Ingredient Spotlight: Huperzine A

Since its introduction to U.S. markets in 1998, Huperzine A (HupA) has been aggressively marketed as a natural memory enhancer and concentration aid and is commonly paired with other memory-enhancing ingredients such as ginkgo, ginseng and vitamin E. Whether it is an effective preventive treatment for relatively healthy baby boomers, however, remains to be seen.

Several studies, including a 1997 review paper published in JAMA, indicate that HupA, a purified alkaloid compound isolated from Chinese club moss (Huperzia serrata), inhibits the breakdown of the neurotransmitter acetylcholine. Studies show that acetylcholine is rapidly broken down in the brains of Alzheimer's patients and a shortage of the neurotransmitter appears to contribute to their memory loss.

Like the two FDA-approved Alzheimer's drugs, tacrine hydrochloride and donepezil, that it is often compared with, HupA works by disrupting the enzyme that breaks down acetylcholine, yet it appears to do so more effectively and with fewer side effects. Now that researchers understand HupA's structure and how it works, they are designing more potent synthetic versions that will likely be developed into drugs.

Although sold as a dietary supplement, HupA is a highly purified and powerful compound referred to as a drug in nearly all clinical trials. To date, it has demonstrated effects only in people with age-related memory disorders and Alzheimer's disease.