Aging

Melih Mert

Oct 1, 2005

I will start with the cliché: “man is born, grows, ages, and finally dies.” So this cycle of life is inevitable, although at different times in history the speed of this process has varied tremendously. In early times, when there was purity in nature, it is narrated that Prophet Noah lived for 950 years. Whether other people at the time had that long a life span is not known for certain, but this suggests that human beings lived longer lives in earlier times. Later, at some point it was reduced to a mere 30 or 40, years due to wars and diseases like the plague. Nowadays, lifespan depends on the level of prosperity in a society, ranging from 33 in Zimbabwe, for example, to 80 in Sweden. But then, why bother to avoid or prolong a life whose end is inevitable, namely death? If you consider the time needed for a human to mature and be educated, you will see that these days, people are assumed to have gained experienced after the age 30, and that the longer they live, the more wisdom they can gain and impart and the more good deeds they can accomplish for this world and the Hereafter. So prolonging the life span is not just a decadent materialistic pursuit, rather it can actually bear beneficial fruit for humanity, both spiritually and materially.

However, as one’s age increases, most bodily functions peak and then start to diminish. A better aging strategy would be to age in the healthiest possible manner; i.e., keeping the physical and mental functions as sharp as possible, in particular the memory, so as not to lose human dignity in old age.

Aging and Memory

As one ages, reactions start to slow, the speed of understanding and the level of concentration diminish. The precipitous decline of dopamine-containing neurons in the human brain after age 45 is a universal characteristic of the aging process. The nigrostriatal region of the brain is richest in dopamine and undergoes the most rapid aging of any brain area. Age-associated depletion of dopamine also accounts for less noticeable symptoms, like a decline in physical drives and brain functions. These reactions are mostly on a mental or psychological level. In addition to these, wrinkles appear in the skin, hairs gray, and joints become gnarly. Perhaps, most important of all, is that according to recent research carried out on the brain, by the time most people hit 40, their brainpower starts to weaken. This does not mean that people become incompetent, just a bit slower in the cognitive process. This phenomenon is called “generalized slowing” by psychologists. According to James Birren, the Associate Director of the Center on Aging at the University of California, Los Angeles, the first signs of aging appear on tests used to measure mental speed and acuity, in which people count the number of lights flashed on a screen, for instance, or trace a complicated pattern while looking at a mirror.

“But eventually the down-turn affects almost everything we do,” says Birren, “From how fast we hit the breaks when a car pulls in front of us to how quickly we learn new skills on the job or remember old what’s-her-name’s name.”

Then the question is whether the slowing process is unavoidable. According to psychologist Robert Dustman, the answer to this is yes. One of the country’s top experts on aging and the brain, Dustman directs the Neuropsychology Research Laboratory at the Veterans Affairs Medical Center in Salt Lake City. He’s just turned 70 and shows no signs of slowing down himself. “It is true that when we compare 20-year-olds with 60-year olds on almost any test that measures the speed of information processing, younger people on average score significantly better than the older ones,” he says, “But that does not have to be. There is a simple way I can ward off the scourge of slowness,” Dustman says. And the way to do this is to stay in shape.

At first it seems to go against common sense that in some way a mindless act like jogging or striding around a park is relevant to the speed of thinking. But Dustman explains the connection in a very logical way.

Every cell in the body requires a continuous supply of oxygen and nutrients to function at its peak. But surprisingly, no cells need a greater oxygen supply than the gray matter that rests between our ears. The brain, although it makes up only 2% of our body weight, uses up 25% of the glucose and oxygen supply.

Now suppose a person slips out of shape, their heart gets lazy, the arteries get clogged, the blood flow to capillaries slows down, and the oxygen and nutrient supply to the brain falls us. As a result, neurons get less than they need to function properly, the electrical signals slow down, and hence the mind slows down. A recent study shows that blood pressure (or lack of it) is highly correlated to memory; so much so that, a reduction of it causes the memory to weaken.

But getting older does not mean that one must face a full-scale slowdown, Dustman says. The problem is that by 45, when the brain is quickly falling into decline, most of us neglect to perform the activities that keep the arteries open, the heart strong, and blood flowing; namely exercise. Dustman’s own studies suggest that working out might be an antidote. In one of his studies, he ran 60 male volunteers, half in their twenties, half in their sixties, through the standard mental tests. As expected, the younger group had higher mental speeds. But when Dustman looked closely at the older group, he noticed that the ones who were exercising or had remained active had a brain speed that was comparable to that of the younger set.

