|Life Extension Weekly Update Exclusive |
Fruit and grain fiber lower heart disease risk
Fiber from cereals and fruits, but not vegetables, was found to lower the risk of coronary heart disease (CHD) in a study published in the February 23 2004 issue of American Medical Association Journal, Archives of Internal Medicine. Few studies have broken down fiber according to type in regard to its protective benefit against heart disease.
The current study analyzed ten prospective studies that included 91,058 men and 245,186 women. Dietary intake of fiber was ascertained at the beginning of each study by the use of questionnaires completed by participants. Fiber intake from grains, fruits and vegetables was measured, as well as insoluble and soluble fiber. During six to ten years of follow-up, 5,249 cases or coronary heart disease were diagnosed and 2,011 deaths from the disease occurred.
Adjusted analysis found that each ten gram per day increment of fiber was related to a 14 percent decreased risk of coronary events and a 27 percent reduction in the risk of dying from heart disease. When analyzed separately, cereal fiber intake was associated with a 10 percent reduction in coronary events and a 25 percent reduction in coronary deaths, while fruit fiber intake was associated with an even lower risk of events and death, with a 16 percent and 30 percent reduction. Fiber from vegetables did not appear to be associated with either coronary events or deaths.
Mark Pereira, PhD, of the University of Minnesota, Minneapolis, and colleages conclude, "Our results suggest that dietary fiber intake during adulthood is inversely associated with CHD risk. Coronary risk was 10 percent to 30 percent lower for each 10 gram per day increment of total, cereal, or fruit fiber. Therefore, the recommendations to consume a diet that includes an abundance of fiber-rich foods to prevent CHD are based on a wealth of consistent scientific evidence. “
The intake of dietary fiber among people living in Western countries is low (about 17 grams a day in the United States), according to the Third National Health and Nutrition Examination Survey (NHANES). This is unfortunate, for soluble fiber offers significant protection against a number of risk factors associated with cardiovascular disease. For example, mucilages, guar gum, psyllium powder, oat bran, and pectin reduce cholesterol levels. Guar gum (5 grams with meals), psyllium powder (5 grams before meals), or pectin (10 grams with meals) reduce fasting and postprandial blood glucose, as well as insulin levels, in both healthy and diabetic subjects. If taken with meals, soluble fibers (6-10 grams a day) reduce iron absorption from foods, important to those with hemochromatosis or iron overload (Monnier et al. 1980).
Illustrative of the value of fiber, researchers from the Veterans Affairs Medical Center, the University of Kentucky (Lexington), and the Procter & Gamble Company (Cincinnati, OH) evaluated the effectiveness of psyllium as a hypocholesterolemic and blood glucose modulator. Thirty-four men with Type II diabetes and mild-to-moderate hypercholesterolemia were randomly assigned to receive 5.1 grams of psyllium or a cellulose placebo twice daily for 8 weeks. The psyllium group showed significant improvements in glucose and lipid values compared with the placebo group. Serum total and LDL-cholesterol concentrations were 8.9% and 13.0% lower, respectively, in the psyllium group compared to the placebo group. All-day and postlunch postprandial glucose concentrations were 11.0% and 19.2% lower in the psyllium group (Anderson et al. 1999). These impressive results occur as fiber binds bile acids, cholesterol, and fats, preventing their absorption. Short-chain fatty acids, products of fiber fermentation in the colon, further inhibit cholesterol synthesis by the liver.
Studies in the New England Journal of Medicine confirmed the value of a high fiber diet in improving glycemic control and reducing hyperinsulinemia and plasma lipid levels in patients with Type II diabetes (Chandalia et al. 2000). In a randomized, 6-week crossover study, 13 patients with Type II diabetes were given diets containing either moderate or high amounts of fiber. The moderate fiber allowance was 24 grams (8 grams of soluble and 16 grams of insoluble), an amount compliant with guidelines established by the ADA. The high-fiber diet consisted of 50 grams of fiber (25 grams soluble and 25 grams insoluble).
During the sixth week of the high-fiber diet (as compared with the sixth week of the ADA diet) the diet supplying 50 grams a day of fiber lowered plasma glucose 10%, insulin concentrations 12%, total cholesterol 6.7%, triglyceride levels 10.2%, VLDL 12.5%, and LDL cholesterol 6.3%. It is speculated that the decrease in triglycerides and VLDL may be due more to improved glycemic control than to a direct relationship with the fiber. There was no significant difference between the two diets in terms of HDL cholesterol levels. Note: The fiber-rich foods included in the study were cantaloupe, grapefruit, raisins, oranges, papayas, lima beans, okra, sweet potatoes, winter squash, zucchini, oat bran, and oatmeal.
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Bromelain is a mixture of sulfur-containing proteolytic enzymes obtained from the stem of the pineapple plant. Bromelain can help break down fibrous substances within the body so that they can be metabolized normally.
Curcumin can help maintain normal healthy platetlet function and the normal process of bile excretions.
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