The Longevity Stakes Reversing The Effect of Aging.

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Hesiod, the Greek poet who lived some 3000 years ago, knew exactly how the human life span was determined: It all lay in the hands of the daughters of Zeus and Themis. They spun the thread of life and as they cut it, a person's life span was determined by the length of the thread allocated to him. Today, nearly three millennia hence, the molecular basis of the aging process has begun to be elucidated piecemeal.

What is aging though? Age is characterized by organic exhaustion and the loss of capacity to perform functions that are a given in youth and peak of individual life. These signs begin to take hold with sexual maturity and advance slowly but inexorably until the maximum life span is reached. Gray hair, wrinkles and loss of hearing in the upper audible range are as much a part of aging as deteriorating eyesight and physical shrinkage in the body itself. These signs must, however, be clearly distinguished from similar, even parallel, changes resulting from illnesses such as dementia and osteoporosis.

Humanity may well be on the verge of a new era as biomedical research unravels basic mechanisms thought central to the aging process. Combined with breathtaking advances in technology, such as mammalian cloning, stem cell technology, tissue and cell engineering, a new optimism is being fueled that aging may be halted or even reversed. While that eternal dream of humanity will have to await a far greater technological prowess, the upshot of these developments has been that the effects of aging can be better managed now than was possible before. Thus the increasing emphasis on "successful aging," as opposed to usual aging, has taken hold, which improves the quality of life well into the golden years rather than aging passively and considering the inevitable physical deterioration as fait accompli.( n1-n3)

The basic precept of successful aging promises neither an increased life span nor the reversal of the aging process. Implicit in successful aging is the distinction between biological vs. chronological aging. Whereas chronological age, in an individual cannot be reset despite the claims and wishes of enthusiasts, biological age can be modulated for optimal health at later stages of life. In other words, a 60-year-old individual will remain 60 years old and nothing can change that incontrovertible fact, but the biological age could potentially be reset. Many an effort is afoot to reset the biological dock of various organs technologically. For instance, there is considerable impetus to push the technological envelope to "farm" spare organs from transgenic animals and even to rejuvenate tissues via cloning. Despite the unabashed enthusiasm, this is unlikely to come to pass any time soon. In contrast, efforts to revive and rejuvenate say, the withered pineal gland to produce more melatonin, to rejuvenate the pituitary to naturally secrete growth hormone or to regulate thyroid function could conceivably have a rational basis in reversing the biological clock of an individual.

How might that work? To illustrate the point let us consider the case of a professional friend of mine, Jonathan, a highly dedicated and bright biomedical researcher at one of the top-notch medical schools in the country. (Jonathan is a fictitious name to protect the privacy of my acquaintance.) I lost touch with him after I made a transition to industry a few years ago. When I met him after five years, roughly two months ago, I was somewhat surprised to see the deterioration in his general health. Even though he is in his late 50s, Jonathan looked as if he had aged well beyond his chronological age. If I had not known him, I would have guessed him somewhere in the vicinity of 70 years or so. Jonathan always had rather egregious lifestyle. He smoked incessantly, he drank generously, his dietary habits were atrocious, he did not exercise regularly and lived a rather circumscribed life within the confines of the academe. When he and I met recently, Jonathan complained about his weight, high blood pressure, high cholesterol and triglyceride levels, difficulty in breathing and general malaise. More disconcertingly he complained about losing interest in his work and bemoaned the fact that he had not had a "good idea" in years. In short, Jonathan was a walking time bomb that could explode any time to his very own detriment. Time indeed, had left its unmistakable mark on Jonathan.

Jonathan's complaints are not as unique as one might think at first blush. As I give talks to various groups and as I field questions during radio interviews throughout the country, almost invariably there is someone whose concerns about their health remind me of Jonathan's. Should people like Jonathan simply resign themselves to age rapidly and live with considerable anguish that usually accompanies ill health, recognizing that a healthy lifestyle in earlier years would have obviated their lot? Hardly! That is where successful aging figures prominently.

Unless, of course, one is genetically predisposed to develop certain conditions such as coronary artery disease, neurodegeneration, cancer and other diseases, an individual can take numerous steps to hold physical deterioration at bay and begin to enjoy better health. Nutritional intervention, however, can also be a powerful tool to prevent chronic, age-related diseases, such as osteoarthritis, hormonal insufficiency and other such conditions. After all, with aging, as the bodily functions become less and less efficient, chronic diseases develop gradually as the attrition to the body increases, which is just as much due to the metabolic functions inside the body as it is on account of persistent environmental assaults. Nutritional management modulates these slow processes, which gather momentum over long periods of time, and clinically present themselves at a time certain as a tsunami.

Various hypotheses attempt to explain the aging process.( n4) The mechanistic model, according to which the gradual loss of strength is the natural consequence of continuous and ineluctable damage to the cells. This process of wear and tear mostly affects those organs in which the cells no longer divide, as in the brain, heart and kidneys. Free radicals are the main cause of such damage as they indiscriminately attack DNA, proteins and fat, which may be irreversible. Inasmuch as the body does have mechanisms to cushion the deleterious effects of these pernicious agents and repair the damage, with advancing years it loses its ability to effectively counteract ravages unleashed by them. Free radicals can be thwarted with antioxidants such as vitamins C and E to name but a few. In fact free radicals may also be critical to the pathogenesis of diseases in which chronic inflammatory response is the underlying cause.

