What are the factors that really affect our lifespan? Pollution, bad food, lack of exercise and obesity are all familiar culprits. Endocrine disorders such as the decrease of serum levels of testosterone, DHT, melatonin, DHEA, the thyroid hormones, growth hormone, IGF-1 and progesterone produce a spectrum of age-related conditions including diabetes, hyperlipidemia, thyroid deficiency, depression and obesity? In addition, pollutants in the environment can create estrogen-like effects, resulting in diminished levels of androgens. Interventions such as hormone replacement therapies may favorably influence some of the pathological changes of aging, but the foods we choose to eat are even more important in preventing age-related deterioration.ÝThe heavy ingestion of animal products may be responsible for the epidemic of ìwesternî cancers. Diet and cancer have been inextricably linked through research into dioxin, PCBs, nitrites, high cholesterol, trans fats and the low fiber American diet. The aging process is much more complex than simple hormonal deficiencies and evidence is presented that the average lifespan can be altered by dietary lifestyle changes including vegetarianism. Ý

What Really Affects Aging?

The desire to remain young is as old as mankind. But what are the factors that really affect our lifespan? In discussing aging, we must consider two definitions of lifespan. Average lifespan-- the average age at which members of our species die, (75 to 85 yrs) and maximal lifespan-- the age achieved by the longest-lived human. (122 yrs) Improvement in average lifespan can be achieved by assuring a clean food and water supply, vaccinations, and other preventive measures, but lengthening the maximal lifespan is much more difficult than increasing the average lifespan.

At the close of this millennium there were about 77,000 people one hundred years and older in the US, and statisticians predict that the number of these centenarians is expected to double with each decade for the foreseeable future. So did these ìMethuselahî patients simply have long-lived relatives and healthy families? Not necessarily! Most long-lived people refrained from the regular use of alcohol and tobacco. But even if we assume for a moment that lucky genes are the sole reason for a long and healthy life, you still cannot choose your relatives.

Through the decoding of the human genome early in 2003, mankind has come a step closer to determining some of the genetic factors that may one day unlock the secrets of the aging process. At the same time the world population is expanding rapidly; life expectancy is increasing, and fertility rates are decreasing (a decrease of 45% over the past two decades). The resulting increases in population growth will occur largely among the aging population.

Even prior to the days of genetic manipulation, we are already living longer than our forefathers. The elderly population is growing so fast that soon theyíll be in the majority. New forecasts project that halfway through the twenty-first century the median life expectancy will surpass previous estimates by up to 8.0 years. (1)

Anti-Aging Products

Thousands of products and treatments are offered today to slow the aging process. Costly anti-aging medications have emerged in the marketplace to give people the illusion that they can buy longevity, if they have enough money. For example many seniors are led to believe that by injecting themselves every day with a human-like growth hormone, they will enjoy longer life. Do these therapies work? Are the over-the-counter or OTC hormones another cruel hoax thrust upon an unwary population looking for a shortcut to a longer and healthier life?

The aura surrounding human growth hormone (HGH) and its apparent anti-aging activity is a classic example of how unscrupulous marketers mix greed, misinformation, and exaggerated claims. Nasal sprays, pills and oral homeopathic HGH products are but a few examples of what the anti-aging market has to offer. Endocrinologists should also be quite cautious in treating every patient who visits their offices looking for a reversal of aging with growth hormone.

It is true that the aging process produces endocrine alterations that involve both reduced output as well as decreased responsiveness of the central regulating mechanisms in the brain. These factors produce the age-dependent decrease of the peripheral levels of testosterone, DHT, DHEA or dehydroepiandrosterone, the thyroid hormones, growth hormone (GH), IGF-1 and melatonin.

While the aging process produces endocrine deficiency, there is no proof that correcting these deficiencies or buying some of these hormones OTC will reverse aging. We should each question whether these hormonal decreases result from "natural" causes, disease or are due to increasing environmental pollution. We all remember what happened to the theory that hormone replacement therapy (HRT) would keep women ìforever youngî. The outcome of supplementing most post menopausal women with synthetic estrogen and progesterone was an acceleration of thromboembolism, an increase in Alzheimerís and cardiovascular disease, in addition to the increased incidence of certain hormone-dependent cancers.

