Encyclopedia of Health and Medicine

D–F
dehydroepiandrosterone (DHEA) A steroid HOR-
MONE that occurs naturally in the body. It serves as
a precursor primarily to estrogen in women and
TESTOSTERONE in men, though women also convert
small amounts to testosterone and men convert
small amounts to estrogen. Levels of endogenous
DHEA gradually diminish with aging. As a supplement,
DHEA provides a similar source to the body
for these hormones. DHEA is available without a
doctor’s prescription in the United States, marketed
as a dietary supplement sold mostly in
health food stores.
People take DHEA supplement for numerous
and diverse uses such as to increase libido, reduce
the effects of aging, boost immune function, prevent
OSTEOPOROSIS, relieve symptoms associated
with FIBROMYALGIA and SYSTEMIC LUPUS ERYTHEMATO-
SUS (SLE), and prevent degenerative diseases
related to aging such as CARDIOVASCULAR DISEASE
(CVD). There is scant clinical evidence to support
any of these uses, and doctors worry that increasing
the body’s levels of sex hormones may
increase the risk for hormone-driven BREAST CAN-
CER and PROSTATE CANCER. There is some evidence
that long-term DHEA use damages the LIVER.
Though DHEA is an over-the-counter dietary
supplement in the United States, doctors encourage
people to obtain blood tests to measure their
levels of estrogen or testosterone before taking
DHEA. The greatest risk for adverse health circumstances
occurs when products such as DHEA
increase estrogen or testosterone blood levels to
higher than normal. Researchers believe this make
increase the risk for some cancers, although again
clinical evidence is lacking. Health experts recommend
that people under age 50 do not take DHEA
unless a doctor prescribes it to treat conditions in
which endogenous DHEA levels are low.
66
DEHYDROEPIANDROSTERONE (DHEA)
Uses Risks/Side Effects Interactions
FIBROMYALGIA acne flareups none known
SYSTEMIC LUPUS mood swings
ERYTHEMATOSUS (SLE) LIVER damage
mental alertness in
aging
slow OSTEOPOROSIS
See also ADRENAL INSUFFICIENCY; ANABOLIC
STEROIDS AND STEROID PRECURSORS; HUMAN GROWTH
HORMONE (HGH) SUPPLEMENT; MELATONIN.
dong quai An ancient remedy for relieving menstrual
and menopausal discomforts. It contains
phytoestrogens, which are estrogen-like chemicals
that are much weaker than those the human body
produces though are nonetheless capable of binding
with estrogen receptors. Researchers do not
know the extent to which dong quai’s phytoestrogens
have any effect in the body, however,
because dong quai contains other active ingredients
and often appears in combination with other
herbs. Dong quai (Angelica sinensis) also contains
coumarins, chemicals that cause smooth MUSCLE
tissue to relax. This effect dilates blood vessels,
increasing blood flow. It also acts to relax the
UTERUS, which is also smooth muscle tissue. Many
health experts believe coumarins are responsible
for most of dong quai’s effects. Dong quai is sold
as an over-the-counter dietary supplement in the
United States.
Dong quai also contains psoralens, chemicals
that interact in the SKIN when exposed to sunlight.
Psoralens intensify the effects of ultraviolet light
with the result of unusually rapid and severe SUN-
BURN. Women should limit sun exposure when
taking dong quai. Dong quai also may interact