DHEA and Cancer
Early reports from England [Bulbrook, 1962, 1971] suggested that
DHEA was abnormally low in women who developed breast cancer,
even as much as nine years prior to the onset or diagnosis of
the disease. Of the 5000 women followed in the study, 27 developed
cancer. Most of the 27 had abnormally low levels of DHEA. Many
years later, Dr. Arthur Schwartz of Temple University found that
supplemental DHEA significantly protected cell cultures from the
toxicity of carcinogens. Cell cultures usually respond to powerful
carcinogens with mutations (changes in DNA), transformations (changes
in cell appearance), and a high rate of cell death. But when Schwartz
added DHEA along with the carcinogen, all three of these effects
were significantly diminished.
DHEA and Aging
The body's production of DHEA drops from about 30 mg at
age 20 to less than 6 mg per day at age 80. According to Dr. William
Regelson of the Medical College of Virginia, DHEA is "one
of the best biochemical bio-markers for chronologic age."
In some people, DHEA levels decline 95% during their lifetime
- the largest decline of an important biochemical yet documented.
DHEA levels are directly related to mortality (the probability
of dying) in humans. In a 12-year study of over 240 men aged 50
to 79 years, researchers found that DHEA levels were inversely
correlated with mortality, both from heart disease and from all
causes. This finding suggests that DHEA level measurements can
become a standard diagnostic predictor of disease, mortality and
lifespan. Furthermore, if animal results hold true, supplemental
DHEA may prevent disease, reduce mortality, and extend lifespan
in humans.
DHEA and Glucose Metabolism
Investigators have shown that DHEA inhibits glucose-6-phosphate
dehydrogenase (G6PDH), an enzyme that breaks down glucose. There
are two glucose-metabolizing pathways in the body, the catabolic,
energy-yielding pathway and the anabolic, biosynthetic pathway.
G6PDH happens to be the first enzyme in the biosynthetic pathway,
the one which results in the synthesis of fatty acids and ribose
(the sugar used in making deoxyribonucleic acid, or DNA). In simple
language, G6PDH turns glucose into fat.
DHEA: The Buffering Steroid?
DHEA may be unique among hormones for it's lack of specificity
for hormone receptor sites. Just as vitamin E has never been shown
to have a specific metabolic role (it is only proven essential
as a general antioxidant), DHEA may serve an equally general purpose.
DHEA is the first example of a buffer action for hormones
that I know of," states William Regelson. "It is a
broad-acting hormone that only demonstrates itself under a specific
set of circumstances. In that way, it is like a buffer against
sudden changes in acidity or alkalinity. That is why when you
get older, you're much more vulnerable to the effects of
stress. As DHEA declines with age, you are losing the buffer against
the stress-related hormones. It is the buffer action that [helps
prevent] us from aging." The decrease of DHEA with age may
result in gradual decline of a system for suppressing enzyme systems
responsible for creating the building blocks of new cells, like
lipids, nucleic acids (RNA and DNA) and sex steroids. The resulting
rise in enzymatic activity in advanced age may be responsible
for the proliferative events (cancer) and degenerative disease
that become more frequent in advanced age. In this respect, DHEA
might be best considered to be an anti-hormone, which might "de-excite"
steroid-sensitive receptors that would otherwise lead to enhanced
metabolic activity.
|