|
|
Dehydroepiandrosterone
(DHEA) |
| |
|
Overview |
|
Dehydroepiandrosterone (DHEA) is the most abundant androgen (15 to 30 mg/day)
secreted by the adrenal glands and to some extent by the ovaries and testes. It
is a precursor for other steroid hormones, such as testosterone and estrogen.
Peak levels of DHEA occur at age 25. By age 80, DHEA levels have decreased to
10% to 20% of the peak level. DHEA has been called an antiaging hormone because
deficiencies of DHEA in old age may make individuals more susceptible to cancer
of the breast, prostate, bladder; atherosclerosis; hypertension; autoimmune
diseases (e.g., diabetes, lupus erythematosus, rheumatoid arthritis);
osteoporosis; high cholesterol; obesity; memory disturbances; chronic fatigue;
and manifestations of aging (older persons with these conditions have been found
to have low levels). When given to older patients, DHEA increased feelings of
physical and psychological well-being; increased immune cell production; and
enhanced mood, energy, and sleep. Older individuals with higher DHEA levels are
often in better health than individuals with lower levels. The two most
important factors concerning DHEA are its decline in old age and its deficiency
in several major disease states. |

|
|
Dietary Sources |
|
Most of the DHEA on the market is made in laboratories from sterols
(especially diosgenin) extracted from wild yams found in Mexico. Some extracts
from wild yams are marketed as "natural DHEA." These extracts of diosgenin are
supposedly converted into DHEA by the body. However, because it takes several
chemical reactions to convert diosgenin into DHEA, it is unlikely that the body
can make this conversion. Thus, only pharmaceutical grade DHEA should be
used. |

|
|
Constituents/Composition |
|
DHEA is a weak androgen synthesized in large quantities by the adrenal
cortex. However, it can be converted into more potent androgens (testosterone
and estrogen) throughout the body as needed. Only a small percentage of the
body's DHEA (5%) is in the active form; the rest (95%) is attached to sulfur
molecules (DHEA-S)—that is, it is sulfated by the
liver—and serves as a reserve to be converted to the
active form when needed. When blood levels of DHEA are measured, DHEA-S is
usually the measurement taken. |

|
|
Commercial
Preparations |
|
DHEA is available in capsules, chewing gum, or drops that are placed under
the tongue. DHEA is either natural or synthetic. However, it is debatable
whether the body can process diosgenin into steroid hormones. Thus, it is
recommended that only "pharmaceutical grade" DHEA be taken. |

|
|
Therapeutic Uses |
|
- Heart disease. Men with heart disease have low levels of DHEA-S. In
one study, healthy men with low levels of DHEA-S were three times more likely to
eventually die of heart disease than those with high levels of
DHEA-S.
- Obesity. Experimental animals given DHEA did not become obese, but a
control group given no supplements did become obese when given the same amount
of food. In human studies, DHEA has not demonstrated a beneficial effect on body
composition, even at high doses.
- Aging. Significant positive changes (e.g., less muscle wasting, less
memory loss, improved mood and energy) have been seen in elderly men given
DHEA.
- Osteoporosis. DHEA given to postmenopausal women increases bone mass.
However, supplementation is not recommended until more extensive human trials
have been conducted.
- Cancer. Experimental animals bred for breast cancer did not develop
cancer when given DHEA supplements. Also, women with breast cancer have low
levels of DHEA.
- Autoimmune disease. Low levels of DHEA have been found in patients
with autoimmune disorders (e.g., lupus erythematosus, rheumatoid arthritis,
multiple sclerosis, ulcerative colitis, AIDS). DHEA supplements improved stamina
and overall sense of well-being in patients with autoimmune disorders. Patients
with lupus treated with DHEA have shown symptomatic improvement, especially of
kidney function, often permitting a reduction of their
corticosteroids.
- Depression. DHEA has been used experimentally, to treat depressed
patients. Improvements in both depression and memory were observed.
- AIDS. DHEA treatment in AIDS patients may have promise since low DHEA
levels have been correlated with decreased immune function. However, controlled
trials have not been conducted to investigate this supposition.
- Performance enhancement. Because DHEA is thought to build muscle
mass, reduce fat, and reduce recovery time following injury, it is popular with
athletes. However, human studies are needed to verify these claims. DHEA is also
used to enhance sexual performance.
|

|
|
Dosage Ranges and Duration of
Administration |
|
DHEA is available without a prescription. Dosages for men and women differ;
men seem to tolerate higher doses. Men can safely take up to 50 mg/day; women
should not take more than 25 mg/day. Positive effects have been noted at dosages
as low as 5 mg/day. Because the long-term effects of DHEA supplementation have
not been studied and data from clinical trials is virtually nonexistent, the
safety and efficacy of DHEA has not been determined. |

