July 23, 2003 — New research provides fresh insight into how the hormone DHEA might help prevent heart disease, but experts say it’s still much too early to start recommending DHEA supplements for heart health.
The study found that taking small doses of DHEA improved insulin sensitivity and endothelial function — two factors that contribute to the development of heart disease — in 24 middle-aged men with high cholesterol.
“The combined effect of these beneficial changes would be expected to minimize the progression of age-related disorders such as cardiovascular disease,” write researcher Hiroaki Kawano of Kumamoto University School of Medicine in Japan, and colleagues in the Journal of Clinical Endocrinology & Metabolism.
Beneficial but Controversial
Researchers say the benefits and risks of DHEA supplements remain controversial, but the results reveal how DHEA may work within the body to stall heart disease.
DHEA (dehydroepiandrosterone) is a steroidal hormone produced by the adrenal gland. Production peaks in the mid-20s and then declines with age. Because DHEA levels drop as a person’s risk of age-related health problems like heart disease increases, research on DHEA supplementation has focused on its potential anti-aging effects.
But experts say too little is known about the long-term effects of DHEA supplementation and warn this study should not be viewed as an opportunity to jump on the DHEA bandwagon.
“I think we still have to be very cautious with it,” says Frank Bellino, PhD, endocrinology program administrator at the National Institute on Aging at the National Institutes of Health. “This is just another piece of information that shows a positive effect, and we need to see more before we can make a recommendation.”
Researchers analyzed the effects of low-dose DHEA supplementation on two factors that are considered precursors to heart disease, insulin sensitivity and endothelial function, rather then its impact on heart disease outcomes, such as heart attack or stroke.
Two Improved Risk Factors
Insulin sensitivity — decreased ability of the body to handle sugars normally — decreases with age, and previous studies have shown that problems with reduced insulin sensitivity is closely linked to age-related diseases, such as heart disease. .
Endothelial cells form the lining of blood vessels in the heart and elsewhere in the body and help regulate blood flow. These cells produce substances that prevent blood clotting and vessel clogging by plaque. Endothelial dysfunction is known to contribute to atherosclerosis or hardening of the arteries.
The study found that men who received 25 mg per day of DHEA supplements for 12 weeks experienced significant improvement in endothelial function as well as insulin sensitivity compared with those who took a placebo.
Researchers say those benefits were achieved without increasing the level of testosterone circulating in the blood. Within the body, DHEA naturally is converted into either testosterone or estrogen, and previous studies have found DHEA supplementation can produce dangerous increases of these hormone levels, which can raise the risk of certain types of cancer and other diseases.