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.