Environmental Diseases

The contribution of environmental toxins to cancer growth should be considered. Environmental toxins have the ability to alter both our DNA and our hormones. Over the past 30 years, researchers have discovered that DDT, PCBs, PVCs and dioxins were depositing in human fat and breast milk. Dioxin, present in most pesticides and plastics, has become the most toxic and deadly compound known to man. Everywhere on the planet, hundred of similar industrial chemicals called organochlorines are accumulating within our bodies and entering our food chain.

These chemicals mimic the action of certain hormones creating multiple chronic conditions often associated with aging (e.g. diabetes, obesity, hypothyroidism, hyperlipidemia, arthritis, and sexual dysfunction.) Theo Colborn, known as the Rachel Carson of the '90's, stated in her book Our Stolen Future, " Humans carry PCBs and other persistent chemicals in their body fat, and they pass this chemical legacy on to their babies. (3)

If we already have high enough levels of these toxic chemicals in our body to affect our reproductive function, what can we do to protect our childrenís health and their future fertility? If our drinking water is tainted with antibiotics, oral contraceptives and hormone disrupters should we monitor our water supply? Could this be a reason why are we seeing more hormonal imbalances in our patients?

Androgen Replacement as a Treatment for Aging

As a consequence of these premature hormonal deficiencies, pharmaceutical companies are currently promoting the use of androgens, to restore both men and womenís ìget up and goî. Androgen replacement therapy, (ART), a relatively new approach to improving lifespan, has been found medically effective in the past in multiple conditions including anemia, wasting diseases such as cancer or AIDS, and in treating impotence, low testosterone and prostate enlargement. But does ART prolong life or increase our lifespan?

Those hormonal changes, which develop in most men at about the age of 50, are in part, responsible for a condition called late-onset hypogonadism. This is a syndrome characterized by detrimental effects on multiple organ systems leading to a decreased quality of life in both sexes, associated with advancing age and characterized by the following signs and symptoms including: diminished sex drive and frequency of morning erections, depression and memory loss, decreased muscle mass and increased weight.

In cases of hormonal deficiencies, hormone replacement may favorably influence some of the pathological conditions in aging men by ìpreventing the preventable and delaying the inevitable,î according to the Israeli researcher, Bruno Lunenfeld. (1)

In the era of evidence-based medicine, we have to acknowledge that data on testosterone replacement therapy (TRT) in the aging male is still mostly circumstantial, based on experience in the treatment of temporary or chronic hypogonadism in young men resulting from diseases or experiments with self- medication with anabolic steroids.

The popular press reports that American men may be experiencing an epidemic of hypogonadism. Regardless, a comprehensive medical, psychosocial and lifestyle history, a physical examination and laboratory testing are essential for the diagnosis and management of hypogonadism. TRT is totally safe when monitored by a physician. Screening tests for deficiency are inexpensive and relatively accurate. Numerous clinical trials using testosterone therapy in the aging male have been shown to be beneficial for certain older men in preventing or delaying some aspects of aging. (2)

Is there a ìdo-it-yourselfî way to extend our years? For several decades caloric restriction has been touted as a means of reaching maximal lifespan. Researchers describe the miraculous doubling and tripling of lifespan in certain animals and insects, but what happens in humans? Is it restricting calories, hormones, lifestyle, or exercise that makes some people age better than others? The answer may surprise you. ÖÖÖÖ

Nutrition and Longevity

Intuitively we know that food is essential for life. Yet today, babiesí first nourishment, the breast milk of their mothers in every industrialized country contains dioxin residues beyond levels acceptable as ìsafeî, yet vegetarian mothers have less than 2% of the dioxin level of other women.

