General Description
DHEA is a steroid hormone produced by the adrenal glands. Often
called "the mother steroid" because it can be converted into testosterone
and estrogen, DHEA circulates throughout the body in the bloodstream,
primarily in the sulfated form DHEA-S. DHEA is the most abundantly
produced adrenal steroid. Serum concentrations of DHEA-S are approximately
20 times higher than those of any other steroid hormone.1
The body's ability to produce DHEA declines with age, with peak
serum DHEA and DHEA-S levels occurring around age 25 and decreasing
thereafter. By age 90, DHEA levels in the body are roughly 5% of
what they were at their peak. Although the physiological role of
DHEA is unknown, many scientists believe the decline of DHEA production
by the adrenals may contribute to the physical and mental deterioration
associated with aging. Synthetic DHEA is available in capsule form,
most commonly in 10, 25, and 50 mg sizes. DHEA may also be purchased
in creams, ointments, and lozenges.2
Health applications
Cardiovascular health
Several studies have examined DHEA's potential role in the prevention
of cardiovascular disease. Studies indicate that low DHEA levels
are associated with increased risk for cardiovascular disease
in men, but this association has not been demonstrated in women.3-6
DHEA appears to exert a favorable influence on the serum lipid
profile in men, reducing total cholesterol and LDL levels, while
improving HDL/LDL ratios. 1, 7-9 Research
also indicates that DHEA exerts antioxidant activity, inhibiting
the oxidation of LDL (a major contributor to atherosclerosis).9
Other studies show that DHEA inhibits the clumping together of
blood platelets, promoting healthy blood flow.10
DHEA and aging
The role of DHEA in the aging process has been much debated, with
proponents of DHEA replacement speculating that restoration of
youthful levels of the hormone may counteract many of the degenerative
effects of aging. Some studies have shown increase in perceived
physical and physiological well-being in men and women who restored
DHEA levels to those found in young adults. 11
Other studies on DHEA replacement showed improvement in lean muscle
mass, immune function, and perceived quality of life in aging
men and women.12 Low plasma levels of DHEA
have been linked to many conditions associated with aging, including
Alzheimer's disease and other forms of age-related cognitive decline.13-16
Immune system support
Preliminary research indicates that DHEA may play an important
role in immune system function. One study showed that supplementing
DHEA can improve immune function in advanced-age men with low
DHEA levels.17 Studies conducted on laboratory
mice showed DHEA improved their resistance to bacterial and retroviral
infection.18,19 Studies using human tissue
indicate DHEA may improve natural killer cell activity. 20,21
Low serum concentrations of DHEA are associated with a variety
of medical conditions including AIDS,22 inflammatory
bowel disease,23 chronic fatigue syndrome,24
lupus,25-27 erectile dysfunction,28
and depression.29,30
Dosage/toxicity
Although there is no known toxicity for DHEA, safe daily intake
levels vary with the hormonal profile of the individual. Long-term
evidence of safety is lacking. Because DHEA supplements can increase
levels of certain male and female hormones, some scientists believe
excess DHEA consumption may contribute to certain hormone-dependent
cancers. For this reason, it is recommended that DHEA only be
supplemented by people with low levels of the hormone, and only
under the supervision of a physician who can monitor hormonal
changes. Side-effects associated with elevated DHEA levels include
acne, growth of excess facial hair and deepening of the voice
in women, overstimulation or insomnia, and fatigue. These effects
are generally seen in higher doses (over 50 mg) and are uncommon
at lower doses (5 to 25 mg).2 |
