There are many ongoing studies into fasting, a practice prescribed across many religions. Increasingly, there is evidence to support that intermittent fasting is beneficial to human health.

The opposite of fasting – overeating – has been revealed to be a major culprit in many illnesses, including cancer, obesity, and heart disease. For many years, the medical consensus was that fasting, i.e. prolonged hunger, too, could have deleterious effects on the human body. From kidney failure to loss of muscle, fasting was believed to be harmful – thus calling into question the benefits of this widespread religious commandment.

People of faith – including Muslims – have long believed that God wouldn’t recommend a practice that was harmful to the body. The hardships and troubles that accompany a religious practice are not too extreme for people aware of their servitude to God: they regard their trials as a testament of their faith. Part of that faith is the certainty that God wouldn’t recommend a harmful or unbearable practice.

In this article, we will share with you two unknown benefits of fasting that have been recently discovered.

Regenerating stem cells

There is a substantial body of evidence showing that staying hungry during certain periods of the day heals the body’s metabolism, hastens loss of fat, decreases oxidative stress,* and improves the functions of the tissues that make up various organs including the liver, the intestines, and the brain. The first of the two new discoveries about the underlying processes, however, provides a missing piece of the puzzle by helping us understand the incredible changes hunger triggers in stem cells.

Researchers at MIT, Duke University School of Medicine, and Whitehead Institute for Biomedical Research in Cambridge published an article recently on stem cells, indicating that part of stem cell’s mystery could lie in the oxidation (burning) of fat in the mitochondria [1]. Omer H. Yilmaz and his fellow researchers found that a 24-hour fast hastens fat breakdown in intestinal stem and special progenitor cells of rats.

To run the study, Yilmaz and colleagues let the mice go hungry for 24 hours to study the state of their stem cells. They found that the functions of intestinal stem cells increased, and fat metabolism quickened, in both young and aged mice, even during early periods of hunger. They saw that the body’s tapping into fat for its energy needs maintained the health and strength of the intestinal stem cells. Moreover, they noticed that if the aged mice did not fast, they started to lose their ability to break down and use fats for energy expenditure.

The researchers obtained more interesting results as the studies progressed. It was found that a single period of hunger for 24 hours boosted renewal of intestinal cells – and the stem cell functions increased even more significantly in aged mice. Another interesting finding was that mice with damaged intestines that were fasted recovered faster than those that were fed.

“My lab is really interested in understanding how diet, in general, can be used to improve tissue function,” Yilmaz said. “One of the tissue types I study is the intestine. In my lab we study the intestine because it’s one of the largest organs in the body. It’s also a tissue that experiences rapid cellular turnover.” [2]

The intestine is lined by a single layer of cells, Yilmaz explains, that turns over every 5 to 7 days. The workhorses of the intestinal lining and this cellular turnover are intestinal stem cells. These cells must retain a high level of function or cellular health in order to replenish the intestinal epithelium on a regular basis. Intestinal stem cells are particularly important in terms of repairing intestinal damage caused by gut infections and chemotherapy, for example.

The single layer of epithelial cells needs to be renewed every 5-7 days: the aids and enzymes secreted in the intestine for digestive and absorptive activities damage cells despite the protective mucus layer, and some other cells already burst and die as they empty their secretions. Moreover, some medications, particularly chemotherapy, cause the destruction and breakdown of the epithelial cell layer. However, fast-multiplying stem cells replenish the epithelial cells. Stem cells are very active and young and have the ability to divide and multiply continuously.

Dr. Yilmaz also says:

“As we age, stem cells in the intestine as well as in many other tissues of the body, including in the blood and nervous systems, become less functional. We believe that reduced adult stem cell function contributes to some of the decline of function associated with old age. My lab is very interested in studying low-calorie interventions to delay this decline. As a field, we’ve known for over 100 years that low-calorie states such as fasting or caloric restriction can have positive effects on tissue health and aging. We’ve seen evidence that fasting during times of intestinal infections that lead to diarrhea may promote healing of the intestinal lining, for example.” [2]

This quote emphasizes the importance of the issue. Yilmaz adds that despite all this knowledge, the cellular mechanisms of this renewal have not been discovered, and he and his team are working to find out how fasting and hunger enable this recovery.

Stem cells become happy in fat!

The researchers discovered through the experiments that the stem cell function could be brought about in hungry mice by the burning (oxidation) of fatty acids in intestinal cells. When they stopped the fat metabolism through genetic engineering, they noticed that the benefits of fasting on intestinal stem cells were negligent.

In the present dietary conditions, we obtain nearly 60-70% of our energy from carbohydrates or sugar, 20% from fats and 10% from amino acids. Yet an interesting finding revealed by Dr. Yılmaz and his research team is that we essentially obtain much greater energy from using fats once we fast. According to their experiments on mice, during fasting, the intestinal stem cells in both young and aged mice switch from carbohydrates to fats as the primary source of energy, and this shift enables improvement in stem cell functions.

It is not yet known what underlies the fat metabolism that boosts stem cell functions in response to fasting, but it is observed that stem cells work better when they burn fat. The ability to metabolize fats efficiently decreases with age.

It is likely that this hastened metabolism – encouraged by certain diets, like the keto diet, where the amount of fat ingested is raised to 70% and carbohydrate intake is limited to 5% – helps with epileptic seizures and similar neurological disorders: the ketone bodies generated during metabolism of fats are used as energy sources by the brain.

According to Dr. Yilmaz, if fasting can improve the functions of intestinal stem cells through metabolism of fats, the key is the mitochondria, the powerhouses of the cell responsible for this function. Fat metabolism, or the immediate breaking down or “burning” of the fat entering the cell, is carried out in the mitochondria. Disrupted energy generation associated with aging and decreasing mitochondria can be a reason for the brain’s susceptibility to age-related illnesses. Positive developments in brain functions can therefore be viewed in connection with the correlation between fasting and the oxidation of fatty acids.

Cleaning by fasting

Just like the spring cleaning in our homes, our cells need a thorough cleaning to function properly. Wrongly folded protein particles, remains of damaged organelles, broken molecular pieces, and aged cells that can no longer divide should be disposed out of our cellular structure. Fasting perfectly performs the task of cleaning these wastes and clearing the area in the cell.