The shocking reality is that food has become contaminated with environmental poisons: PCBs from plastics, electronics, fluorescent lights and incinerator fumes. These chemicals are now part of the fabric of our daily lives. Letís not forget heavy metals like mercury, cadmium and lead which circle the globe in dust clouds, ending up in the very air we breathe. Organochlorines may damage our atmosphere, depleting our protective ozone layer. Still the most deadly poisons invade our bodies through the food we eat.

ìGood nutrition, could be the most important reason why some of us get along better than others in our advancing years.î

But there is more. The foods you choose to eat are as important in preventing disease as how much you eat. When tofu was substituted for lean meat in two groups of men, while various hormone levels were measured, the meat group had a 10% higher testosterone/estrogen ratio (T/E2); sex hormone binding globulin or SHBG was 3% higher as compared to the tofu group (which had 8.8% higher SHBG and significantly lower T/E2 ratios). The diets provided an equivalent amount of macronutrients including calories. This Australian crossover study demonstrated that diet has an effect on biologically active sex hormones, and could subsequently influence both testosterone and prostate cancer risk. Many doctors still think that testosterone causes prostate cancer, which is much lower in Asian men. (4)

Another report compared vegans (who eat no animal products) and omnivores (who eat everything) and found that there was a substantial increase in SHBG. If you recall, SHBG acts as an ìon-offî switch for freeing up testosterone both peripherally and in the brain. (5) This finding was confirmed in younger vegetarians versus non-vegetarians. The conclusion from various respected researchers is that our diet does alter the production and metabolism of steroids in men and women, possibly by making less testosterone available for androgenic action. (6) Food definitely affects our hormones.

The content of our diet obviously changes our weight. Fish-eaters, vegetarians and particularly vegans had lower BMIs (Body mass index-- the relationship between height and weight) than meat-eaters. (7) Non-meat eaters, especially vegans, also have a lower rate of hypertension, better diabetes control and lower blood pressures than meat eaters, largely because of differences in weight. (8) A high BMI is now considered a predictable risk factor for heart disease and diabetes.

What can the average American do? Weight loss and dietary lifestyle changes are a good place to start. In clinical studies, vegans have even higher testosterone levels than vegetarians and meat-eaters, but this is offset by higher SHBG. Yet low-fat vegan diets are especially protective in regard to cancers linked to insulin resistanceónamely, breast and colon canceróas well as prostate cancer. A plant-based (vegan) diet is also associated with a lower circulating level of insulin-like growth factor (IGF-I) compared to a meat eating or a lacto-ovo-vegetarian diet. (9)
In fact, vegans tend to have low cholesterol, leaner physiques, later puberty, and a decreased risk for some cancers. Low-fat vegan diets coupled with exercise training also tend to improve diabetic control and lower elevated blood pressures. In other words, ìFood affects our hormonal balance.î
(11, 12)

Diet and the Cancer Controversy

Conversely, some researchers state that high IGF-I (as induced by HGH supplementation) may be largely responsible for the epidemic of certain cancers in Western societies. (10, 4, 13) Diet and cancer have been inextricably linked through research into TCDD, PCBs, nitrites, high cholesterol, trans fats and the low fiber American diet. (13) Eating organically grown foods while following a plant-based diet not only improves our average lifespan but may also prevent infertility, decreases diabetes and cancer risk by changing the balance of our hormones. (14, 15,16)

Organic foods give us a choice as to how many chemicals we consume and what we feed our children. Organic food, including meat raised without pesticides or hormones is widely available in American supermarkets and specialty stores. It does cost a bit more but our health and that of our children should be much more important than the small extra cost of buying organic products. (17)

Today, the promotion of health and longevity as they relate to our environment is becoming a priority of our government. Unfortunately, cost cutting to deliver higher profits is really what drives our current health care system. Our medical system does not deliver health; instead a lifetime of costly medical care is the true product. Research has given us the tools to prevent and treat premature hormonal deficiency and obesity, yet toxic environmental compounds such as dioxin and synthetic estrogens are ubiquitous, upsetting the hormonal balance of millions of men and women. (18) It is crucial that we, as physicians, educate our patients about the dangers of environmental pollution and their effects on fertility. (19, 20)

Misconceptions are plentiful regarding a healthy diet, or what constitutes normal aging and what is a sign of disease. We all know that aging is much more complex than a simple hormonal deficiency or calorie restriction. Our quality of life can be improved considerably by listening to our bodies and educating the public about preventing weight gain and the consumption of toxins in our food chain. Discussing our patientsí nutrition, fertility and sexual function plus the benefits of eating organic foods to avoid pesticides, delivering appropriate vaccinations, encouraging exercise regimens and teaching stress reduction are the best preventive medicine for a long and healthy life.

