DHEA

DHEA, which stands for dehydroepiandrosterone, is the most abundant hormone produced by the adrenal glands, and its production greatly exceeds that of all the other steroid hormones. The body produces DHEA in the early morning hours and then it declines fairly rapidly throughout the day, as it is quickly cleared by the kidneys. Small amounts of DHEA are also secreted by the ovaries and testes and, in fact, it serves as a precursor to the production of both testosterone and estrogen hormones.

Even before birth, DHEA is secreted by the human fetus. During childhood, usually at about ages 6-7 years old, substantial production of DHEA by the adrenals first begins, peaking at about age 20. Between the ages of 25 and 70 years, production steadily declines, and this is known to be the steepest decline of all the hormones in the endocrine system. The decline of DHEA is linear with increased age, leading some to regard these diminished levels as a biomarker for aging.

During pregnancy, the mother’s estriol levels rise as a result of the increased amount of DHEA from the fetus, a precursor to the mother’s estrogen production. As such, clinicians sometimes monitor estriol levels during the course of pregnancy to verify the status and continual growth and well-being of the fetus.

In general, the adrenal androgens (these are hormones that include DHEA and its derivatives) are of primary importance for testosterone status in women. In normal menstruating women, about 40% of their testosterone arises from the ovaries, while the remaining 60 percent comes from the conversion of DHEA produced in the adrenal glands. DHEA is also estimated to contribute 70% of estrogens before menopause and nearly 100 percent after menopause.

In men, on the other hand, where testosterone is the most important androgen, about 95 percent of their testosterone is produced in the testes; the remaining five percent is supplied by conversion of adrenal DHEA to testosterone.

Important Distinctions

When DHEA is metabolized, a sulfur group is added to the molecule and it is designated DHEA-S for DHEA sulfate. Over 90 percent of circulating DHEA is present in the sulfate form. DHEA-S is cleared from the body more slowly than DHEA, so blood levels of DHEA-S are fairly stable throughout the day. Because of the greater quantities of DHEA-S in the blood and the molecule’s relative stability, it is frequently recommended that the DHEA-S form be tested in the blood. However, this practice is not agreed upon by all clinicians and scientists studying DHEA.

Dr. Norman Shealy, the author of the book DHEA: The Youth and Health Hormone, cautions that there may not be adequate conversion to active DHEA from DHEA-S when it is needed. This concern was validated by a study reported in The Journal of Clinical Endocrinology & Metabolism, where the authors concluded that serum DHEA-S “is unlikely to reflect bioavailable DHEA.” Dr. Shealy recommends direct measurement of DHEA, which he believes is the most effective and fully active form of the hormone.

The Connection with Cortisol

Chronic stress leads to increases in cortisol, and with that, gradual depletion of DHEA. Over time, this hormonal imbalance can lead to hardening of the arteries, thinning bones, increasing waistline girth, and impaired functioning of the immune system.

High cortisol levels also lead to an increase in blood sugar. In response, more insulin needs to be secreted from the pancreas to clear the sugar from the blood and shepherd it into the cells. In chronic situations, alternating high and low blood sugar levels ensue. Eventually, the body becomes less sensitive to insulin. This phenomenon is commonly known as Metabolic Syndrome or Syndrome X. Several detrimental effects of this syndrome include weight gain and obesity, increases in cholesterol and triglyceride levels, and a rise in blood pressure. Adult-onset diabetes also may result.

Chronic high levels of cortisol may impair immune responses. The inability to fight infections leads to a higher susceptibility to colds and flu.

In the case of cancer, high cortisol levels interfere with the body’s capacity to fight cancer, and an increased likelihood of metastases may occur. Dramatic results have been obtained in animal studies when scientists have used DHEA against skin, lung, colon, breast, prostate, and lymphatic cancers.

The link between cortisol production and DHEA is an important one because, with long periods of chronically high cortisol levels, the ability to produce DHEA diminishes. For example, there is a link between a diminished circulating concentration of DHEA and the progression of immunosuppression and muscle loss in persons with AIDS. These patients also exhibit high cortisol levels.

One of the most significant effects of restoring DHEA seems to be the restoration of its normal balance with cortisol. As DHEA levels increase, the propensity to overproduce cortisol is dampened—along with the spiral of symptoms induced by high cortisol. In many of the health issues described in the following sections, you’ll note an important connection between DHEA and cortisol.

Aging

In humans, blood levels of DHEA are known to decline with age. Not surprisingly, this deficiency is associated with the development of various problems typical of aging, including decreased immune function, increased infections, and incidence of certain cancers, atherosclerosis, diabetes mellitus, and osteoporosis. Such observations have led to studies investigating whether DHEA can be used to achieve healthier aging or even to prolong life.