The tests included actions as simple as pushing a button each time an X appeared in a long string of O’s to memorizing numbers and symbols. “On many measures,” says Dustman “the older men in good condition scored just as well as men 30 and 40 years their junior.” In real life, that is, they could find a number in a phone book or remember that sensible is a synonym for rational.

When one exercise, in other words, the sections of the brain which control movement and balance are fired up, the electrical signals zap back and forth along the nerves from the brain to the muscles and tendons. The eyes, the inner ear, and other sensory nerves all roll into action. The benefits of these can be detected clearly in the brainwaves and electrical impulses recorded by researchers.

Indeed, in Dustman’s study, the older men who were still fit had surprisingly youthful-looking brain waves. They produced more alpha waves, a pattern associated with calmness under pressure, and had steeper peaks and valleys in waves, which signifies an ability to block out distractions. Furthermore, when subjected to a sudden flash of light or a sound blast, they were faster to produce a wave called P-300, which is associated with fast reactions. “People in good shape can really focus,” says Dustman. “They can pen a letter to a friend without the sound of children playing downstairs disturbing them. They can fill out tax forms correctly after reading the directions once.” For someone who’s out of shape, the news is grim. In addition to problems that range from overweight to heart disease and diabetes, the results of a sedentary life style, it turns out that the brain will very likely start to weaken as well. Still, Dustman is optimistic. He once encouraged 42 sedentary people over 55 to exercise (walking or jogging) three times a week. After four months, the aerobic capacity of the volunteers increased 25 % and they scored better on mental speed tests. In light of this study, Dustman thinks that even easy exercise, such as brisk walking can speed up the minds of people after years of inactivity. The time required varies, however. In similar studies, it took about a year to observe an increase in the speed of the brain.

But it is not time that is important here; the goal is rather not to lose brain capacity until a very old age. It would be better if one were always to keep in shape, as it is easier to keep something that works running than to start it up again once it has slowed down. “The real benefit seems to come from making a lifelong habit of staying active,” says Dustman.

It is better to maintain a regular routine of exercises than to start up new ones. Researchers at the University of Illinois compared middle-aged lab rats who padded daily on a running mill to rats who negotiated a complicated obstacle course of rope bridges and seesaws a few times a day. Predictably, both groups got more blood flowing to the brain. But the obstacle-mastering rats had 25% more hard-wired connections between neurons. Assuming the same is true for humans, then exercises which require more brain activity are potentially more rewarding.

Aging and Sleep

The obvious dangers of not getting enough sleep include mental fuzziness, an increased chance of accidents, illness, psychological problems, and decreased productivity at work or school. But Dr. Eve Van Cauter wrote in the prestigious medical journal Lancet that less sleep can actually speed the process of aging. In her informative study, young men who were allowed to sleep only 4 hours each night showed signs of aging in less than a week. Their glucose tolerance dropped considerably, and they started to release cortisol, the stress hormone, at a greater rate than normal.

Sleep offers the body an opportunity to heal and rebuild itself. Pro-sleep nutrients might help in this cause. For example, it has been shown that nutritional supplements containing zinc, magnesium, and pyridoxine (vitamin B6) , among other benefits, help sleep efficiency. A herbal amino acid 5-hydroxytryptophan is another promising sleep aid to use in times of extreme stress. Among sleep promoting herbs from traditional Chinese medicine are ziziphus spinosa (jujube), schisandra chinensis, and bupleurum chinense (Chinese thoroughwax). These herbs seem to relax the muscles and soothe the central nervous system. Sleep is and remains to be the most precious source of energy replenishment.

Melatonin: A God-given Sleeping Pill

Melatonin is a natural molecule made by the pineal gland, which is located in the brain. Melatonin is made from an amino acid called tryptophan. Tryptophan is an essential amino acid, that is, the body cannot make it; we need to get it from the foods we eat. Tryptophan is found in wide variety of foods. As we consume tryptophan during the day, the body converts it into serotonin, an important chemical for the brain that is involved with moods. Serotonin, in turn, is converted into melatonin. This conversion occurs most efficiently at nights.

Melatonin helps to set and control the internal clock that governs the natural rhythms of the body. Each night the pineal gland produces melatonin, which helps us to fall asleep. Research about this molecule has been going on since it was discovered at Yale University by Dr. Lerner in 1958, but recently there has been a great deal more attention being paid to melatonin. About a thousand articles on melatonin are published annually. One major reason is that scientists are discovering that melatonin is not only associated with deep sleep, but also with our hormonal, immune, and nervous systems. Research is accumulating about melatonin’s role as a powerful antioxidant, its possible anti-aging benefits, and its immune-enhancing properties.

