1999-05-01
Ray Sahelian

A new, promising botanical therapy for Alzheimer's disease.

A new botanical extract has become available over the past year that promises to offer a natural alternative to drugs used for Alzheimer's disease. This supplement, called huperzine A, is an extract from the club moss Huperzia serrata, and has been used for centuries in Chinese folk medicine.

Alzheimer's Disease (AD), a progressive deterioration in mental functioning, first described by Alois Alzheimer in 1907, affects more than 4 million Americans. The onset most commonly starts in one's 80s, although it has been known to start as early as age 30. One of the major cognitive problems associated with AD is the inability to acquire new knowledge. Loss of the sense of smell is common, and the mental deterioration proceeds to affect language and motor skills.

In Alzheimer's disease, there is a shortage of acetylcholine, the brain chemical involved in memory and learning. For many years, doctors have prescribed a drug called tacrine that elevates levels of acetylcholine by blocking the activity of acetylcholinesterase, the enzyme that breaks it down.

The action of huperzine A is similar to tacrine. It also has the ability to inhibit the activity of acetylcholinesterase. By inhibiting this enzyme, more acetylcholine becomes available to stimulate neurons. Several studies have been done over the past few years with huperzine A, both in China and the United States.

These studies have shown that huperzine A:

* Is many times more effective and selective than tacrine (a pharmaceutical drug) in inhibiting acetylcholinesterase.

* Is beneficial in patients with Alzheimer's disease. Scientists at Zhejiang Medical University, in Hangzhou, China, administered, for a period of eight weeks, 0.2 mg of huperzine A to 50 participants with Alzheimer's disease, and compared the results to a group which received placebo pills. The study was done in a double-blind, placebo-controlled, and randomized manner. The results showed about 58 percent (29 out of 50) of the patients treated with huperzine A had improvements in memory, cognition, and behavioral functions, whereas only 36 percent of those on the placebo improved. No severe side effects were found. The researchers say, "Huperzine A is a promising drug for the symptomatic treatment of Alzheimer's disease."

Huperzine A was discussed, in 1997, in the Journal of the American Medical Association as a possible botanical treatment option for Alzheimer's disease.

* Benefits older people with dementia, as seen in a double-blind study on 56 patients with multi-infarct dementia (multiple small strokes) and 100 patients with senile memory disorders (Zhang, 1991). The intra-muscular dose used for multi-infarct dementia was 0.05 mg twice a day for four weeks, whereas that for senile memory disorders was 0.03 mg twice a day for two weeks. Only a few patients felt slight dizziness, but this did not affect the therapeutic effects.

Availability. Huperzine A is sold either by itself in dosages of 0.05 mg or in lower dosages combined with other nutrients that enhance memory and mental function. Daily dosage is about 0.05 to 0.1 mg a day, taken in the morning.

Recommendations. Huperzine A appears to be a promising alternative to acetylcholinesterase-inhibitor drugs used in Alzheimer's disease. Patients who take huperzine A have reported feeling slightly more alert and focused. Until we learn more about this botanical extract, I recommend its use in the therapy of Alzheimer's disease, and only under the supervision of a healthcare practitioner.

Editor's Note: The safety and efficacy profile of huperzine A, to date, suggests cognition and memory benefits applicable to the general population.

REFERENCES

Cheng, D.H., Ren, H., and X.C. Tang. "Huperzine A, a novel promising acetylcholinesterase inhibitor," Neuroreport. 20;8(1):97-101, 1998.

Skolnick, A.A. "Old Chinese herbal medicine used for fever yields possible new Alzheimer disease therapy [news]," JAMA 12;277(10):776, 1997.

Xu, S.S., et al. "Efficacy of oral huperzine-A on memory, cognition, and behavior in Alzheimer's disease," Chung Kuo Yao Li Hsueh Pao 16(5):391-5, 1995.

Zhang, R.W., et al. "Drug evaluation of huperzine A in the treatment of senile memory disorders," Chung Kuo Yao Li Hsueh Pao. 12(3):250-2, 1991.

Ray Sahelian, M.D., is the bestselling author of books on Kava, Creatine, 5-HTP, Melatonin, DHEA, Glucosamine, Pregnenolone, Saw Palmetto, and CoQ10. New books include The Common Cold Cure and The Stevia Cookbook. See his web site www.raysahelian.com for the latest updates on natural therapies, herbs, hormones, and supplements.