“Everything has zakat (a means of cleaning), and the zakat of the body is fasting.” (Ibn-i Majah, Siyam: 44)
“Fasting is a protective shield.” (Bukhari, Sawm: 2)

What is autophagy?

Autophagy is the compound of two ancient Greek words: auto (self) and phagos (eating). What is meant by “self-eating,” is the breaking down and recycling of protein waste and old, impaired molecules by intracellular digestive organelles called lysosomes. In this way, proteins or cellular organelles are digested and taken out of circulation. We can liken autophagy to garbage collection.

Japanese researcher Yoshinori Ohsumi’s study, which brought him the 2016 Nobel Prize for Medicine, found that the autophagy that occurs inside the cell due to fasting or starvation plays an important role in preventing ageing, infections, and tumors. If autophagy breaks down, many illnesses may be triggered, including cancer. Conversely, if autophagy activity is regular, tumors may be suppressed – depending on the stage of development and type of tumor. Cancer research has long focused on channeling these autophagic activities. Restriction of food intake through fasting shows promise: it may protect normal cells while triggering autophagy and thus increasing the effect of cancer treatments. Autophagy might offer solutions or treatment options for other illnesses, too, including inflammatory diseases [3], neurodegeneration [4], metabolic and cardiovascular diseases [5], obesity [6], and metabolic disorders.

Preclinical studies have shown that dietary restrictions by fasting contribute to the increase of a person’s lifespan and slow the development of age-related diseases such as cancer and neurodegenerative and cardiovascular diseases [7].

* Oxidative stress: The damage caused as a result of excessive proliferation of free oxygen radicals released from foods that spike blood sugar (with high glycemic index) as metabolic waste. A good example of oxidative stress is the browning of certain foodstuff such as apples, bananas, etc. sometime after they are peeled.

References

1. Yilmaz, Omer H. et al. 2018. “Fasting Activates Fatty Acid Oxidation to Enhance Intestinal Stem Cell Function during Homeostasis and Aging.” Cell Stem Cell, Vol. 22, Issue 5, May 3, pp. 769–778.
2. Paige Brown Jarreau. 2018. “Eating (Or rather, Fasting) Our Way to Rejuvenated Stem Cells?” in Life and Tech @ LifeOmic. June 7. A Medium Corporation.
3. Cadwell K. 2016. “Crosstalk between autophagy and inflammatory signaling pathways: balancing defence and homeostasis.” Nat Rev Immunol.16 (11): 661–75.
4. Menzies FM, Fleming A, Caricasole A, Bento CF, Andrews SP, Ashkenazi A et al. 2017. “Autophagy and Neurodegeneration: Pathogenic Mechanisms and Therapeutic Opportunities.” Neuron. 93 (5):1015–34.
5. Bravo-San Pedro JM, Kroemer G, Galluzzi L. 2017. “Autophagy and Mitophagy in Cardiovascular Disease.” Circ Res. 120((11)):1812–24.
6. Lavallard VJ, Meijer AJ, Codogno P, Gual P. 2012: “Autophagy, signaling and obesity.” Pharmacol Res. 66 (6):513–25.
7. O’Flanagan CH, Smith LA, McDonell SB, Hursting SD. 2017. “When less may be more: calorie restriction and response to cancer therapy.” BMC Med. 15(1):106.

Zhu et al. Immunosuppression via loss of IL2rγ enhances long-term functional integration of hESC-derived photoreceptors in the mouse retina. Cell Stem Cell, January 2017.

Your ability to read these words relies on your retina, the eye’s nerve center. Light passes through the lens and iris and strikes the retina at the back of the eyeball, which consists of light-sensing rods and cones. This process allows you to see these letters. When things go awry in the retina, people experience partial or complete loss of vision; to date, no efficient treatment has been found to stop or reverse blindness. Researchers have been trying to transplant new photoreceptor cells into the retina for the last decade, but the success has been very limited, and the transplanted cells usually did not survive long enough to restore vision. In a recent study, researchers were able to restore vision in completely blind mice by transplanting photoreceptors derived from human stem cells. They demonstrated that the blind mice were able to perceive light as late as 9-months following the transplantation. The key to their success was simultaneously blocking the immune response that causes transplanted cells to be rejected. The researchers determined that the mice which lack the immunodeficient IL2 receptor gamma (IL2rl), a specific immune cell receptor that rejects transplanted foreign cells, experienced longer-term survival of the transplanted cells. These findings give a lot of hope that the same stem cells used to cure blind mice may also be used to treat humans. It is now possible to identify other small molecules or recombinant proteins to reduce interleukin 2 receptor gamma activity in the body, increasing the possibility the body will accept transplanted stem cells.

The moon may be formed from a group of smaller moonlets

Rufu et al. A multiple-impact origin for the moon. Nature Geoscience, January 2017.

The moon’s formation was a unique event, but it remains poorly understood. However it came to be, our moon – like all the moons in the solar system – has a stabilizing effect on our planet. Scientists have always been puzzled why Earth only has one moon, while other planets have multiple – for instance, Saturn and Jupiter have 62 and 67 moons respectively. A new study suggests that the Earth may have had numerous smaller moons at some point, but they crashed together to form our current moon. Earth was born about 4.5 billion years ago, and scientists think the moon began forming a short time later. The leading explanation for the moon’s origin, known as the giant-impact model, suggests that our moon formed when a large protoplanet, Theia, crashed into Earth 4.4 billion years ago, tearing out a moon-sized cloud of debris. But the new study ran 1000 sophisticated simulations modeling this ancient impact and found that instead of one giant collision, the Earth likely experienced many smaller ones. Each of these smaller impacts would have torn away debris that could have coalesced into a moonlet. The current moon was likely formed by the combination of 20 moonlets over the course of 100 million years. While the new model proposes some compelling ideas, it cannot explain how the Earth got its tilted axis, which was also explained by the giant impact model. Experts say more lunar samples through the Chinese Lunar Exploration Program will help us to differentiate between the two models in the near future.

Food poisoning bacteria eat cancerous tumors

Mehta et al. Bacterial Carriers for Glioblastoma Therapy. Molecular Therapy – Oncolytics. December 2016.

