regular maintenance of a car. One has to replace the brake pads, change the oil, etc., so that the aging of the parts will not cause failure that may lead to an accident. Similarly, chemical carcinogens from environmental pollution, ultraviolet rays from the sun, radiation from various sources, etc. all cause multiple types of damage in the DNA molecule. Therefore, our cells and genome need maintenance as well. This function is carried out by groups of proteins called DNA repair complexes. DNA repair mechanisms have been designed to correct the DNA damage before it can lead to inheritable mutations.(4)

If the DNA damage repair systems are intact, most of the damages to the genome are dealt with before they can cause problems. We observe the extent of attacks that can damage the DNA on our genome in many types of cancer where the DNA repair mechanisms are known to have been inactivated. In these cancer cells, mutations accumulate at a very fast rate, leading to more aberrant behavior. Also, individuals with defective DNA repair systems are more susceptible to developing various types of cancer.(4,5) Therefore, the first line of defense given to our cells against cancer is the ability to check and correct the integrity of our genome.

Every cell type in our body has been designed to proliferate at a certain rate that is suitable for the function of those cells. For example, neurons or muscle cells almost never divide after reaching adulthood, whereas the epithelial cells lining the interior of the intestines or under the skin divide at a fast rate continuously throughout our lives. The rate of division of a cell is mainly controlled by extra-cellular cues, i.e. a normal cell doesn’t grow or divide unless it receives growth and proliferation signals from neighboring cells.

There is a safe rate at which a cell must divide – just as a car needs to be driven at a safe speed. The requirement of cells for external stimuli in order to grow and divide is like the car’s need for someone to step on the gas pedal in order to accelerate. Normal cells cannot grow without control as neighboring cells produce growth signals when they are necessary and stop producing them in a regulated manner. A good example of the control of cell proliferation rate is seen in the wound healing process. When there is a cut in the skin, the cells adjacent to the wound are stimulated to divide rapidly by signals given from the injured cells; they divide and close the wound as soon as possible. However, when there are no wounds, there is no signal to divide and the skin cells only divide at a very slow rate, just enough to replace dying cells; this is a much slower process than wound healing. Cancer cells, on the other hand, are known to produce their own growth signals and proliferate abnormally fast and in an uncontrolled manner.(6) Therefore, the environmental control of cell division is an important barrier against cancer formation.

Cancer cells cannot divide uncontrollably unless they are independent of the external stimuli to divide. However, cancer cells can produce their own growth and proliferation signals, so they are free from external constraints. But even then, all is not yet lost. This situation of uncontrolled and rapid cellular proliferation is like a car in which the accelerator has become jammed– the car accelerates continuously and an accident is impending. In this situation the way to prevent too much speed is to step on the brake of the car. Similarly, in a cell, there are a set of genes called tumor-suppressor genes, which are responsible for stopping cell division upon excessive growth stimuli.(7) These genes act like brakes in cell division and prevent further progression into a malignant state. In many cancers,(8) it has been shown that these genes have been inactivated. If the brakes of the car are functional, you can safely bring your car to a stop and fix the problem that caused the accelerator to jam. Similarly, if a cell starts to divide too rapidly, it can stop dividing and repair the damage that caused the uncontrolled growth. Therefore, tumor suppressor genes represent a third line of defense.

If all the previous safety valves fail, there is one more defense to cancer. A situation in which a cell with harmful mutations promotes its own proliferation and cannot abort the division process is similar to one where the accelerator of the car is jammed and the brakes don’t work. In this case, in order to prevent greater damage, one can choose to hit a wall or a tree to stop the car– this will total the car, but will prevent further damage to others. Similarly, if a cell begins to grow uncontrollably and can’t slow down its rate of division, a process called apoptosis, or programmed cell death is initiated. In apoptosis, the cellular DNA and cellular compartments, like lysozomes, Endoplasmic Reticulum, and Golgi are degraded, and the cell shrinks in size. In the end, the cell dies and is absorbed by neighboring normal tissue. Therefore, the programmed death of an aberrantly behaving cell is another way that the body is protected from cancer. As expected, in cancer cells defects in this last line of defense are observed as well.(9)

These four mechanisms, i.e. DNA repair, external/ internal cell division suppression, and programmed cell death, are only the ones that we are aware of at this time. In addition to these, there are multiple levels of other redundant safety checks. All these safety features work without our knowledge or will. Findings from cancer research show that the design of cells was carried out so intelligently that even the carcinogenic environment which we produce today was accounted for within the genes of the very first human being.

Notes

1. Cancer Statistics 2006. 2006, American Cancer Society.

2. Vogelstein, B. and K.W. Kinzler, “The multistep nature of cancer.” Trends Genet, 1993. 9(4): p. 138-41.

3. Wogan, G.N., et al., “Environmental and chemical carcinogenesis.” Semin Cancer Biol, 2004. 14(6): p. 473-86.

4. Dixon, K. and E. Kopras, “Genetic alterations and DNA repair in human carcinogenesis.” Semin Cancer Biol, 2004. 14(6): p. 441-8.

5. Jiricny, J., “The multifaceted mismatch-repair system.” Nat Rev Mol Cell Biol, 2006. 7(5): p. 335-46.

6. Brattain, M.G., et al., “Growth factor balance and tumor progression.” Curr Opin Oncol, 1994. 6(1): p. 77-81.

7. Hanahan, D. and R.A. Weinberg, “The hallmarks of cancer.” Cell, 2000. 100(1): p. 57-70.

8. Coleman, W.B. and G.J. Tsongalis, “Molecular mechanisms of human carcinogenesis.” Exs, 2006(96): p. 321-49.

9. Dlamini, Z., Z. Mbita, and T. Ledwaba, “Can targeting apoptosis resolve the cancer saga?” Future Oncol, 2005. 1(3): p. 339-49.

