How Do We Age
Science has long puzzled about what causes the wrinkles, pains and deterioration of aging. In the search for causes, two basic theories have won over the most proponents: The first holds that cells are programmed with biological clocks that predetermine how many times they can reproduce before becoming non-functional. This theory has been largely formulated by the researcher Leonard Hayflick, MD.

The second basic theory, introduced by Denham Harman, MD, PhD, in the mid 1950s, holds that cells eventually break down due to attack by caustic molecules called free radicals that cause oxidative stress.

Programmed Cell Theory
In the early '60s, Dr. Hayflick observed that human fibroblasts (cells from connective tissue) in the laboratory refused to divide more than about 50 times. Dr. Hayflick also found that even if he froze the fibroblasts after 20 divisions, they would remember that they only had 30 divisions left after thawing.

Fifty cell divisions have been called the "Hayflick limit." Based on this research, scientists theorize that cells maintain a genetic clock that winds down as old age ensues. Many researchers believe the hypothalamus gland is the force behind our aging clocks, signaling the pituitary gland to release hormones that cause aging.

Free Radical/Oxidative Stress Theory
The other popular theory of aging pictures the human body as a cellular battlefield where attackers called free radicals damage our cells and tissues, making them age. In this scenario, a process called oxidation is the chief aging villain.
On a microscopic level, oxidation generally entails molecules or atoms losing electrons. (Gaining electrons is called reduction.) The molecules or atoms that take these electrons are oxidizing agents.

Free radicals are substances that can exist with missing electrons, making them readily able to donate or accept electrons and damage structures in cells. As such, they are highly reactive, binding with and destroying important cellular compounds. Most of the free radicals in your body are made during metabolic processes. More are added from the food you eat and environmental pollution.
Most of these free radicals contain oxygen molecules. As each cell makes energy in little structures called mitochondria, free radicals result. These oxidant by-products can damage DNA, proteins and lipids (fats). Consequently, toxic by-products of lipid peroxidation may cause cancer, inhibit enzyme activity and produce mutations in genetic material that make you age faster.

DNA Repair Theory
Free radical damage to DNA can cause cells to mutate or die. Your body makes enzymes that can repair this damage and slow aging. But, over time, the amount of damage overwhelms the body's ability to fix things. As cells grow older, their ability to patch up DNA diminishes and the rate of damage proceeds faster than repair. The result: We age and eventually die.

What Can We Do
The free radical theory of aging suggests that taking antioxidants (compounds known to prevent free radical damage) in our food or as supplements may slow aging.

In the publication Age (18 [51] 1995: 62), it was reported that "aging appears to be caused by free radicals initiated by the mitochondria at an increasing rate with age. Superoxide and hydrogen peroxide radicals formed by the mitochondria during normal metabolism are major risk factors for disease and death after about the age of 28 in developed countries. Antioxidants from the diet lower the production of free radicals without impairing essential reactions to maintain body function."

Antioxidant Protection
Common dietary antioxidants include: vitamins E and C, carotenes, sulphur containing amino acids, co-enzyme Q10 and flavonoids (a group of plant compounds or pigments responsible for the color in fruits and flowers). In addition, melatonin, DHEA and the amino acid compound glutathione may also prove of benefit.

Glutathione along with the enzyme glutathione peroxidase are an essential part of free radical "quenching." (Quenching means changing free radicals into benign substances no longer capable of harm.) Deficiencies may suggest a decreased capacity to maintain detoxification and metabolic reactions in which glutathione plays a role, resulting in increased free radical stress and/or lipid peroxidation. Drinking too many alcoholic beverages can result in glutathione deficiency.

In a study in which 39 healthy men and 130 healthy women between the ages of 20 and 94 were evaluated for glutathione levels, the older subjects had significantly decreased levels (especially in the 60 to 79-year-old group). The authors felt that physical health and longevity were closely related to glutathione levels (Jrnl Lab & Clin Sci 120(5), Nov. 1992: 720-725).
Poor nutrition and/or deficiencies in essential micronutrients and many prescription medications may contribute significantly to detoxification capacity in an aged individual. All of these circumstances are common in the elderly.

Eating a poor diet that contains too many processed foods without many fruits and vegetables can compromise your body's ability to detoxify pollutants, toxins and other harmful compounds. That can set off metabolic processes capable of fomenting large increases in free radical stress that can accelerate aging. Unfortunately, even in a country as prosperous as our own, nutrient deficiencies are frequent, especially in older citizens.

Nutrition Deficiencies
A study that looked at what elderly people consumed compared their reported intake with the 1989 Recommended Dietary Amount (RDA) and 1980 RDA: One of four people consumed only two-thirds of the RDA for calories and 60% consumed less than two-thirds of the RDA for vitamin D. As for other nutrients, 50% were found to have inadequate zinc levels (less than two-thirds of the RDA), 31% lacked calcium, 27% were short of vitamin B6, 25% didn't get enough magnesium, 7% missed out on folate and 6% ate less than two-thirds of the requirement for vitamin C (Nutrition Reviews (II), September 1995: S9-S15).

