Natural Foods Merchandiser

Science Beat with Alan R. Gaby, M.D., and Kimberly Beauchamp, N.D., Healthnotes Inc.

Change cooking habits to fight aging and disease
A group of chemical compounds that form during cooking are believed to accelerate the aging process and to contribute to heart disease, Alzheimer?s disease and the organ damage caused by diabetes and kidney disease. Now, researchers at the Mount Sinai School of Medicine have measured the concentration of these toxic compounds in 250 commonly consumed foods and published their findings in the Journal of American Dietetic Association.

The chemicals in question, advanced glycation end products, are created when a sugar molecule hooks onto one of the amino acids of a protein or when a sugar combines with certain fats or other compounds in food. AGEs also form within the human body when glucose fuses to proteins, fats or DNA. There is strong evidence that AGEs produced within the body contribute to the aging process and to organ damage in people with diabetes.

Research performed over several years by the Mount Sinai group has shown that about 10 percent of the AGEs in food are absorbed into the body and remain in various tissues for considerable periods of time. Food-derived AGEs have some of the same adverse effects as the AGEs manufactured in the body. In animal studies, restriction of dietary AGEs slowed the progression of atherosclerosis and diabetes. A study in humans found that a low-AGE diet reduced blood levels of C-reactive protein, which is a measure of inflammation and a known risk factor for heart disease.

AGEs form as food browns during cooking, primarily when foods high in protein or fat are subjected to high temperatures. Cooking at a higher temperature for a shorter period of time creates more AGEs than cooking at lower temperatures for longer periods of time. Also, dry heat produces more AGEs than cooking in liquid. Thus, broiling, frying or grilling meats creates more AGEs than boiling, poaching or stewing. For example, a chicken breast broiled for 15 minutes contains more than five times as many AGEs as the same food boiled for one hour.

A typical American diet contains an average daily AGE intake of approximately 16,000 kilounits. This study makes it possible for people to reduce their daily intake of toxic AGEs. The researchers have shown previously that it is possible to vary the AGE content of the diet by as much as five-fold, by altering the cooking time and temperature. While additional research is needed, the evidence so far suggests a benefit in decreasing AGE intake.

Alan R. Gaby, M.D., is the is the chief medical editor for Healthnotes Inc. and co-author of The Natural Pharmacy, 2nd Edition (Healthnotes, Three Rivers Press, 1999). Copyright ? 2004 Healthnotes Inc.

Dieters Need Extra Calcium
Postmenopausal women on diets require more calcium, according to the American Journal of Clinical Nutrition.

During periods of weight loss, bone mass may be lost, leading to an increased risk of bone fracture. The current study examined the effect of a weight-loss diet on calcium absorption in 57 overweight postmenopausal women. The women were assigned to either a weight-loss or a weight-maintenance group for six weeks. The weight-loss group received nutrition education and behavior modification training from a registered dietitian, and they lost weight through a combination of calorie restriction and regular physical exercise. The weight-maintenance group did not receive weight-loss training.

All participants took a daily multivitamin containing 200 mg of calcium and were assigned to receive either 200 mg or 1,000 mg of supplemental calcium (as calcium citrate) per day for six weeks. Dietary sources were intended to provide an additional 800 mg of calcium per day, so that the two groups received a total of 1,200 and 2,000 mg, respectively, of calcium per day. Daily calcium absorption was estimated, and other markers of calcium metabolism and bone turnover were assessed at the beginning and end of the study period.

Women in the weight-loss groups absorbed less calcium than women in the weight-maintenance groups, especially when weight loss was rapid. Women in the weight-loss group who received a total of 1,200 mg of calcium per day absorbed almost 20 percent less calcium than the daily requirement. Women in the weight-loss group receiving a total of 2,000 mg of calcium per day absorbed sufficient amounts of calcium to prevent bone loss.

This study suggests that postmenopausal women who are dieting should take supplemental calcium above the current recommended daily value of 1,200 mg of calcium to prevent bone loss. To add more calcium to the diet, rich sources include kale, collards, broccoli, sardines, almonds, soybeans, calcium-fortified orange juice, and dairy products.

Kimberly Beauchamp, N.D., is a co-founder and practicing physician at South County Naturopaths Inc., in Wakefield, R.I.

Natural Foods Merchandiser volume XXV/number 11/p. 49

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