Who doesn’t hate food poisoning? Salmonella is responsible for more than a million cases of food poisoning every year. But a team of researchers found that Salmonella might be our best ally in fighting the most aggressive form of brain cancer known to man, glioblastomas. Glioblastoma is an extremely aggressive form of tumor. Patients diagnosed with it have a mean lifespan of only 15 months. The cancer is protected from conventional drug and radiation-based therapies due to the blood-brain barrier. Surgery is also an imperfect option, because if even a single cancerous cell is left behind, it can spawn new tumors. In a recent study, scientists genetically engineered the bacterium Salmonella typhimurium so that it does not attack the human gastrointestinal tract, but rather the glioblastoma tumors. Specifically, they made the bacteria deficient in the crucial metabolite purine. Since tumors are packed with purine, genetically engineered bacteria were attracted to the tumors like flies to honey.  Scientists also integrated two new genes into Salmonella to produce the compounds Azurian and p53, which both cause cells to self-destruct, specifically in low-oxygen environments such as the interior of a tumor, where bacteria are rapidly multiplying. With this method, both the tumorous cells and bacteria eventually die off over time. A major challenge in treating glioblastomas is that the tumors spread with no clear edge, making them difficult to completely surgically remove. So designing bacteria to actively move and seek out these tumors, and to express their anti-tumor proteins only in hypoxic, purine rich tumor regions, has great therapeutic potential. In rats, the treatment basically doubled the survival rate and lifespan of those suffering from glioblastoma. Although success in rodent-based trials does not guarantee the same for humans, the results are nonetheless impressive and promising.

Frostbite Protection in Mice Suggests an Antifreeze Glycoprotein
Heisig M. et al. PLOS ONE, February 2015.

Some animals such as ticks and fish have anti-freeze proteins that protect them from extreme cold conditions. Anti-freeze proteins typically prevent cold damage by limiting the formation of ice crystals that would otherwise lead to tissue damage. However, warm-blooded mammals, including humans, do not have such proteins and can suffer injuries from severe cold, such as frostbite. In a recent study, scientists tested whether the anti-freeze proteins of other species can protect mammals from such cold injuries. They genetically introduced an anti-freeze protein from the black-legged tick into a live mouse. When mice tails were exposed to cold for seven days, 60% of the transgenic mice showed no visible signs of frostbite, compared to only 11% of the controls. In addition, inflammation response from the immune systems of the transgenic mice was dramatically lower.  This study is the first to demonstrate a protein’s ability to boost frostbite resistance in an adult mammal. Although any potential human applications of anti-freeze proteins are far away, this study spotlights two future directions. First, anti-freeze proteins could potentially be utilized to extend the lifetime of organs prior to transplantation. Second, anti-freeze proteins may provide cellular protection for people with certain autoimmune diseases, such as scleroderma, that are characterized by cold sensitivity.

Smartphones as earthquake warning devices

Crowd-sourced earthquake early warning
Minson ES et al. Science Advances, April 2015.

The cellphones in our pockets function as cameras, calculators, flashlights – and now earthquake sensors. During an earthquake, even a few seconds can make a difference between life and death. Japan has the most advanced early warning system, which saved many lives during the 2011 Tohoku earthquake with a magnitude of 9.0. However, these systems are expensive and not practical at a personal level. A new study proposes that smartphones can be utilized to detect earthquakes via their GPS (Global Positioning System). Although GPS in smartphones use a relatively coarse method of positioning compared with many sensitive instruments, they can detect as little as six inches of displacement, which can be sufficient for earthquake detection. Scientists first tested the accuracy of smartphone GPS systems by shaking a phone and comparing the recorded displacements with a sensitive scientific instrument. After many analyses in different contexts, they concluded that smartphones could reliably detect earthquakes of a magnitude 7.0 and above. However, an obvious problem with this approach is that smartphones are always in motion as we walk, drive, or simply play with our phones; how can a smartphone differentiate a real earthquake from a routine motion? Scientists then came up with a solution called a “trigger” in which an earthquake alarm would only be activated if a smartphone and its four closest neighbors recorded the same amount of displacement. Experts are still skeptical about how well this system would work in a real-world situation. But, the benefit of crowd-sourcing earthquake detection is well recognized; all you need is a smartphone app.

Ocean acidification linked to the greatest extinction

Ocean acidification and the Permo-Triassic mass extinction.
Clarkson MO et al. Science, April 2015

A recent study suggests that ocean acidification caused by extreme volcanic activity triggered the greatest extinction of all time. This extinction event took place approximately 252 million years ago, and over the course of 60,000 years, it erased more than 90% of marine species and 60% of land animals. The researchers analyzed ancient rocks from the deserts of the United Arab Emirates, which were formed on the ocean floor about 250 million years ago. They specifically examined the ratios of boron and carbon isotopes. These chemical measurements revealed that oceans went from alkaline to highly acidic over the course of a few thousand years, which is very quick in geological terms. Scientists suggest that a huge pulse of volcanic eruptions discharged immense amounts of carbon dioxide into the atmosphere and acidified the oceans. This resulted in possibly fatal conditions for marine life; when combined with the destruction of food chains, most marine life went extinct. The amount of carbon added to the atmosphere during the mass extinction was predicted to be greater than today’s fossil fuel reserves. However, alarmingly, the rate of carbon released at the time was very similar to modern emissions. Oceans today are rapidly acidifying due to increased CO₂ emissions by human activities such as the burning of fossil fuels; the average pH has dropped by 0.1 units since the beginning of the Industrial Revolution. Oceanographers cautioned that a dramatic rise in the acidity levels of oceans affects all marine life, particularly shellfish fisheries around the world. We can only hope that the future does not resemble the past.

Meinecke et al. Turbulent amplification of magnetic fields in laboratory laser-produced shock waves, June 2014, Nature Physics.

A supernova is the explosion of a massive star which releases a burst of radiation that can be as bright as 10 billion suns. Such a massive amount of radiation can shine throughout the entire universe for several light-years. Supernovas are triggered either when the fuel within a star ignites or when a star’s core collapses under extreme gravitational forces. Supernovas have already taught us very important lessons about the history of the universe. For example, these explosions have provided solid evidence that the universe is expanding. Supernovas can also tell us a lot about how old stars die and how new stars are born. When a star goes through a supernova explosion, it leaves behind a skeleton made of expanding dust and gas that scientists call a remnant. These star-remnants spread around space. They might end up on earth or other planets, or they could form the energy source of a new star. Since the best way to understand supernovas is to actually explode a star, researchers recently developed a technique to simulate small-scale supernovas in a lab environment. To do this, scientists used lasers that are 60,000 billion times more powerful than a laser pointer. They focused the laser beams on a thin carbon rod inside a gas-filled chamber. The lasers heated the chamber to over 1 million degrees Celsius, which caused the carbon rod to explode and expand out through the low density gas – just like how exploding stars speed through space. The experiment revealed that as the blast passes through the grid, it becomes irregular and turbulent. They also noticed that the magnetic field was dramatically higher within the grid than without, suggesting that the magnetic field was amplified by the generated turbulence. The supernova system developed in this study holds the possibility of helping us better understand how the universe was formed and evolved, and could provide some insight into how magnetic fields were first created.

