Eat to Live 47The studies mentioned above did not show that a diet high in fresh
fruits, vegetables, beans, whole grains, and raw nuts and seeds does
not protect against colon cancer. It has already been adequately dem-
onstrated in hundreds of observational studies that such a diet does of-
fer such protection from cancer at multiple sites, including the colon.
The first study merely added a fiber supplement to the diet. I
wouldn't expect adding a 1 3.5-gram fiber supplement to the disease-
causing American diet to do anything. It is surprising that this study
was actually conducted. Obviously, adding supplemental fiber does
not capture the essence of a diet rich in these protective plant foods.
The second study compared controls against a group of people
who were counseled on improving their diet. The participants con-
tinued to follow their usual (disease-causing) diet and made only a
moderate dietary change — a slight reduction in fat intake, with a
modest increase in fruits and vegetables for four years. The number
of colorectal adenomas four years later was similar. Colorectal ade-
nomas are not colon cancer; they are benign polyps. Only a very
small percentage of these polyps ever advance to become colon can-
cer, and the clinical significance of small benign adenomas is not
clear. In any case, it is a huge leap to claim that a diet high in fruits
and vegetables does not protect against cancer. This study did not
even attempt to address colon cancer, just benign polyps that rarely
progress to cancer.
In both studies, even the groups supposedly consuming a high-
fiber intake were on a low-fiber diet by my standards. The group
consuming the most fiber only ate 25 grams of fiber a day. The high-
fiber intake is merely a marker of many anti-cancer properties of
natural foods, especially phytochemicals. The diet plan I recommend
is not based on any one study, but on more than two thousand stud-
ies and the results I've seen with thousands of my own patients. Fol-
lowing this plan, you will consume between 50 and 100 grams of
fiber (from real food, not supplements) per day.
In an editorial, published in the same issue of the New England
Journal of Medicine, Tim Byers, M.D., M.P.H., basically agreed, stating,
"Observational studies around the world continue to find that the
risk of colorectal cancer is lower among populations with high in-
takes of fruits and vegetables and that the risk changes on adoption
of a different diet."^57 He further explained that the three- or four-
year period assessed by these trials is too brief and cannot assess the
effects of long-term dietary patterns that have already been shown to
protect against colorectal cancer.