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WEDNESDAY, Aug. 5 (HealthDay News) -- Intermittent calorie restriction may reduce the risk of breast cancer because it reduces insulin-like growth factor-1, according to an animal study published in the August issue of Cancer Prevention Research.
Olga P. Rogozina, M.D., of the University of Minnesota in Austin, and colleagues randomly assigned 10-week-old MMTV-TGF-α female mice that overexpress the human TGF-α oncogene to receive either an ad libitum diet, an intermittent calorie restricted diet consisting of alternating periods of 50 percent calorie restriction and 100 percent ad libitum diet, or a chronic calorie restricted diet consisting of 75 percent of the ad libitum diet.
The researchers found that mammary tumor incidence was significantly lower in the intermittent calorie restriction group (9.1 percent) compared to the chronic calorie restriction group and ad libitum group (35.4 and 71 percent, respectively). They suggested that intermittent calorie restriction helped prevent breast cancer because reduced insulin-like growth factor-1 levels during the periods when the mice ate only 50 percent of their usual diet helped suppress cancer cell proliferation.
"Severe macronutrient restriction is likely an impractical cancer-control strategy," states the author of an accompanying editorial. "An area that deserves investigation, however, is pharmacologic interventions that mimic endocrine effects that mediate the benefits of dietary restriction. The possibility of developing 'caloric restriction mimetics' has been explored in longevity research because it is known that modest caloric restriction extends life expectancy in animal models. It now deserves rigorous study in the specific contexts of cancer prevention and treatment."