Young blood: The fountain of youth?

Villeda SA et al. Young blood reverses age-related impairments in cognitive function and synaptic plasticity in mice. June 2014, Nature Medicine.
Sinha M. et al. Restoring systemic GDF11 levels reverses age-related dysfunction in mouse skeletal muscle. June 2014, Science.

Two recent studies of lab mice showed that transfusions of blood from younger individuals reverse the effects of aging in their elders. One research group showed that neural damage of mice with age-related cognitive impairments could be reversed by such transfusions. Alternatively, injecting the younger plasma into the brain was also very effective at repairing neural damage. Another research group showed that blood from younger mice repaired age-related heart defects in older mice. Researchers further discovered that high levels of the protein GDF11, present in the blood of younger mice, were the key for rejuvenation. Researchers proposed that blood from younger mice contains molecules with anti-aging properties that awaken the stem cells of the brain and heart muscles and thus initiate the rejuvenation. These studies are incredibly encouraging for combating Alzheimer’s disease, heart disease, and many other age-related diseases; however, a comprehensive set of clinical tests needs to be conducted before testing the effects in humans.

“Chameleon” plant discovered

Gianoli E. and Carrasco-Urra F. Leaf mimicry in a climbing plant Protects against herbivory. May 2014, Current Biology.

Scientists thought for many years that camouflage and mimicry were only observed in the animal kingdom. A newly discovered wood vine in Chile, Boquila trifoliolata, has been found to transform its leaves to mimic a variety of host trees. B. trifoliolata is the first plant ever shown to imitate multiple hosts. This is a rare trait called “mimetic polymorphism” and it was only previously observed in butterflies. As B. trifoliolata climbs onto a tree’s branches, it changes the color, size, shape, orientation, and even the vein patterns of its leaves to match the surrounding flora. When the same vine crosses over to a second tree, the size of its leaves can even increase 10 times  to match the second host plant. According to scientists, mimicry may protect the vine from plant-eating herbivores such as weevils and leaf beetles. It is perplexing how a plant can distinguish between individual trees and keep changing its physical characteristics. Odors, chemicals, or microbes that are released form host plants are potential candidate mechanisms for this intriguing plant behavior.

Like all omnivorous foods, peppers – both hot and sweet – have been created in unique, wise ways to make them appealing to eat and to help reproduce.

Plants and their fruits are sustenance for herbivores, including humans. They are often brightly colored – be it red, orange, yellow, purple, or green, inviting us to a delicious food. But not all plants are meant to be eaten. Indeed, some plants are designed to be unappetizing, either through look or smell; some even have thorns, or sticky, hairy surfaces to deter us from eating them. Another remarkable way that plants are protected against herbivores is the presence of unique chemicals that induce vomiting and pain, or may be toxic.

Many edible plants need to be eaten – it’s how they spread their seeds. Thus, they produce juicy, tasty skin and sweet-smelling aromas. Why, then, are hot peppers different? Though they are nicely colored and juicy, and sweet smelling, they are also hot, and not terribly pleasant for animals to eat.

A recent study at New Mexico State University’s Chile Pepper Institute determined the hottest chili to be the Trinidad Moruga Scorpion Chili. It was chosen from among 125 varieties. Researchers dried and ground it to powder, to isolate its active compound. This way, they were able to determine that the Trinidad Moruga Scorpion reaches about 1.2 million units on the Scoville heat scale. It is so potent that it could induce sweating and tears, and of course puts the mouth on fire.

Figure 1. Molecular mechanism of TRPV receptor activated by capsaicin. TRPVs are located on the surface of nerve cells where they normally respond to changes in temperature by releasing calcium ions. Those ions signal to intracellular machinery to fire nerve action to inform the brain about increased levels of heat. Capsaicin in hot peppers mimics this system, and thus fools brain to think mouth is hot.

What make hot peppers hot?

Animals are equipped with receptors, like TRPV1 in the mouth’s nerve endings, which sense heat. Hot peppers produce a chemical called capsaicin. Capsaicin binds to and activates TRPV1 receptors; thus we feel a heat similar to a burning sensation. In reality, capsaicin does not actually increase the temperature in the mouth, but instead mimics the same process (Figure 1). Since capsaicin mainly dissolves in oil instead of water, drinking water does not help much to get rid of the burning sensation. Cold water provides only temporary aid. However, the drinking of ayran (a Turkish yogurt drink) relieves hotness by removing capsaicin due to the presence of oil in ayran. Interestingly, although mammals have receptors for capsaicin, scientists have recently discovered that birds don’t.

Capsaicin deters mammalian consumption

It is an interesting phenomenon that peppers are hot but need to be eaten to propagate their seeds in different environments, which is done through the droppings of animals. If this is the case, why are hot peppers made unpleasant with capsaicin? To figure out the wisdom behind this contradiction, Joshua Tewksbury performed a study with a group of mice and birds, and found that birds do not distinguish between sweet and hot peppers in their diet. In this study, both mice and birds ate the same amount when fed with food mixed with sweet peppers. However, mice refused to eat foods mixed with hot peppers, while birds happily ate such food. Moreover, analysis of the droppings of birds and mice showed that the seeds passed through the bird’s digestion systems were intact and fully fertile and could germinate, while seeds eaten by mice were either crushed or semi digested so that they were not fertile. Thus, the role of capsaicin in hot peppers is to deter mammals that destroy their seeds while not disturbing birds. This is a great example of ingenious interdependence.

Capsaicin as antifungal agent of peppers

Figure 2. Capsaicin is not only protective against mammals but also fungus contaminations. A) Insects make peppers prone to fungus contamination by causing harm. B) Healthy pepper C) A pepper with fungal contamination. Modified Image from Tewksbury lab.