References:

1. Lunenfeld, B. (2003) Androgen therapy in the aging male. World J Urology. Nov;21(5):292-305. Epub 2003 Oct 24.

2. Hermann, M. and Berger, P. (2001) Hormonal changes in aging men: a therapeutic indication? Exp Gerontol. Jul;36(7):1075-82.
3. Colborn, T. et al. (1997) Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival? Plume Book

4. Habito, R.C. et al. (2000) Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males. . Br J Nutr. Oct;84(4):557-63.

5. Key, T.J. et al.(1990) Testosterone, sex hormone-binding globulin, calculated free testosterone, and oestradiol in male vegans and omnivores. Br J Nutr. Jul;64(1):111-9.

6. Belagner, A. et al. (1989) Influence of diet on plasma steroids and sex hormone-binding globulin levels in adult men. J Steroid Biochem. Jun;32(6):829-33.

7. Spencer, E.A. et al. (2003). Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans. Int J Obes Relat Metab Disord. Jun;27(6):728-34.

8. Appleby, P.N. et al. (2002) Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC-Oxford. Public Health Nutr. Oct;5(5):645-54.

9. Allen, N.E. et al. (2002) The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer Epidemiol Biomarkers Prev. Nov;11(11):1441-8.

10. Allen, N.E et al. (2000). Hormones and diet: low insulin-like growth factor-I but normal bioavailable androgens in vegan men. Br J Cancer.Jul;83(1):95-7.

11. McCarthy, M.F. (1999) Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity. Med Hypotheses. Dec;53(6):459-85.

12. Kryger, AH. (2004) Listen To Your Hormones: A Doctorís Guide To Sex, Love and Long Life. WellnessMD Publications. HYPERLINK "mailto:DrK@wellnessmd.com" DrK@wellnessmd.com

13.Murray, T.J. et al. (2001) Endocrine-disrupting chemicals: Effects on human male reproductive health. Early Pregnancy Apr;5(2):80-112

14.Feeley, M. and Brouwer, A. (2000) Health risks to infants from exposure to PCBs,
PCDDs and PCDFs. Bureau of Chemical Safety, Banting ResearchÝÝ Centre,
Health Canada, Ottawa, Ontario, Canada. HYPERLINK "mailto:mark-feeley@hc-sc.gc.ca" mark-feeley@hc-sc.gc.ca .Food Addit
Contam 2000 Apr;17(4):325-33.

15. Roberts J. (1994) US Scientists class dioxins as a health concern. BMJ
Sep 24;309(6957):759-760

16. Sweeney MH, Mocarelli P. Human health effects after exposure to
2,3,7,8-TCDD. Food Addit Contam 2000 Apr;17(4):303-16. National Institute
for Occupational Safety and Health, Education and Information Division,
Cincinatti, OH 45226-1988, USA. HYPERLINK "mailto:mhs2@cdc.gov" mhs2@cdc.gov

17. Calvert GM, Sweeney MH, Deddens J, Wall DK. Evaluation of diabetes mellitus, serum glucose, and thyroid function among United States workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin. Occup Environ Med Apr;56(4):270-6

18. Egeland GM, et al. (1994) Total Serum Testosteronre and Gonadotropins in Workers Exposed to Dioxin.ÝÝAm J Epidem; 139 (3): 272-81.

19. Ministry of Environment and Energy, Denmark.(1995) Male reproductive health and environmental chemicals with estrogenic effect. Miljoprojekt no. 290. Copenhagen: Danish Environmental Protection Agency