Aging and Free Radicals

A free radical is a molecule that contains an unpaired electron through reactions with the essential element oxygen. These molecules “steal” electrons from nearby molecules to complete that final electron pair for stability. Then they are no longer free radicals, but they convert the new combined molecule into a new free radical. In a living organism, this process can cause a chain reaction of severe cellular damage, unless prevented.

The theory that free radicals are agents of bodily destruction is gaining widespread acceptance, as is the value of antioxidants in preventing such an occurrence.

According to the journal Annals of Clinical and Laboratory Science, the excess of free radicals in our body, i.e. “the domino effect”, is a critical factor in many health problems. An interesting and concerning fact about free radicals is that they cause the same reactions within the cells that occur during exposure to radiation. Free radicals released in the body destroy even proteins, the essential constituents of the body that regulate hormones and enzymes and that make up nerves, muscles, skin, and hair. It is usually suggested that antioxidants are used to fight these harmful free radicals. Fruits and vegetables are plentiful in vitamins A, C, and E, the key antioxidants. Polyphenols, which are found in grapes and green tea extracts are potent antioxidants. In fact, scientists have found out that procyanidins are the most promising polyphenols. In Japan, scientists have discovered that they may be 50 times more powerful than vitamins C and E in fighting free radicals. Alpha-lipoic acid, which is soluble in both water and lipids, can neutralize free radicals throughout the body. In fact, alpha-lipoic acid is involved in so many different antioxidant functions that it has been called the “universal antioxidant.” Citrus bioflavonoids and certain fruit and vegetable pigments are also strong free radical fighters.

Deprenyl: An Anti-aging Treatment?

Deprenyl (selegiline) provides selective protection against age-related degeneration of the dopamine nervous system. It is the only inhibitor used in clinical practice. The rate at which dopamine neurons age is quite variable. Before age 45, dopamine levels stay quite stable. Starting at 45, the decrease in average dopamine content in healthy people is linear, at 13% per decade. When it reaches 30%, the symptoms of Parkinson appear.

The sensitivity of the dopaminergic nervous system to oxidizing free radicals has been well established. The protective effect of deprenyl in lessening the neurotoxic effect of the oxidants (6-hydrpxydopa and 6-hydroxydopamine) appears to correlate with increased antioxidant enzyme levels. The increase in the antioxidant level is proportional to the deprenyl intake.

There as yet has been no definitive study of the long-term use of deprenyl in healthy people as a life-extension and cognitive-enhancing drug. But there has been extensive animal research. The lifespan of deprenyl-taking rats is significantly greater than normal rats, in fact, all the control rats died before the first deprenyl-taking rat died. Early research with deprenyl in humans (early-diagnosed Parkinson patients) shows delayed development of symptoms. Deprenyl has also been established as a treatment for Alzheimer’s disease. Eventually, deprenyl has the potential of becoming a general treatment for aging in people above the age of 45.

Conclusion

Although we know for sure that there cannot be an absolute cure for aging, the results of it can be slowed down considerably. Soundness and health of mind are desirable traits for all ages, not just for the elderly. After many years, many elderly people lose much of their memory and mental capacities; this occurs just at the time when they can pass on all their wisdom and experience to the younger generations. Hopefully, with the advent of science and technology, the deficiencies in the brain due to aging can be avoided to a certain extent. The solution lies in a balanced collaboration of modern medicine and traditional natural cures that have been practiced for centuries.

References

  • Life expectancy around the world http://www.mrdowling. .com/800life.html
  • Peter Jaret, (1997) THINK FAST- from Health Magazine, http://www.brain.com/TFarticle.html
  • Ray Sahelian, M.D., (1997) “Melatonin: Nature’s Sleeping Pill,” http://www.brain.com/melatonin.html
  • Ward Dean, M.D., and Steve Wm. Fowkes. “Deprenyl: A Universal Anti-aging Strategy?,” http://www.ceri.com/ deprenyl.htm
  • Spiegel, K. et al. (1999), “Impact of sleep debt on metabolic and endocrine function,” Lancet; 354 (9188):1453-9.
  • Amtoft-Nielsen, J., M.D. (2002), “Researchers Find Sleepless Nights Speed up Aging,” Journal of Longevity, Vol. 8/No.5: 38-39.
  • Abraham, I., M.D. (2002). “The Domino Effect - The Cause of Rapid Aging?,” Journal of Longevity, Vol 8/ No. 4: 36-38.