"These studies highlight two very important points. First we all need to remember that there are really no such things as 'bad' foods. Second, observational studies that show associations between diet and health need to be considered with a proverbial grain of salt. These studies clearly provide additional and strong evidence that consumption of meat and dairy products by women does not, by itself, increase breast cancer risk. Further, moderate and mindful consumption of these foods can be very important in attaining optimal nutrition for most women who often do not consume sufficient iron and calcium," said Dr. Shelley McGuire, a spokesperson for the American Society for Nutrition.
The studies did not assess the relation between animal-food intake during early life and later breast cancer, a likely important piece of the puzzle.
Nonetheless, write the authors of an editorial: "These data are sufficient to exclude any major effect of consuming these foods during midlife or later on risk of breast cancer."
The findings of the three studies have been reported in The American Journal of Clinical Nutrition.