The infinite wisdom of capsaicin protects peppers against fungus as well. Another study by Tewksbury showed that hot peppers are relatively protected against fungal infections. Tewksbury demonstrated that increased doses of capsaicin inhibit the growth of fungus. This finding is in parallel with lower fungus growth in hot peppers compared to sweet peppers.

But what about insects? How could peppers be protected from insects?

Adaptations against insects

Interestingly, the skins of hot and sweet peppers have different levels of thickness. It has been suggested that this gives an advantage to sweet peppers. Furthermore, this protective layer is made of lignin, which is made of the same material as capsaicin and helps to protect from other threats. This allows peppers to adapt to many different environments. For instance, in the presence of fungal contamination, a pepper might be able to produce more capsaicin and decrease lignin production, or vice versa.

Why do we like to eat hot peppers then?

Humans differ from mammals in their love of hot peppers. There are different explanations why we like to eat hot peppers, despite them being painful. Some experts assert that hot peppers are good for our health by lowering blood pressure, having antimicrobial effects, and increasing salivation thus making a boring diet fun. On the other hand, some experts approach it from the perspective of human emotions and argue that we are actually after the pain produced by hot peppers. In addition, there are some studies suggesting that capsaicin could also suppress other pains.

Hot pepper or capsaicin as pain suppressor

Capsaicin in hot peppers could be used as a pain suppressor, as some studies suggested. A study using mice lacking TRPV1 heat receptors showed that the increased long term activation of TRPV1 by capsaicin could relieve pain following the accumulation of high doses of Ca2+ in the cells. This is accomplished by the suppression of both cellular activities and the transmission of pain through nerves.

Hot peppers are hot and we love them. It seems like we will continue consuming them. As every other art of creation, hot or sweet peppers are likely to have many more levels of wisdom awaiting us to discover.

References

• Tewksbury Lab. Retrieved from: http://faculty.washington.edu/tewksjj/res_pai.html on 18.2.2012.
• Yalgın. Ç. 2012. Acı biberler niye acı? (Why Are Peppers Hot?) Açık Bilim. Retrieved from: http://www.acikbilim.com on 18.2.2012.
• Zivkovic, B. 2006. Hot peppers – Why are they hot? A Blog Around The Clock.

The findings in mice imply that humans might also possess similar characteristics. This increases the possibility and brings hopes of having a baby even at older ages along with treatments in the future, just like in the miraculous story of Prophet Abraham and Sarah as narrated both in the Qur’an (ad-Dhariyat 51:24-30) and the Bible (Genesis 21:7), showing us one aspect of the possibility and ultimate limits of knowledge and technology that humans can attain one day so that these miracles can become true, though to some extent, with the advancement of medicine.

Bone borne eggs

An interesting study showed an unexpected source of oocytes in the bone. Study by Tilly’s group at the Harvard Medical School in 2004 showed that cells in the bone marrow of mice could be a source of oocytes that are developing in the ovaries [1, 2]. Their first observation was the expression of genes related to egg cells in the bone marrow samples of mice. To test the possibility of bone marrow cells as a source of new oocytes, they chemically generated infertile mice. Treating mice with two chemotherapy drugs called cyclophosphamide and busulfan causes infertility. Once they treated the mice with these drugs, the mice had extensive damage in their ovaries along with an end in new oocyte production in their follicles. Ovarian follicles are spherical aggregations in the ovaries which periodically produce oocytes. Remarkably, when they transplanted bone marrow from female donors, they found a number of oocyte containing follicles (about several hundred). Interestingly, the appearance of those oocytes were rapid and thought to be due to circulating oocytes originating from the bone marrow and developing as they travel through the blood stream. Although they don’t have the evidence that those cells could be fertilized, findings could lead to fundamental changes in the current understanding of the female reproductive system.

Tilly and colleagues also report that bone marrow and blood transplants could also induce the development of oocytes in a genetically infertile mice model (which has a mutation in ATM gene) [3]. This mutant mice lack follicles and developing oocytes and are unable to produce mature germ cells (egg producing cells). Their study shows that bone marrow or blood transplant from healthy donors induces production of oocytes in this mice model. They conclude from those studies that bone marrow could be a source of germ cells to the ovaries throughout adult life. Their findings are somewhat supported by the clinical studies on cancer patients who were expected to be infertile but they could have babies after bone marrow transplant.

Another study on the circulating cells for female fertility used parabiotic (the union of two mice through an exchange of blood) mice model. This study by Eggan and colleagues tested the capacity of circulating bone marrow cells to generate ovulated oocytes and could not show any contribution of bone marrow cells to ovulated oocytes [4]. Blood or bone borne oocytes are highly debatable but bone marrow cells, at least, might have a role in enhancing women’s fertility. This might lead to the treatment of infertility. In addition, it might bring new opportunities for those dreaming of having a baby even at a late stage, but requires much additional research to be realized.

Lab & bone borne sperms

Sperm formation is known to continue throughout adulthood. It involves various steps of cellular differentiations. Maturation of sperms in the body takes more than a month in most mammals. Trials to mimic this complex process in petri dishes failed to demonstrate the production of normal, fertile sperms.

Scientists had dreamed of growing sperms in petri dishes for years. Recently, researchers in Japan developed a technique that allowed production of fertile mammalian sperms in a petri dish [5]. Attempts to make such mature sperms usually failed due to meiosis, a specific type of cell division that halves the number of chromosomes. Meiosis is very essential step for sperm cells to get ready to fuse with an egg. Ogawa and colleagues demonstrated that meiosis of sperm cells lay in a simple change to standard petri conditions. They tried various petri conditions but they ended up with a special serum free medium that is commonly used for growth of embryonic stem cells. Several weeks later, they observed formation of mature sperm cells and even half of them had flagella, a tail-like structure that sperm cells use to swim. Injection of those sperms into egg was also able to produce offspring. In addition, when they used frozen testis tissues of newborn mice, they could grow sperms as well. This discovery in reproductive biology is likely to be beneficial not only for people having infertility problems associated with sperm maturation but also children that undergo cancer therapy which destroys fertility. It is known that chemotherapy impairs fertility. Adults could freeze their sperm before such treatment, but young boys can’t. This new discovery offers such patients hope. In addition, this finding opens new avenues for protection of endangered animals that might die before reaching sexual maturity. It is a matter of time for the same technique to be applied to humans and other species.

