Two very important life-style choices might be of significant benefit if you want to prevent a recurrence of colon cancer.
A recently released study identified both regular exercise (60 minutes weekly) and twice weekly fish meals as factors associated with a reduced risk of cancer recurrence.
The newly identified benefit of regular fish consumption, i.e., reduced colon cancer recurrence, aligns well with what else we know about the health benefits of eating fish. Eating omega-3 rich fish (salmon, cod, herring, and other cold water fish) has been previously identified with a reduced breast cancer risk. (As an aside, there are several ways in which colon cancer and breast cancer behave similarly, namely in the protective effects of vitamin D adequacy, benefits from exercise, and possible protection associated with bio-identical hormone replacement in menopause.)
Twice-weekly fish frequency has been shown to be associated with reduced cardiovascular risk, even in high risk patients, and healthy brain function: reduced rates of depression and other cognitive functions. I recommend to my patients that they enjoy wild-caught fish twice a week (relying primarily on red meat and poultry for other protein sources) and that at least one time the fish be from cold water for the extra boost of omega-3's.
Although some people worry about the mercury load identified in seafood, most fish contains adequate selenium, which binds with mercury in our digest tracts and prevents us from absorbing the mercury. We don't absorb the selenium either, so continued enjoyment of Brazil nuts and organ meats can help keep selenium levels normal.
Eating fish more than twice a week will not be harmful to your health in the short run, but in the long run it is very reasonable to be concerned about the continued availability of seafood. We have drastically reduced the numbers of wild fish, so you are doing your part to help protect the oceans if you choose good wild-caught fish and enjoy it twice a week!