|
|
Side
Effects/Toxicology |
|
High doses of DHEA are associated with negative side effects for both men and
women. However, the administration of high doses may be appropriate when
treating serious illness (e.g., autoimmune diseases). High doses may inhibit the
body's natural ability to synthesize DHEA and may be hepatotoxic. In addition,
women should be alert for any signs of masculinization because the end products
of DHEA in women are androgens (male hormones). Possible signs include loss of
hair on the head, hair growth on the face, weight gain around the waist, and
acne. Men should also be alert for signs of excess testosterone (e.g., sexual
aggressiveness, testicular atrophy, aggressive tendencies, male pattern
baldness, and high blood pressure). Blood levels of DHEA should be checked every
six months. |

|
|
Warnings/Contraindications/Precautions |
|
Because DHEA is a precursor of estrogen and testosterone, patients with
hormone-sensitive cancers (e.g., breast, prostate, ovarian, testicular) should
avoid taking DHEA.
DHEA is not recommended for people under the age of 40, unless DHEA levels
are known to be low (<130 mg/dL in women and <180 mg/dL in men).
The International Olympic Committee and the National Football League recently
banned the use of DHEA by athletes because its effects are very similar to
anabolic steroids. |

|
|
Interactions |
|
Azidothymidine
(AZT);
Zidovudine
When AZT-resistant and AZT-sensitive human HIV-1 cell isolates were
inoculated with DHEA (50 µM), viral replication was suppressed by over 50% (Yang
et al. 1994). The addition of DHEA enhanced the cytopathic effect of AZT and
inhibited reverse transcriptase activity. DHEA may play a role in the treatment
of HIV infection as an adjunct to conventional therapies by inhibiting
replication of HIV-1 cells and preventing resistance to
AZT. Barbiturates
DHEA (20 mg/kg) caused a dose-dependent increase in sleep time and enhanced
the hypnotic and hypothermic effects of pentobarbital in male mice (Melchior and
Ritzmann 1992).
Cisplatin
Pretreatment with DHEA-supplemented diets (6% w/w) amplified therapeutic
effects derived from a chemotherapeutic regimen of cisplatin (6 mg/kg) and AZT
(400 mg/kg) for the treatment of colorectal carcinoma in mice (Klann et al.
1992). These results warrant further study to determine whether DHEA
supplementation enhances the effectiveness of chemotherapeutic regimens in
humans. Prednisolone
Although DHEA alone was 1000 times less potent than prednisolone alone,
synergy existed when DHEA was combined with prednisolone to inhibit rat
lymphocyte proliferation (Meno-Tetang et al. 1996). Combination therapy could
lower the doses of corticosteroids necessary to treat inflammatory
disorders. |

|
|
References |
|
Balch JF, Balch PA. Prescription for Nutritional Healing. 2nd ed.
Garden City Park, NY: Avery Publishing; 1997:544-555.
Klann RC, Holbrook CT, Nyce JW. Chemotherapy of murine colorectal carcinoma
with cisplatin and cisplatin plus 3'- deoxy-3'- azidothymidine. Anticancer
Res. 1992;12:781-788.
Melchior CL, Ritzmann RF. Dehydroepiandrosterone enhances the hypnotic and
hypothermic effects of ethanol and pentobarbital. Pharmacol Biochem
Behav. 1992;43:223-227.
Meno-Tetang GML, Hon YY, Jusko WJ. Synergistic interaction between
dehydroepiandrosterone and prednisolone in the inhibition of rat lymphocyte
proliferation. Immunopharmacol Immunotoxicol. 1996;18(3):443-456.
Mindell E, Hopkins V. Prescriptions Alternatives. New Canaan, Conn:
Keats Publishing; 1998:473-476.
Reynolds JE. Martindale: The Extra Pharmacopoeia. 31st ed. London:
Royal Pharmaceutical Society; 1996:1504.
Shealy CN. The Illustrated Encyclopedia of Healing Remedies.
Shaftesbury, England: Element Books; 1998:273.
Yang J, Schwartz A, Henderson EE. Inhibition of 3' axido-3'
deoxythymidine-resistant HIV-1 infection by dehydroepiandrosterone in vitro.
Biochem Biophys Res Commun.
1994;201(3):1424-1432. |

|
Copyright © 2000 Integrative Medicine
Communications This publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
from the application, use, or misuse of any of the information contained herein,
including any injury and/or damage to any person or property as a matter of
product liability, negligence, or otherwise. No warranty, expressed or implied,
is made in regard to the contents of this material. No claims or endorsements
are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
for changes and new information regarding dosage, precautions, warnings,
interactions, and contraindications before administering any drug, herb, or
supplement discussed herein. | |