There are also reports suggesting the generation of male germ stem cells (sperm producing cells) from bone marrow [6, 7]. Mesenchymal stem cells, which are derived from the bone marrow, have shown to differentiate into male germ cells. Studies testing the effect of retinoic acid and testicular extracts showed to induce human bone marrow stem cells to differentiate into male germ cells as shown by male germ-cell specific marker expressions. Another approach tested the possibility that bone marrow-derived stem cells would differentiate into germ cells when transplanted into the mouse testis. Using GFP positive bone marrow cells transplantations, it has been demonstrated that bone marrow-derived stem cells can also be induced to differentiate into germ cells. Interestingly, there seems to be a connection between bones and fertility.

Bones and fertility

The Qur’an tells the story of Prophet Zachariah, peace be upon him, when he secretly prayed to God to ask for a successor. He said “My Lord! My bones have grown feeble and my head glistens with gray hair from old age…” (Maryam 19:4). His prayer was accepted and the angels came with the glad tidings of his son, John. He was surprised as to how he could have a son while his wife was barren and that he had already reached infirmity in old age. It has been said by scholars that weakness of bones here refers to weakness in engaging in sex due to old age and gray hairs as a sign of infertility. It is also worthy to mention another verse where the creation of human is described as happening from a lowly fluid that gushes forth the vertebra and rib bones: Let human, then, consider from what he has been created. He has been created from some of a lowly fluid gushing forth. It proceeds (as a result of incitement) between the (lumbar zone in the) vertebra and the ribs (At-Tariq 86:5−7). As commentator Ali Unal explains, these verses refer to both the mechanism of the ejection of the seminal fluid and where it is emitted [8], which is a relatively recent discovery in biology. Remarkably, the Qur’an mentions two major bones where this fluid is emerging. Our current knowledge in medicine do not say anything about the role of ribs in reproduction or fertility but both the Islamic and Judeo-Christian traditions mention the creation of Eve from Adam’s ribs, peace be upon him. Could this refer to the relation between bones and fertility? God knows best. Lastly, it is of importance to note that one of the symptoms of menopause is the loss of bone mass. Isn’t it amazing how mysterious events regarding bones and fertility are taking place beyond our control and knowledge?

Ali Fethi Toprak is a PhD candidate at University of Texas Southwestern Medical Center.

References

1. Johnson, J., et al., Germline stem cells and follicular renewal in the postnatal mammalian ovary. Nature, 2004. 428(6979): p. 145-50.
2. Vogel, G., Reproductive biology. Controversial study finds an unexpected source of oocytes. Science, 2005. 309(5735): p. 678-9.
3. Johnson, J., et al., Oocyte generation in adult mammalian ovaries by putative germ cells in bone marrow and peripheral blood. Cell, 2005. 122(2): p. 303-15.
4. Eggan, K., et al., Ovulated oocytes in adult mice derive from non-circulating germ cells. Nature, 2006. 441(7097): p. 1109-14.
5. Sato, T., et al., In vitro production of functional sperm in cultured neonatal mouse testes. Nature, 2011. 471(7339): p. 504-7.
6. Hua, J., et al., Derivation of male germ cell-like lineage from human fetal bone marrow stem cells. Reprod Biomed Online, 2009. 19(1): p. 99-105.
7. Lue, Y., et al., Fate of bone marrow stem cells transplanted into the testis: potential implication for men with testicular failure. Am J Pathol, 2007. 170(3): p. 899-908.
8. Unal, A., The Qur’an with Annotated Interpretation in Modern English. Vol. Qur’an 86:5−7, 51;24−30 and 19:4. 2009.

Original article: Kim P. et al, ACS Nano (2012, online ahead of print)

Frost formation on aircrafts at high altitudes poses major safety threats and high-maintenance costs. Now, Joanna Aizenberg with her research team present a solution in their recent publication reporting on outstanding capabilities of a surface coating to prevent frost formation on metal surfaces. The technology called SLIPS (Slippery, Liquid-Infused Porous Surfaces) was inspired by the slippery surface of the carnivorous pitcher plant, which enables the plant to capture insects. “Some of the most extreme examples in biology can provide the most amazing and unexpected ideas…” says Aizenberg, who is a professor at the Wyss Institute for Biologically Inspired Engineering at Harvard University. Rendering surfaces slippery is not new to scientists, and the earlier inspirations also came from biology. Mimicking the surface of the leaf of another plant (Nelumbo nucifera, or commonly known as the Lotus plant), scientists have been successful in fabricating surface coatings that would repel water-based dirt, but Lotus-inspired coatings failed for oily substances. On the other hand, Aizenberg’s SLIPS technology offers a single solution for repelling any type of accumulated unwanted material. The pitcher plant thus offers a solution that virtually proves to be the “silver bullet” in generating non-sticky coatings as described again in Aizenberg’s own words: “In following its example, we should be able to develop a platform that works for almost any sticky problem, no matter how seemingly unrelated, whether it’s ice accumulation, bacterial attachment, environmental contamination, clogging of pipes, marine biofouling, or graffiti, rather than having to come up with a host of individual solutions.” Thanks to the wondrous design in the pitcher plant, it looks like doctors will be delivered from replacing bacteria-contaminated arterial stents, and we can all give a kiss goodbye to frosty freezers.

2- Airborne bird flu virus possesses a great risk

Original articles: Herfst S. et al, Science 336, 1534 & Russell C.A. et al, Science 336, 1541.

Science magazine recently published a special issue (June 22, 2012 issue) on the H5N1 infection (a.k.a. bird flu) with two reports revealing the pandemic (a disease prevalent throughout an entire country, continent, or the whole world, such as AIDS) potential of bird flu. Bird flu virus has so far killed millions of birds and many more millions of birds were culled to stop the propagation of the virus. Thankfully, this virus has not yet caused a pandemic in humans mainly because of its inability to spread easily among humans. One mechanism that makes viruses highly contagious is their ability to spread through air, such as through the nose and mouths of people when they cough and sneeze. Viruses that spread through air are called airborne viruses. One big difference between bird flu virus and the more recent swine flu virus (H1N1) was that swine flu is an airborne virus and bird flu is not, and therefore swine flu caused a mild pandemic in 2009. As reported in these studies, researchers identified several genetic mutations that will cause bird flu virus to become airborne. Viruses undergo mutations all the time and unfortunately some of these identified mutations have already started taking place in circulating virus strains. This poses a great risk. One important aspect of these reports is that they were written about a year ago but withheld since now, because of concerns about misuse of this information to pose a threat to humanity. Now that the information is public, our hope is that it will be used to monitor the virus closely and be prepared if bird flu virus transforms into an airborne virus.

