Narrator: This is Science Today. DHEA, a hormone often touted to prevent cancer and slow down the aging process, may also protect the heart from a variety of cardiovascular diseases. Christian Zellner, a researcher at the University of California, San Francisco says it's important not to confuse the DHEA used in their study, with the DHEA sold at the health food store.

Zellner: We used the substance that is synthesized in adrenal gland called DHEA-sulfate. So the substance that we injected intravenously is not what you can buy over the counter. That's a big difference and you have to keep that in mind.

Narrator: In coronary arteries, DHEA-sulfate reversed the effects of a peptide called Endothelin-1, which is present in hypertension, heart attacks and angina.

Zellner: It acts as a direct vasodilator, possibly similar to nitroglyercin. We showed that it protects the endothelial cell and enhances the function of those inner-linings of the arteries and thirdly, it reduces the constriction of arteries to substances that might be elevated in heart diseases.

Narrator: For Science Today, I'm Larissa Branin.