In their book Stopping the Clock, co-authors Dr. Ronald Klatz and Dr. Robert Goldman write, “It would seem logical that restoring DHEA levels would help to restore a biological condition of youth.”

Libido

Because testosterone is the major circulating androgen in men (as described previously), the impact of DHEA on the male libido may not be very important. In women, however, it is a major source of both estrogens and testosterone and might be expected to have a bigger influence on libido. The results of a 12-week study involving postmenopausal women who were given daily doses of DHEA intravaginally showed rapid and efficient improvements in sexual function and vaginal atrophy, without changes in their serum sex steroid levels.

Menopause

Given the link between DHEA and sex hormones, the role that it plays in menopause and its many symptoms have been examined, with interesting results. In one study of twenty postmenopausal women who took 25 mg DHEA daily for twelve months, the results were significant. These women showed progressive increases in their levels of testosterone, estradiol, estrone, progesterone, and growth hormone with corresponding improvements in symptoms.

Another study involving postmenopausal women, but with the administration to the skin, demonstrated a tendency to create more androgen than estrogens from DHEA, with the transformation effects diminishing with age. While more study clearly is required, Dr. Alan Gaby and others suggest that this may be an effective treatment for the undesirable symptoms associated with menopause.

Osteoporosis

Deterioration and thinning of the bones is a hallmark of osteoporosis. A major cause of bone thinning may be the unrelenting levels of high cortisol induced by stress— perhaps because it depletes DHEA. By restoring balance, this detrimental effect on bones may be forestalled. Additionally, as a precursor to both testosterone and estrogens, DHEA can help supply the hormones needed to both stimulate new bone-cell formation and break down old bone. A 15-year study suggests that bone mineral density may be directly related to circulating DHEA levels.

Cardiac Health

Because declining DHEA levels seem to correlate with an increased incidence of heart disease, scientists are interested in determining how this hormone might be cardioprotective. For instance, DHEA supplementation seems to decrease the rate of platelet aggregation (formation of blood clots), which could lead to fewer cases of stroke.

Heart disease is also linked in part to increased inflammation, which involves numerous molecules called cytokines. DHEA lowers two of the cytokines that stimulate the inflammatory process, sometimes even to the point of attacking healthy tissue. It also appears that DHEA has an antioxidant effect and may lower LDL cholesterol, thereby protecting the arteries.

Aging Skin

As we age, our skin thins and is more inclined to wrinkle and crease. The aging process is also characterized by the production of skin enzymes that break down collagen. Collagen is critical for the normal support of the skin’s structure, and it appears that DHEA helps maintain collagen levels. DHEA supplementation increases the color, tone, thickness, and hydration of the skin.

Dry Eye Syndrome

Another downside of aging is the increased incidence of dry eye syndrome, a condition that causes irritated, red, and itchy eyes. The syndrome seems to be more prevalent in women, especially once they start perimenopause.

One antidote for dry eyes is the use of over-the-counter or prescription eye drops designed to lubricate eyes. However, these artificial tears often fail to provide relief because they lack some of the natural lipids produced by specialized sebaceous glands in the eye. Because it has been shown to stimulate sebaceous glands, an eyedrop containing DHEA was developed and used to treat women suffering from dry eye syndrome. These women reported less eye irritation and the improved production of natural tears.

Depression

DHEA is also believed to significantly improve mood and emotional stability. In his book, Dr. Shealy remarks “We have never seen a depressed patient with optimal levels of DHEA. And no one we’ve seen with optimal levels of DHEA is depressed.”

A study in England confirmed his observation by demonstrating that the lower the levels of DHEA in a group of depressed patients, the more severe their depression. The patients with low DHEA levels also exhibited high cortisol levels.

Memory and Cognition

It is well accepted that cognitive function—which includes memory, reaction time, and learning ability— may progressively decline as we age. This decline is linked to high cortisol levels, which damage neural cells in the brain. DHEA shows great promise as it appears to protect the brain from the damage induced by high cortisol levels.

Conclusion

Given what we now know, we may want to start paying more attention to DHEA levels because they relate to so many aspects of our overall health. For starters, reducing stress in our lives can improve DHEA levels naturally. Drinking a cup of coffee each morning may boost levels because of a link to caffeine. On the other hand, taking oral contraceptives lowers these levels; so alternative forms of birth control may be a consideration. Finally, as with other bioidentical hormone therapies, DHEA levels can be improved by supplementation. However, it is important to check with a healthcare practitioner for evaluation and guidance for adequate dosing before trying any supplementation.

This amazing hormone has proven to be highly versatile and intimately involved with our ability to thrive and survive. With ongoing research, and medical practitioners continuing to use and monitor DHEA in their patient practices, we will continue to learn more about the role of this important hormone and its potential effects on many aspects of our general health.