Reuters Health April 23, 2002 05:28 PM ET

Cut Bowel Cancer Risk by Eating Less, Better: Study

Reuters Health April 23, 2002 05:28 PM ET


By E. J. Mundell

NEW ORLEANS (Reuters Health) - Preliminary studies in mice suggest that smaller portions and healthier food choices may be key in keeping the gut and colon cancer-free.

Cancer-prone mice fed either a restricted-calorie diet or a diet rich in olive oil, fruits and vegetables were up to 60% less likely to develop pre-cancerous colon polyps compared with mice fed regular diets, according to investigators at the US National Cancer Institute, in Bethesda, Maryland.

The findings suggest that individuals who want to prevent intestinal and colon cancers "avoid overeating and consume a healthier diet rich in beneficial fatty acids (and) high in fruits and vegetables," according to lead researcher Dr. Volker Mai. He presented the findings here Tuesday at the annual Experimental Biology 2002 conference.

Numerous studies have supported the notion that the simple act of cutting back on daily calories can bring longer, healthier life. And nutritionists everywhere agree that diets heavy in fruits, vegetables and healthy oils work to fight a host of illnesses.

In their study, Mai's team had mice bred with a gene that left them highly susceptible to intestinal cancers placed on one of five diets. The mice were fed either a regular diet, a regular diet plus moderate exercise, a high-fat diet, a calorie-restricted (40% less) diet, or a diet high in olive oil, fruits and vegetables.

At the end of the study, the researchers examined the number of polyps--small pre-cancerous growths--in each mouse's gut.

Compared with mice on the regular diet, mice on the olive oil, fruit and vegetable regimen displayed 40% fewer polyps within the intestines and colon, while mice on the calorie-restricted meal showed a full 60% reduction in polyp development.

The combination of a regular diet plus exercise also reduced polyp development, but only slightly, the researchers add. On the other end of the scale, mice fed high-fat regimens displayed the most prolific polyp growth.

In an interview with Reuters Health, Mai said that "mice are obviously not men, but strong similarities exist between them." Although the mechanisms by which various foods affect health remain unclear, Mai speculated that low-calorie, plant-based diets may alter levels of hormones in the body that influence cancer development.

Still, firm conclusions as to the benefits of various diets to the human gastrointestinal tract can only come from clinical trials, he said. The next step, according to Mai, is to conduct more animal studies to determine if a combo regimen--calorie-restriction plus fruits and vegetables--can drive polyp counts down even further. The scientists also plan to research the potential of such diets in preventing other cancers, including breast cancer.

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