пятница, 14 сентября 2012 г.

Daily intake of whole-grain foods provides health benefits. - Emerging Food R&D Report

Several studies have shown that individuals who consume high quantities of whole-grain cereals have less of a chance of experiencing coronary heart disease. Breakfast cereals are a common component of the diet of children as well as adults. However, for adults, the mean intake of whole grains is only 1.2 servings per day. Based on observational studies, those eating three or more servings of whole-grain foods are at reduced risk of developing CVD and type-2 diabetes. Most health professionals recommend substituting whole grains for refined grains and recommend consuming at least three servings of whole grains.

Whole grains contain numerous compounds that possess antioxidant activity, which are not present in highly refined grains. Whole-grain oat- and wheat-based cereals and other products on average have higher antioxidant contents than corn- or rice-based food products.

Breads labeled 'whole wheat' must by law meet a standard, which is that they be made only from whole-wheat flour. Such breads rank comparatively high in fiber content because their wheat bran and wheat germ have not been removed. Wheat germ is the small, inner part of the wheat kernel that is a concentrated source of nutrients.

The distinction is important. A recent study funded by USDA-ARS showed that those who consumed at least three servings of whole-grain foods per day were less likely to have what's called metabolic syndrome. That's a condition marked by a combination of abdominal obesity, high triglycerides, low HDL cholesterol, high blood pressure and poor blood sugar control--all of which increase risk for diabetes and heart disease.

When wheat is ground into flour, the bran and germ can be removed, and that decreases the amount of fiber in wheat products. Some breads labeled simply 12-, 9- or 7-grain, for example, could have just one-third of the fiber of similarly labeled whole-wheat breads. The term 'enriched wheat flour' means that certain nutrients were added back into the flour during or after processing, but that doesn't mean that fiber was added back in. Such a bread is not whole-grain. Foods that have at least 2.5 grams of fiber per serving are considered to be good sources of fiber and can make this claim on the wrapper, say FDA regulations.

Further information. Nicola McKeown, Nutritional Epidemiology Program, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington St., Boston, MA 02111; phone 617-556-3367; fax: 617-556-3344; email: nicola.mckeown@tufts.edu.