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Life Extension Magazine

LE Magazine May 2004
Vitamins C and E Found to Prevent Alzheimer’s Disease

Taking vitamin C and E supplements together significantly lowers the risk of developing Alzheimer’s disease, according to a new study published in the Archives of Neurology.*

The research began in 1995, when approximately 5,000 elderly residents of Cache County, Utah, were assessed for dementia and Alzheimer’s disease. They were also questioned about their use of vitamin supplements. The researchers again assessed the participants’ mental status an average of three years later.

At the beginning of the study, those participants who had already been taking vitamin C and E supplements in combination had a 78% lower risk of having Alzheimer’s disease than those who were not taking the supplements. This benefit seemed to persist, as the risk factor for Alzheimer’s was 64% lower for supplement users at the end of the study period.

“The results of our study suggest that taking vitamins E and C in supplement doses (greater than 400 IU of E and 500 mg of C) may reduce the risk of developing Alzheimer’s disease,” lead researcher Dr. Peter Zandi of the Johns Hopkins Bloomberg School of Public Health told Life Extension.

The researchers believe that the vitamins’ antioxidant properties account for their protective powers against the oxidative stress-related damage that leads to Alzheimer’s disease. Interestingly, no evidence of a protective effect was seen with the use of vitamin C or vitamin E supplements alone, with multivitamins alone, or with vitamin B-complex supplements. The researchers suspect that the use of vitamins C and E probably offers protection against Alzheimer’s disease only when taken together in the higher doses available in individual supplements.

—Marc Ellman, MD

Reference

* Zandi PP, Anthony JC, Khachaturian AS, et al. Reduced risk of Alzheimer’s disease in users of antioxidant vitamin supple- ments: the Cache County Study. Arch Neurol. 2004 Jan;61(1):82-8.

Vitamins C and E Boost Cognitive Function in Elderly Women

Long-term use of vitamin C and E supplements appears to improve cognitive function in older women, research suggests.*

In an effort to determine the effect of supplement use on mental agility, researchers at Brigham and Women’s Hospital in Boston conducted telephone interviews of nearly 15,000 female participants in the Nurses’ Health Study. At the time of the interviews, all of the women were between 70 and 79 years of age. The researchers tested cognitive function by asking the women to perform such tasks as recalling a list of 10 words and repeating a series of numbers backwards. They then compared the results to the women’s self-reported use of vitamin supplements.

“We found evidence of better overall performance on our cognitive tests among long-term users of vitamins E and C combined than among women who had never taken either vitamin, and performance improved significantly with increasing duration of use,” wrote the researchers in the American Journal of Clinical Nutrition.

The two antioxidants appear to work best together, as vitamin C supplementation alone had no effect on cognitive function and vitamin E supplementation alone had minimal effect when compared to taking the two antioxidants together.

—Marc Ellman, MD

Reference

* Grodstein F, Chen J, Willett WC. High-dose antioxidant supplements and cognitive func- tion in community-dwelling elderly women. Am J Clin Nutr. 2003 Apr;77(4):975-84.

Fiber Slows Progression of Atherosclerosis

Consumption of dietary viscous fiber appears to decrease the progression of atherosclerosis, according to researchers at the University of Southern California in Los Angeles.*

Atherosclerosis describes the deposition of fat-laden plaques on the inside walls of the body’s medium- and large-sized arteries, which is associated with the development of cardiovascular disease. To determine the effect of fiber consumption on the development of atherosclerosis, the researchers measured the thickness of the carotid arteries (major blood vessels in the neck) of more than 500 adults. They then repeated these measurements twice over the next three years, and compared their findings to the participants’ reported fiber consumption and blood cholesterol levels.

The researchers found that the participants with the highest fiber consumption had the most optimal cholesterol levels. They also found that the more viscous fiber that the participants consumed, the slower their progression of carotid artery wall thickening. Viscous fibers, which were previously termed “water-soluble fibers,” include pectin, gums, and mucilage. Many fruits and vegetables are rich in viscous fibers.

“Cardiovascular disease due to advanced atherosclerosis is the leading cause of death and disability in the United States,” noted the researchers in the American Journal of Clinical Nutrition. “The present study suggests that increased dietary fiber intake has significant cardiovascular benefit and that the regulation of serum lipids by dietary fiber may be partially involved in the process of slowing the progression of atherosclerosis.”

—Marc Ellman, MD

Reference

* Wu H, Dwyer KM, Fan Z, Shircore A, Fan J, Dwyer JH. Dietary fiber and progression of atherosclerosis: the Los Angeles Atherosclerosis Study. Am J Clin Nutr. 2003 Dec;78(6):1085-91.

Curcumin Shown to Inhibit Tumor Angiogenesis

APN, a membrane-bound enzyme (CD13/aminopeptidase N), is found in tumor and other types of blood vessels undergoing the formation and differentiation of blood vessels (angiogenesis). However, it is not found in the vessels of other normal tissues. Because of this, APN is considered critical in anticancer therapies that seek to block tumor angiogenesis and metastasis. Curcumin, a potent chemopreventive agent, is now in clinical trials because it binds to APN and blocks its activity, thereby inhibiting tumor cell invasion and angiogenesis.

In recent studies, curcumin inhibited the invasiveness of human cancer cells (melanoma and fibrosacoma) that contained APN, indicating that APN is the direct target for curcumin anti-invasive activity. Curcumin also inhibited growth-factor-induced angiogenesis in endothelial cells.

The study authors conclude that targeted APN inhibition is a novel approach to prevent tumor angiogenesis and metastasis, and that the possible development of potent derivatives of curcumin may be considered, since APN has been defined as the functional target of the compound for antiangiogenesis.

—Carmia Borek, PhD

Reference

* Shim JS, Kim JH, Cho HY, et al. Irreversible inhibition of CD13/aminopeptidase N by the antiangiogenic agent curcumin. Chem Biol. 2003 Aug;10(8):695-704.

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