The environmental crisis humanity faces at this stage in their development is an outward manifestation of the internal crisis arising from the break with traditional beliefs and values, and their surrender to the disease of ‘problem denial’ characteristic of modern urban, industrialized societies. This state of mental and spiritual sickness takes man down a vicious and destructive spiral. Human-centred, short-term gain and economic surplus-oriented societies have led people to put their trust in science and technology to solve their problems, regardless of the cost to ‘others’. This way of life is not sustainable and creates new and worsening problems, doing perhaps inevitable long term damage to ‘other’ people, other species, the environment as a whole.

Industrialization has led to a simplified, throw-it-away world view which encourages people to dominate and manipulate all available resources in a frantic race for growth in levels of self-indulgence. The causes of environmental overload or degradation are pollution of water, air and land, and depletion of resources. Urbanization and industrialization where large amounts of pollutants are concentrated in small volumes of air, water and land have led to the overloading and disruption of the natural dilution, breakdown and recycling of the chemicals essential for life. The effluent of fertilizers, pesticides, toxic heavy metals, and (partly or wholly) treated industrial waste, is allowed to run off into lakes and streams. The effects are already very tangible: nauseating smells and tastes, smog causing reduced atmospheric visibility, corrosion of metal work, erosion of buildings; reduced tree and crop production; a decrease in biodiversity-each year at least 51,000 species in all become extinct, often as direct consequence of human activity; serious damage to human health-as in the spread of infectious diseases, irritation and diseases of the respiratory system, genetic and reproductive defects, and cancers (for example of skin and liver).

The scale and rate of environmental degradation demand serious and urgent reform. We desperately need to change our attitudes and concepts conform more with the laws of nature as ordained by God. Only if we do it so can we hope for true success in this world and the Hereafter.

As noted, excessive and wasteful use of material resources is a major factor in environmental degradation. We have three types of material resources. First, deep-mined non-renewable (exhaustible) resources such as petroleum, coal, natural gas, and minerals such as copper, aluminium, iron, and uranium which are purified from ores supplied by the earth’s crust. Fossil fuels are finite and could be exhausted quite quickly at present rates of consumption; further, when burned, these fuels are converted to waste heat and exhaust gases which are serious pollutants.

Second, there are perpetual resources, namely solar energy, wind power, geothermal energy, and flowing water. These must become our main future sources of energy.

Third, the potentially renewable resources so-called because, they can be replaced through natural processes on a human life-time scale. Examples are trees in forests, grasses, wild animals, fresh surface water, in lakes and streams, and most ground water, the earth’s most valuable resource. If these resources are used at a rate that does not reduce their availability, they can yield a sustainable source of energy. However, when the natural replacement rate is exceeded, then the supply is depleted and environmental degradation results. Some examples are typified by the covering of productive land with water, concrete, asphalt, or buildings to such an extent that crop growth declines and wildlife habitats are lost. Excessive removal of fresh water from aquifers and from surface waters leads to water scarcity. Deforestation without adequate replanting causes destruction of wildlife habitats where timber-growth cannot be sustained.

Alarmingly, nearly half of the world’s original expanse of tropical forests have been cleared. Each year, about 171,000 km2 of tropical forest are destroyed. These losses reduce biodiversity because niches for thousands of plants and animals are destroyed with the trees.

Around 35% of the world’s coastal and inland wetlands have been drained, built upon, or seriously polluted (e.g. the ‘Golden Horn’ in Istanbul). Most of our wastes accumulate in the oceans. Oil slicks, floating plastic debris, polluted estuaries and beaches, contaminated fish, are just a few of the ugly scenes that result. However, man’s carelessness not only affects other species: world-wide, an estimated 16 million people lose their homes and land due to environmental degradation alone.

Resource depletion or scarcity can be absolute or relative. Absolute scarcity occurs when supplies of a resource .are insufficient or too expensive to meet present or anticipated future demands. For example, the world’s finite supplies of petroleum oil may be used up within the next 50 years decades at present rates of consumption. Relative scarcity occurs as a result of unbalanced and inequitable distribution of a resource which, if equitably distributed would meet the demand of everyone in need.

Relative scarcity dominates the world scene at present: industrialized economies of the West, the United States especially consume a huge disproportionate share of material and energy resources at the expense of other nations. This further widens the gap between the rich and the poor countries. It is a fact that the rate of damage inflicted upon the environment, and hence the damage to the stability and security of others’ lives, has been greater in this past century than since the beginning of man’s history. The Muslim World today, once the pioneer of true civilization is being steadily corrupted by serving the lifestyle of the Western powers. The balanced, traditional lifestyle which conforms with the law of God and hence is more environment-friendly nature is being eroded at alarming speed. The Muslims and other victims of modern civilization lack control over their lives, once self-sustaining, and are forced into the global ‘cash economy’ manipulated by a small, cynical elite who gamble, quite literally, with commodity and stock prices without the least concern for the millions of human lives disrupted and destroyed as a result.

Mankind are heading toward an abyss of anxiety and insecurity while the natural world deteriorates around them. Unless we make a concerted and sustained effort to recover the fitrah state, a life-style that accords with the balance and order of creation, destruction and disorder on a hitherto unimagined scale await us in this life and, in the next, the torment of knowing we failed our responsibility. For in that life we shall be questioned in detail about what we did in this; each of our senses and limbs and organs will bear witness against us; and we will account even for every drop of water we used well or wasted.