When researchers examine what everyone in the U.S. eats, they find that only 9% of Americans consume the recommended five servings of fruits and/or vegetables per day (Proceedings of the National Academy of Sciences, Sept 1993).

A diet high in fruits and vegetables is naturally high in antioxidant compounds and is believed to help you live longer. Unfortunately, if you buy your produce in the supermarket, those fruits and vegetables may also be rich in pesticide and herbicide residues (Consumer Reports, March 1999). Obviously, organic produce lacks these residues. But, in any case, research continues to indicate that a diet low in meats and animal fat and high in vegetables protects against antioxidant damage.

Longevity Diets
A six-year study of 182 people over age 70 in rural Greek villages found that those following their traditional diet of olive oil, whole grain breads, fresh fruits and vegetables and wine were less likely to die during the study than those who consumed more red meat and saturated fat. The most important foods in lowering the risk of early death included fruits, vegetables, legumes (peas and beans), nuts, dairy products and cereals (BMJ 311, 1995: 1457-1460).

Another article in Epidemiology highlights the evidence that eating a vegetarian diet increases your chances of living longer. Included in this survey is a recent country-wide study of diet and health in China, showing that the traditional near vegetarian diet of 10% to 15% of calories coming from dietary fat reduced the chances of heart disease, diabetes and many types of cancers (Epidemiology 3[5], 1992: 389-391).

Staying Alive
Staying skinny and limiting what you eat may also increase longevity. Scientific studies have previously shown that being overweight can theoretically curtail your life, increasing the risk of heart disease, diabetes and other life-shortening conditions. Animal studies have also shown that restricting food can slow diseases associated with aging.
Researchers believe that cutting calories helps your immune system stay younger by reducing the formation of substances that are called proinflammatory cytokines.

Specifically reducing your intake of fatty foods may decrease your chance of coming down with autoimmune diseases. Researchers think omega-6 fatty acid vegetable oils (like corn oil) may increase free radical formation and decrease levels of antioxidant enzyme messenger RNA in addition to other effects (Nutrition Reviews 53[4], 1995: S72-S79). Another study found that cutting calories lowers the levels of oxidative stress and damage, retards age-associated changes and extends maximum life span in mammals (Science 273, July 5, 1996: 59-63).

In yet another study, it was shown that caloric restriction early in the life of lab animals increased their life span by a whopping 40% (Australian Family Physician 23[7], July 1994: 1297-1305). Today's modern higher-fat, low-fiber diet with substantial sugar consumption represents everything the longevity researchers say you shouldn't eat.

Longevity and Exercise
Exercise may slow aging. When researchers looked at the exercise habits of 17,000 men, average age of 46, they found that those who took part in vigorous activity lived longer.

Exercise can improve both cardiac and metabolic functions within the body, while also decreasing heart disease risk. Even modest exercise has been shown to improve cholesterol and blood sugar levels (JAMA 273[15], April 19, 1995: 1179-1184). In a study of how exercise affects your chances of living longer, 9,773 men underwent preventive medicine examinations on two different occasions. When the researchers looked at who lived longest, they found the highest death rate was in men who were unfit during both physical exams.

The Treadmill of Life
The lowest death rate was in the men who worked out and were in good shape. The researchers concluded that for each minute increase in how long a man could keep treading on a treadmill (between the first and second exam) there was a corresponding 7.9% decrease in the risk of dying (JAMA 273 [14], April 12, 1995: 1093-1098).

Since exercise can increase oxygen consumption up to 10 times, boosting the rate of production of free radicals, researchers believe that older individuals need more antioxidant nutrients to protect them. In a paper published in Aging Clinical and Experimental Research (1997), researchers stated that if you regularly exercise in your golden years, you should take more antioxidant vitamins to compensate for this risk.

Longevity Supplementation
Melatonin is not often thought of as an antioxidant, but, instead, as a sleep aid. Melatonin, however, is an effective and efficient free radical scavenger and may help stave off the effects of aging. Melatonin protects against what are called hydroxyl free radicals. Research shows that older people's lack of melatonin may make them more susceptible to oxidative stress. In one study, researchers felt that new therapies aimed at stimulating melatonin synthesis may eventually lead to therapies for the prevention of diseases related to premature aging (Aging and Clinical Experimental Research 7[5], 1995: 338-339). Melatonin was shown to provide antioxidant protection in several ways.

Toning Down Enzymes
Melatonin can ease the effects of enzymes that generate free radicals, enhance the production of glutathione peroxidase (an antioxidant) and defuse the caustic action of free radicals that contain hydroxyls.
In several studies, DHEA supplementation has been shown to potentially revive immune function in older adults (Exp. Opin. Invest. Drugs 4[2], 1995: 147-154).

In a study of 138 persons older than 85 years compared to 64 persons 20 to 40 years of age, scientists found that the younger people had four times as much DHEA in their bodies.

The researchers believe that our bodies make less and less DHEA as we get older. The authors of this study raise the possibility that declining DHEA may be partly to blame for our biological clocks running down (New York Academy of Sciences 1994: 543-552).