3- Not all bacteria are the same after all

Original article: Chung H. et al, Cell 149, 1578 (2012)

The impact of our own bacteria on human life has been intensely researched in recent years. One of the common ground is that humans acquire many useful bacteria over their existence. However, this microbial flora constantly changes as the conditions do. Therefore, the real number of 500 to 1000 microbial species inhabiting mammals is anybody’s guess. Nonetheless, some scientists did not shy away predicting a connection between having a specific microbial flora to avoid certain diseases. A recent article by Chung et al presented an interesting clue why constant change in microbial flora, especially if that leads to a loss of important bacteria, may be linked to the increase in human autoimmune disorders. “For every cell in your body that is you, that contains your specific genetic information, there are approximately nine foreign bacterial cells, primarily in your digestive tract and even on your skin,” said Dennis Kasper, professor at Harvard Medical School and senior author on the paper. To address the question if microbial affects immune system development, authors compared two groups of mice, both of which had never had bacteria in their intestine before the experiment. One group of mice received mice microbial flora and the other received human microbial flora. Both groups had similar number of bacteria in their digestive tracks. However, authors observed a stark contrast between the two groups in terms of the level of immune cells in intestinal tissues. Mice that received human flora had surprisingly low number of immune cells compared to the mice that received mouse flora, which is native to mice. When this experiment was repeated with rat microbial flora, astonishingly, similar immune deficiency was observed. “I was very surprised to see that. I would have expected more of a half-way response,” Chung said, considering how closely rats and mice are related. The study points out that we really need to preserve our own microbial flora that has been tailored for us. Disrupting this balance by means of current antibiotics overuse may have detrimental effects in the future.

Original article: Olzsak T. et al, Science (2012, epub ahead of print)

It has been known by epidemiologists that people who grew up in farms are less likely to acquire immune diseases such as asthma, allergies, inflammatory bowel disease and multiple sclerosis when compared to people living in cities. Such observations have been the roots of “hygiene hypothesis,” which essentially points out the beneficial effects of being exposed to infectious agents. Supporting this theory, a recent study at Harvard Medical School showed that exposure to symbiotic bacteria has a long lasting beneficial effect on the immune system development. “We as a species are not exposed to the same germs that we were exposed to in the past,” said the co-author Dennis Kasper, a microbiologist at Harvard Medical School in Boston. In this study, published in Science, the researchers compared germ-free mice to mice with normal bacterial flora. Germ-free mice showed significantly higher levels of invariant natural killer T (iNKT) cells in their colons and lungs. “We made the serendipitous observation that these cells were dramatically enriched in the lung and colon in mice that lacked any microbes,” said the co-author Richard Blumberg, the chief of gastroenterology at Brigham and Woman’s Hospital in Boston. Body’s own production of elevated iNKT cells correlated with higher susceptibility to inflammatory bowel disease and allergic asthma in germ-free mice. Most strikingly, the study showed that exposure to these bacteria in late age did not lower the susceptibility to these immune diseases, indicating that the bacterial exposure needs to be early in life to boost the immune system. After all, broad-spectrum antibiotics for babies may not be such a good idea.

2- Giant chickens of Jurassic Park

Original article: Xu X. et al, Nature 484, 92 (2012)

Many of us undoubtedly learned a lot about dinosaurs from the famous Sci-fi movie Jurassic Park, but who would have imagined that some gigantic feathered dinosaurs would be running along with our favorite monster T-Rex? Paleontologists have recently made an incredible discovery in Liaoning Province of China. They found a set of perfectly preserved fossils that belong to a previously unknown species of dinosaurs. These 125-million-year-old feathered giant dinosaurs represent the largest feathered animal species ever lived on earth. The adult one is predicted to be at least 9 meters (30 feet) long with a weight of 1400 kg (~3000 pounds), which is approximately 40 times bigger than the Beipiaosaurus, largest known feathered dinosaur. New gigantic feathered dinosaurs are given a Chinese-Latin name Yutyrannus huali meaning a “beautiful feathered tyrant.” Simple filament like structures as well as the relatively small sizes of feathers seem more similar to feathers from a baby chick than the plumes of an adult bird, suggesting that Yutyrannus used feathers not for flying but for body temperature insulation, perhaps under the harsh climate conditions of that age. Paleontologists are really excited to see that how much more we have learned about dinosaurs over last 15 years and they predict that many different feathered meat-eating dinosaurs lived before and they are still yet to be discovered.

3- Stardust mystery revealed

Original article: Norris B.R.M. et al, Nature 484, 220 (2012)

Heavy elements are formed in the cores of stars and are crucial in formation of celestial structures like our earth. When an intermediate-mass star dies, it triggers a cosmic sandstorm that lasts thousands of years ejecting more than half of its mass into space. Our Sun is expected to go into a similar phase in around 5 billion years. Scientists observed these sandstorms for years but it was a mystery how these particles found could leave the vicinity of the stars and find their way into interstellar space. Computer simulations hinted that these sand-like particles could not be that small, otherwise they would be evaporated by the immense heat of the dying star. Scientists using the Very Large Telescope in Chile had a chance to explore these stars in a greater detail and discovered that the size of these particles is around a micrometer. This size might seem very small to us but for these particles, it is large enough to behave like mirrors for the light rays coming out of the star instead of absorbing them. Since light also behaves like a particle, the momentum transferred by this reflection helps particles to accelerate to the speeds like 10km/second. As the lead author of the study, Barnaby Norris from University of Sydney says: “The dust grains are like lots of little sails catching the wind, or in this case, starlight.” The material that comes out of the stars is recycled during the formation of new stellar objects like our old planet.

