Fighting Age-related MEMORY Decline

Prepared Foods, June, 2000 by Elizabeth Mannie

References

(1.) Margolis, S. and Rabins, P.V. Memory. The Johns Hopkins White Papers 2000. The Johns Hopkins Medical Institutions, Baltimore, Maryland.

(2.) Solfrizzi, V., et. al. 1999. High monounsaturated fatty acids intake protects against age-related cognitive decline. Neurology 52 (May 12): 1563- 1569.

(3.) Sano, M., et. al. 1997. A controlled trial of selegiline, alpha-tocopherol, or both as treatment for Alzheimer's disease. The Alzheimer's Disease Cooperative Study. N Engl J Med. Apr 24;336(17):1216-22.

On the Web: ALZHEIMER'S

* www.coa.uky.edu/nunnet/Overview of Nun Study

* www.centerwatch.com/studies/listing.htm List of clinical trials

* www.alz.org/hc/treatment/alternative.htm Alzheimer's Assoc. and alternative medicine

* www.alzheimers.org/National Institute of Aging (NIH)

Memory and Isoflavones

Several studies in the early 1990s on estrogen's ability to maintain memory in aging women yielded disparate results. More recent reports have tipped the balance in favor of estrogen. [1,2] For example, a 1998 study of 727 women noted that those who had used estrogen replacement therapy (HRT) scored significantly higher on cognitive tests than nonusers. [3] The effect was independent of age, education and ethnicity, and went beyond the risk of Alzheimer's Disease (AD). The report suggests that estrogen replacement therapy might help maintain cognitive function in "nondemented postmenopausal women.

What role could alternative HRTs such as isoflavones play?

"Because isoflavones are structurally like estrogen, they may mimic estrogen's actions," says Helen Kim, Research Associate Professor, Dept. of Pharmacology & Toxicology, University of Alabama at Birmingham. In menopause; estrogen-dependent systems become at risk for disease due to the reduction in estrogen.

AD is characterized by plaques of beta-amyloid protein fragments and tangles of a protein called tau. "Estrogen may protect against the accumulation of beta-amyloid fragments," says Kim.

Beta amyloid accumulation may play a role in causing tau tangles as well. Tau is associated with microtubules that transport messages along nerves. In part, due to beta amyloid aggregation, the tau proteins are chemically modified such that they leave the microtubules and form their own filaments. The microtubules then fall apart. Kim says the absence of these microtubules is as much a part of ADs pathology as the presence of plaques and tangles.

In research scheduled for publication, Kim found that the tau in animals that ate soy with isoflavones was less modified than in the animals that ate soy without isoflavones. So, while more research is needed, particularly with human subjects, the early data suggests that soy may have protective actions in the brain.

Claudia O'Donnell

References:

(1.) Tang, M.X., et. al., 1996. Lancet 1996. Aug. 17: 348 (9025): 420-1

(2.) Kawas, C. et al., 1997. Neurology, June; 48 (6): 1517-21

(3.) Jacobs, D.M, et. al., 1998. Neurology, Feb:50 (2):368-73

Info on the Web

The www.clinicaltrials.gov website is managed by the National Institutes of Health. More than 4,000 clinical studies are listed and include information such as location, design and purpose.