Vitamins E & C
A growing body of research also supports the benefits of taking vitamins E and C to hold off the effects of getting old. Researchers writing in Free Radicals and Aging (1992: 411-418) point out that as you get older your body is home to more and more free radical reactions that may lead to degenerative diseases like heart disease and arthritis. Research has found that in older people with exercise-induced oxidative stress, taking vitamin E every day may significantly fight off free radicals. (To investigate this effect, scientists measured waste products in urine that result from free radical reactions.) Their conclusion: Dietary antioxidants such as vitamin E may be beneficial.

Chronological Age Vs.Biological Age
Vitamin C also looks to scientists like a good anti-aging bet. Research in the Journal of Advancement in Medicine, (7[1], Spring 1994: 31-41) showed that folks consuming larger amounts of vitamin C were less likely to experience clinical problems at all ages. Those taking in less than 100 mg of vitamin C per day also suffered the most problems.

In this research, individuals over 50 years of age who daily consumed the largest amount of vitamin C were as healthy or healthier than the 40 year olds who were taking the least amount of vitamin C.

Similar Relationship
A similar relationship appears to exist for vitamin E and serum cholesterol levels. In a study of 360 physicians and their spouses, researchers found that people in their 50s who consumed more vitamin E had lower cholesterol than those in their 30s who were taking less.

And the longevity beat goes on: In a study evaluating environmental tobacco smoke and oxidative stress, researchers divided 103 people into three groups. Researchers blew smoke at 37 of these folks without protection while 30 of them got to breathe tobacco smoke but took antioxidant supplementation. Another 36 of them merely had to read magazines from doctors' offices. The results: After 60 days of supplementation the antioxidant folks had a 62% reduction in evidence of oxidative damage to their DNA. Cholesterol levels dropped and so did antioxidant enzyme activities. The researchers concluded that taking antioxidants provided a modicum of protection against environmental poisons.

The range of antioxidant nutrients used in this study included: beta-carotene, vitamin C, vitamin E, zinc and selenium as well as copper (Cancer Epidemiol Biomarkers Prev 7, November 1998: 981-988).

Carotenoids
When you mention carotene or carotenoids, most people think of the beta carotene that makes carrots orange. But more than 600 carotenoids are present in colorful vegetables and many of these misunderstood substances are more potent antioxidants than beta-carotene.

Carotenoids have been shown to destroy oxygen free radicals in lipids (fats), help protect our cells from the sun's ultra violet radiation and enhance our natural immune response (J. Nutr 119[1], Jan. 1989: 112-115).

Some evidence seems to show that how much carotenoids you (and other mammals) have in your cells may be the predominant factor in determining life span (Proc Natl Acad Sci 82 [4], 1985: 798-802). Therefore, a diet rich in carotenoids (leafy green vegetables, carrots, yams, sweet potatoes, squash, citrus fruits and tomatoes) along with supplementation seems to be just what the fountain of youth ordered.

Flavonoids
Flavonoids, a group of antioxidant plant pigments, seem to be able to protect specific organs.
For instance, the flavonoids in milk thistle (Silybum marianum) have been used for ages for liver problems. Bilberry has been found protective for the eye and hawthorn for the heart and circulatory system.

Numerous studies have shown the many beneficial effects of flavonoids with perhaps the best known being the ability of anthocyanidins in wine and grape seed extract to help protect your blood vessels and capillaries from oxidative damage (Phytotherapy 42, 1986: 11-14; Am J Clin Nutr 61, 1995: 549-54).

Flavonoids are found in vegetables and such fruits as blackberries, blueberries, cherries and grapes. A diet rich in these foods helps ensure an adequate intake of these important nutrient compounds.

Amino Acid Health
Methionine and cysteine are sulphur containing amino acids (protein building blocks), both of which are essential in maintaining levels of glutathione, a substance that plays a major role in quelling free radicals. Studies have found that as we age, the level of these important amino acids in our bodies decreases. (NEJM 312 [1], 1985: 159-68).
As it has been shown that adding cysteine to the diet of test animals can increase their life expectancy considerably, researchers believe these amino acids can help us live longer too.

Attitude & Behavior
Get more sleep! A recent study showed that men who habitually napped were less likely to have a heart attack. The men in this research who regularly napped for at least 30 minutes per day had about a 30% reduction in heart problems while those who napped for a full hour had a 50% reduction compared to non nappers. Naps of longer duration did not seem to increase the benefit.
In the same research, investigators also found that spending time with a pet or merely contemplating nature could also improve cardiac health. Sensuality, optimism and altruism also appeared to have health benefits (Family Practice News, December 15, 1998: 14-15).

In another study, this one in American Psychologist, researchers from the University of California found that people who are self-indulgent, pampered and achieve by running roughshod over the competition are less likely to outlive their healthy peers. Being egocentric, impulsive, undependable and tough-minded were predictors of poor physical health and a shorter life. So loosen up and be nice to your fellow humans! (U.C. Davis Magazine, Fall 1995: 14).

Longevity at Last
While no one has suggested that taking supplements, eating vegetables or exercising can, as of yet, extend the human life span past the generally recognized limit of about 120 years, researchers believe they can improve your odds of longer life. And by staying healthier, your old age will be more enjoyable, too.