4- Babies understand more than we think

Original article: Bergelsona, E. & Swingley, D., P.N.A.S. 109, 3252 (2012)

Most babies do not say a meaningful word until they are a year old. It was not clear whether they knew the meaning of the words prior to the speaking age. It is easy to ask the question on whether the babies understand words but it is hard to scientifically measure it. The researchers from the University of Pennsylvania devised an ingenious experiment to test the hypothesis whether the 6-9 months babies understood the common words. During the experiment babies sat on their parents’ lap in front of a computer while some images of body parts or foods were shown on the screen. The parents were given instructions through headphones about what to say to the baby about the image on the screen. Babies were monitored by an eye-tracking device to measure their attention being directed to screen. The researchers designed a control environment by pairing a body part and a food item. For instance, if a banana and some hair were shown on the screen, the researchers measured the time that the baby fixated on the banana when the parent instructed the child to look at the banana versus when the parent instructed the baby to look at the hair. 33 infants of ages 6 to 9 months and 50 toddlers of ages 10 to 20 months were recruited for this study. The study convincingly showed that the babies fixated longer on an object when they were instructed to do so. Moreover, as the age of the babies increased the period of fixation stayed pretty much constant until 14 months, but jumped dramatically afterwards. The reason behind the jump in 14 months begs further research. Now, the researchers want also to test the vocabulary of the babies and whether the babies also understand the abstract concepts.

Original article: Czupryn, A. et al., Science 334, 1133 (2011).

Neurons are a highly specialized group of cells that transmit electrical stimuli to elicit responses in the body. This high specialization comes with a price: with few exceptions, neurons cannot divide to replace nonfunctional ones. Over the past decade, cell therapy, that is treatment of a disease by introducing new cells, has emerged as a new hope for neurological disorders such as spinal cord injury, Alzheimer’s disease, and Parkinson’s disease, albeit with numerous challenges. One of the major problems in the field is to make the newly-introduced cells integrate into the neural circuitry of the host organism. This proof-of-concept study showed that it is possible for transplanted neurons to functionally integrate into the host brain and cure obesity in a specific genetic mouse model. This genetic mouse model lacks the ability to sense leptin, a hormone that regulates body weight and metabolism. Thus, these mice are prone to obesity and diabetes. The authors transplanted progenitor neurons isolated from the hypothalamus-a part of the brain that regulates numerous functions including metabolism, hunger and body temperature-of normal embryonic mice to the hypothalami of newborn diseased mice. Twenty weeks after the transplantation, cells were shown to be functionally integrated into the native circuitry. Integrated neurons were able to create electrical stimuli, transmit signals and, unlike the native neurons, respond to the hormone, leptin. Amazingly, transplanted mice were 30% lower in body weight and diabetes-free compared to the obese non-transplanted counterparts. The results were dramatic, despite the fact that only a few of the transplanted neurons were actually converted to the neurons that play a role in energy metabolism and leptin response. The authors explain this phenomenon by stating that the transplanted neurons may work as “antennas” to sense leptin and regulate other neurons in the native circuitry. Although current research is far from human application, it is still an important step towards treatment of detrimental neurological diseases.

2- A new record in solar cell efficiency

Original Article: Yella, A. et al., Science 334, 629 (2011).

Since their discovery in 1991, dye-sensitized solar cells (also known as Grätzel cells) have offered great potential despite their low efficiency values. They consist of dye-soaked titania nanoparticles coupled to an iodide-based electrolyte that allows for absorption of light and its conversion to electricity through the fast transport of electrons. According to a report in Science, researchers from ecole Polytechnique Federale de Lausanne (EPFL) have substantially improved the efficiency values over 12%, making this type of solar cells a feasible contender to the incumbent silicon solar cells. To store the most sunlight, these cells absorb the colors of the light spectrum with the highest energies and reject the rest such as the green light. In addition to the increase in cell efficiency, Grätzel and coworkers have also reduced their cost by replacing expensive ruthenium dyes with a zinc-based dye. Finally, they have improved the voltage output by using a cobalt electrolyte, a redox system that is more compatible than the previous iodide systems. This new system with improved components has also increased the theoretical maximum efficiency to 30%, which will require further optimization in device design and engineering to achieve. The only major drawback is the use of organic solvents potentially limiting the efforts for large-scale fabrication.

3- IQ can still change in teenage years

Original Article: Ramsden S. et al., Nature 479, 113 (2011).

Intelligence quotient (IQ) is a standardized measure of human intellectual capacity that takes into account a wide range of cognitive skills. IQ is generally considered to be stable across the lifespan, with scores at one time point being used to predict educational achievement and employment prospects in later years. However Prof. Cathy Price and colleagues have found that verbal and non-verbal IQ can rise or fall in the teenage years. They tested 33 teenagers-19 boys and 14 girls-in 2004, when they were 12 to 16 years old, and again in 2008, when they were 16 to 20 years old. Each time, the teens took IQ tests that measured their verbal and nonverbal abilities. Then, using magnetic resonance imaging, the researchers scanned the teenagers’ brains while they performed verbal tasks, such as reading or naming objects, and nonverbal tasks, such as solving visual puzzles with their hands. The idea was to match their test scores with a picture of their brain structure and activity at each time. The test results revealed dramatic changes between their first testing and their second: verbal and nonverbal IQ scores of participants rose or fell by as many as 20 points (on a scale with an average score of 100). Some teens improved or declined in either their verbal or nonverbal skills, while others improved in one area and declined in the other. The brain scans mirrored the score differences. For example, in teens whose verbal IQ scores had increased, the scans showed increased gray matter density in a region of the brain activated by speech. Teens whose nonverbal skills had improved showed changes in a brain region associated with motor movements of the hand. The authors note that these were the largest changes observed, and that there might be many more that were not noticed.

4- A coordination path from an infant’s heart to the mother’s heart

Original Article: Feldman, R. et al., Infant Behavior and Development 34, 569 (2011).

A group of researchers sat 40 pairs of mothers and 3-month-old infants face-to-face, equipped with sticky skin electrodes on either side of their hearts. Beat for beat, mother and child’s hearts thumped together almost instantly as they shared loving looks or contented coos. This cardiac coupling worked only for moms with their own babies, and only when the duos synchronized smiles and other cheerful social behaviors. The researchers suspect that when humans mirror each other’s facial expressions, they may switch on specific areas in the brain that tell the heart when to thump. Melding with mom lasts longer than just a few beats, however. Babies who don’t tune in with their mothers are less empathetic as teenagers, according to previous work from the same group. Premature infants or those whose mothers have postpartum depression may be most at risk for losing this social skill because they miss out on early opportunities to interact with their mothers. The authors state that future research is required to examine the impact of interaction synchrony on other physiological processes, such as hormonal release or brain activation.