Numbers Game: Answer

It is estimated that 30 to 40 percent of all cancers are directly linked to diet and exercise (mainly as a result of not eating enough health-promoting foods and not performing sufficient amounts of physical activity).

Source: American Institute for Cancer Research

Similarly, the National Cancer Institute estimates that up to 35 percent of cancer deaths are diet related.

Believe it or not, the notion that diet had anything to do with risk reduction of certain cancers was considered laughably by the medical community as little as thirty years ago.

By far the most important institution that has consistently -- and successfully -- worked on showing the strong links between diet and cancer risk within the scope of science-based clinical research is the highly respected American Institute for Cancer Research, which turns 27 years old this year.

Among their recommendations -- which include limiting consumption of salty foods and basing one's diet on fruits, vegetables, whole grains, and legumes -- the AICR strong suggests a weekly intake of no more than 18 ounces of red and processed meats, as the evidence between their consumption and a higher risk of colorectal cancer is too strong to ignore.