Not All Carbs Created Equal
Despite all the questions about how much of our diet carbohydrates should make up, researchers say we may be overlooking a more important issue: the kinds of carbohydrates we eat. Studies now demonstrate quite clearly that carbohydrates like white bread and sweets can't provide the kind of the health benefits offered by whole-grain breads, fruit and vegetables.
Forty studies have linked regular consumption of whole grains with a 10 to 60 percent lower risk of certain cancers, especially cancers of the stomach and colon. Several large studies have found greater use of whole grains associated with lower risk of heart disease, too. In the Iowa Women's Health Study, those who ate the most whole grains suffered about 20 percent fewer heart disease deaths and 10 percent fewer cancer-related deaths than those who ate the least, even after controlling for the effects of weight, smoking and other dietary habits.
At first, the health benefits of whole grains were attributed to dietary fiber. But since the discovery of natural, health-promoting phytochemicals and the growing recognition of the importance of antioxidants, scientists now place more emphasis on whole grains as a package of vital substances. Studies have shown that some of the phytochemicals in whole grains can block DNA damage that could lead to cancer. They can even suppress growth of cancer cells.
The outer layer of whole grains contains lignans, a form of phytoestrogen that may help protect against hormonally related cancers. Whole grains also provide a variety of trace minerals and antioxidant nutrients like vitamin E and selenium but, when grains are refined, 70 percent to 80 percent of many of these valuable substances are lost.
Is it possible that the health benefits attributed to eating whole grains are really due to other habits? It's true that several studies noted that those who ate more whole grains also ate more fruits and vegetables, clearly a major step in lower heart disease and cancer risk. In fact, the American Institute for Cancer Research says that 20 percent of cancers could be prevented by eating the recommended amounts of fruits and vegetables. Several studies, however, including the Iowa Study noted above, showed that the benefits of eating more whole grains remained significant, even after allowing for other eating habits like eating more fresh vegetables and fruits, or avoiding excessive amounts of meat.
How much does it take? The group of people in the Iowa Women's Health Study who ate the most whole grains actually consumed just over the minimum recommended, which is three servings a day. Although that's significant compared to the group that ate only one or two servings a week, three a day is not a difficult target to reach.
At breakfast, choose a whole-grain cereal, toast, or bagel. Depending on your portion size, that could equal one or two servings. If you have a sandwich at lunch made with whole-wheat bread, you've already met the goal. For other sources of whole-grain nutrition, choose brown rice, corn or whole-wheat tortillas and whole-wheat pasta. If you use mixes to prepare muffins and quick breads, make them from scratch instead, substituting whole-wheat flour. That only takes a few extra minutes but results in lots of extra nutrition.
A diet centered on white bread, fat-free cookies, pretzels and bagels is not a basis for good health. We need to focus on a variety of whole grains, vegetables, fruits and beans for the many different health benefits they bring, as well as their great taste.