Dear John,
Supporters of low-carbohydrate diets say that carbs raise blood sugar and insulin levels, causing our bodies to store more fat. They say we should stay away from grains and starches, and instead eat animal protein and fat, which they say keep blood sugar levels low. I have read your section on these diets in The Food Revolution carefully. You say that diets high in animal fat and protein have harmful effects on our health, which I admit seems to be pretty well proven. You also say that the problem is that we eat too many processed and refined grains, and not enough whole grains. What scientific evidence can you present for this? Is there any solid proof that whole grains are healthy?
A stickler for the truth
Dear stickler,
Both whole and refined grains are high in carbohydrates, but they do not act the same way in the body. Whole grains include all parts of the plant kernel, including the fiber-rich bran and the nutrient-rich germ. Refined grains, on the other hand, have had these nutritious components stripped away during milling. Whole grains provide important nutrients including B vitamins and vitamin E, and many other health-promoting substances. The rapid fluctuations in blood sugar levels and the other problems the anti-carb crusaders are seeking to correct are primarily caused by refined grains and sugars. The fiber found in whole grains slows these fluctuations, helps lower cholesterol levels, keeps the digestive tract healthy, and provides many other advantages.
You ask for scientific evidence. In 2001, a study was published in the Journal of the American Dietetic Association titled “The role of whole grains in disease prevention.” The authors conducted a meta-analysis on the subject by reviewing the available scientific literature on whole grains and cancer risk. The findings were as follows:
Out of 45 studies on whole grains and cancer, 43 showed whole grain intake to provide significant protection from several cancers. Specifically, a protective association was seen in 9 out of 10 mentions of studies on colorectal cancers and polyps, 7 out of 7 mentions of gastric cancer, 6 out of 6 mentions of other digestive tract cancers, 7 out of 7 mentions of hormone-related cancers (breast cancer, prostate cancer, ovarian cancer and uterine cancer,) 4 out of 4 mentions of pancreatic cancer, and 10 out of 11 mentions of other cancers.
Meanwhile, 98% of the wheat eaten in the United States is eaten as white flour.
To your health,
John
