Sticking to diet advice cuts colon cancer risk

Current dietary guidelines are on the right track when it comes to colorectal cancer prevention, new research from the National Cancer Institute (NCI) confirms.

Men whose eating habits adhered most closely to any of four indexes widely used to measure diet quality were less likely to develop colorectal cancer, Dr. Jill Reedy of the NCI's Division of Cancer Control and Population Sciences in Bethesda, Maryland, and colleagues found.

"Although these indexes may differ in philosophy and design, they really share a common theme," Reedy noted in an interview with Reuters Health. All recommend eating a diet rich in fruits, vegetables, whole grains and healthy oils; getting enough calcium and vitamin D through sources such as dairy products; and limiting consumption of solid fats, added sugar and red meat, she explained.

"Assessing overall dietary patterns is an important alternative to traditional methods in nutritional epidemiology that have focused only on single nutrients," Reedy and her team point out in the American Journal of Epidemiology.

She and her colleagues looked at the relationship between diet pattern and colorectal cancer risk in 492,382 men and women participating in the National Institutes of Health-AARP Diet and Health Study. They compared participants' eating habits to Healthy Eating Index-2005, the Alternate Healthy Eating Index, the Mediterranean Diet Score, and the Recommended Food Score.

Over five years of follow-up, 3,110 of the study participants developed colorectal cancer. Closely following any one of the four diet indexes reduced risk of the disease by 25 percent to 30 percent for men. However, the only diet pattern associated with reduced colorectal cancer risk for women was the Healthy Eating Index-2005.

The gender difference may have been related to differences in how women report their food intake, or it could also be because the Healthy Eating Index-2005 is more complex and able to provide a better sense of risks associated with eating extra sugar or solid fat, Reedy said.

Nevertheless, she added, the findings make it clear that following current recommendations for healthy eating may help prevent people from developing colorectal cancer.

While questions remain about how these eating patterns may promote health, Reedy said, the findings confirm that "we can still go ahead and think about changing our eating behaviors and changing our food environment" to make fruits, vegetables, whole grains and other healthy foods more widely available.

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SOURCE: American Journal of Epidemiology, July 1, 2008.