Unlike many other
cancers, colorectal cancer sends out advance warnings of its arrival. A
precancerous polyp detected in the colon during a preventive screening can help
motivate you to adopt a colon-healthy diet.
If you’ve had a polyp
or a diagnosis of colorectal cancer, you’ll want to know how to structure a diet to prevent a recurrence of your condition. “There
isn’t nearly as much research on survivorship and recurrence as there is on
prevention, but from what we’ve seen so far, our best advice is for our cancer
survivors to follow our prevention guidelines,” says Colleen Doyle, MS, RD,
director of nutrition and physical activity for the American Cancer Society.
Unless extraordinary
health conditions dictate some variance, the standard cancer prevention
guidelines hold sway for two reasons. First, the prevention guidelines are
based on extensive analysis of diet and cancer, and frequently describe the
best-known strategies for avoiding a recurrence.
Second, a generally
well-balanced cancer prevention diet can help prevent a return of the disease
not only in the colon, but also elsewhere in the body. “Survivors of a
particular type of cancer can still be at risk for other types of
cancers," Doyle says. Since a cancer survivor is at higher risk for many
different cancers, not just the cancer of the original site, it is important to
control one’s overall cancer risk as much as possible. “The overall risk of
most cancer is going to be reduced by following those nutrition and physical
activity guidelines,” Doyle says.
Colorectal Cancer and
Diet: What to Eat, What to Avoid
What you should eat
and what you should avoid are equally important.
What helps. The colorectal
cancer prevention diet is plant-based, and includes the standard recommendation
of five servings of richly colored — think of a rainbow — fruits and vegetables
every day. Alcohol should be limited to one drink per day for women, two for
men. Fats should be used in moderation, and consist mostly of
those found in fish and plant sources.
What doesn’t help. A limited amount
of research has identified several dietary strategies that seem to have no benefit
in preventing the recurrence of precancerous polyps. Within three to four years
from the original polyp, no protective effect in preventing new polyps was
found from antioxidant vitamins,fiber supplements, or modest dietary changes to increase
fruit and vegetable intake.
What might help. There is some
evidence that calcium supplements provide some benefit in preventing polyp
recurrence. But because high levels of calcium are implicated in prostate cancer,
Doyle recommends that men make sure they get the recommended dosage of calcium
— preferably through plant sources — and no more.
After a diagnosis of colorectal cancer, the most important determinants of survival
seem to be adherence to the full treatment regimen (especially if chemotherapy
is recommended) and regular colonoscopies to identify new lesions. Colorectal
cancer treatment may require specialized nutritional counseling to develop a
tailor-made food plan, particularly if surgery has removed part of the colon
and affected how the body absorbs nutrients, Doyle says