Promising evidence suggests that caloric restriction may be a reasonable approach to limit not only the damage to the body but also to prolong life. Traditional societies in the Old World have routinely subscribed to the notion and admonished growing children and young adults to "leave one-third stomach empty." That is de facto caloric restriction. Even though the data obtained in well-controlled clinical trials are not in, it stands to reason that "leaving the stomach empty" may have profound implications for good health.

How does this apply to Jonathan? He admittedly used to gorge on food. The food that is not immediately used to produce energy, and replenish energy stores as glycogen, is converted in the liver to fat. As the reservoir of this fat increases, it begins to circulate in the blood and starts clogging the highways and the byways of the circulatory system. Over time this could give rise to plaque, which may restrict blood flow, giving rise to high blood pressure, which may increase the risk of heart attack and stroke and may precipitate idiopathic Alzheimer's far ahead of time. The situation in individuals of advancing years may be complicated by the free radical load that the body cannot neutralize promptly and may trigger inflammatory responses. Of course Jonathan's case was aggravated by his lifestyle choices. He smoked heavily and cigarette smoke packs billions of free radicals in each puff. Consumption of large amounts of alcohol reduces the liver's ability to effectively detoxify the blood, which provides oxygen and nutrients to various tissues and organs. Toxins in the blood could potentially putrefy tissues and organs, which gradually may lose their function. As the blood thickens and cholesterol levels are elevated the circulation in the central nervous system is less than optimal. To an extent, that may explain Jonathan's worry about the lack of fresh ideas.

The brain function, however, is more complex than that. Jonathan's malaise may have been due to his outlook, which may be reflective of his poor health. Nonetheless a positive mindset does play a significant role in maintenance of good health. The more an individual is optimistic and less self-centered (as can be the case if one is frightened by one's state of health), the "idea density" decreases. That is, the proclivity to take mental challenges is reduced. This is complemented with the research findings in human aging research that good health and longevity go with "a twinkle in the eye." That is, good humor and recognition that one's health is stable are powerful weapons against the aging process.

Jonathan over the past few months has changed his lifestyle. He has taken control of his dietary habits, exercises regularly and has a strict regimen of healthy lifestyle habits. He reports that he has "never felt better in his entire life," which is quite likely a hyperbole, but he is demonstrably on the rebound. Jonathan's case underscores the point that dietary intervention can reset the biological age in individuals even with as severe symptoms as he first described to me. Jonathan will age chronologically, for that is inevitable. He will, however, decelerate the biological aging of his internal organs, which will over time heal his body, and he may yet enjoy good health for many years to come.

Of course sporadic and half-hearted adherence to this troika of sensible diet, regular exercise and healthy lifestyle cannot possibly restore internal health. Just as gradually the biological aging takes its toll on internal organs and viscera, so does the body recover equally slowly from the "abuse" of decades. The human body has immense ability to recover and thrive, largely because of the redundancy in its regulatory networks. The example of cigarette smoking may be quite instructive. It will take a habitual smoker 18 months after quitting smoking to come out of the danger zone of developing lung cancer, as determined by the American Lung Association. While it may be a long while, it reinforces the fact that the human body, given half a decent chance, will rebound, unless the damage is permanent.

As noted above, expansion of life span is the standing dream of mankind for millennia. Until a Methuselah gene in humans is identified and its ramifications for the aging process is thoroughly understood, life span cannot be increased indefinitely. In Greek mythology a story is told of Eos, the Goddess of the Dawn, who falls in love with a mortal, the Trojan prince Tithonus. She beseeches Zeus to grant her lover immortality and he does so. Eos forgets, however, to request eternal youth for him. Tithonus soon grows old, gray and crabby at the immutable goddess's side. Finally Zeus in his mercy turns him into a grasshopper, which sings the song of his love every morning through eternity with the coming of each dawn. The failure of this love story is due to asynchronicity in which timelessness and temporality have drifted apart. Immortality is no longer equivalent to eternal life but simply is the ability to live for eons. The promise of high technology, whether it is due to the much-touted telomerase therapy or human cloning, would first have to reconcile this asynchronicity. That is, the quantity of prolonged years must ensure their quality in terms of vitality and robustness. Until that comes to pass, attempts to age successfully is the best bet to harness the most of what life has to offer. Nutritional intervention alone is not likely to deliver the goods, unless it is combined with a rigorous regimen of sensible dietary habits, regular exercise and healthy lifestyle habits.

References:
(n1.) Ahmed, A. J. "Anti-Aging: The Elusive Mermaid," J. L Med. Assoc. N. Am. (1998). 30, 178.

(n2.) Ahmed, A. J. "Mammalian Cloning: Implications for Human Health and Aging," Intl. J. Anti-Aging Med. (1998). 1, 7.

(n3.) Rowe, J. and Kahn, R. "Human Aging: Usual and Successful," Science (1987). 237, 143.

(n4.) Schultz-Aellen, M. Aging and Human Longevity. Boston, Massachusetts (1997).

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By Aftab J. Ahmed, Ph.D.

Adapted by Ph.D.

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