Cutting down on processed meats and red meat cooked at high temperatures as well as high-fat diary products may help reduce a woman's risk of risk of developing breast cancer, hints results of a large study on diet and breast cancer.
Western-style diets have been linked to breast cancer, the study team notes in the American Journal of Clinical Nutrition, as have meat, eggs and dairy foods, but research on these dietary components and breast cancer risk has yielded inconsistent results.
Nearly all studies on the relationship, they add, have been done in populations where most people follow fairly similar eating patterns. This can mean that only the very strongest diet-disease links are identified.
To address this problem, the researchers looked at 367,993 women from 10 different European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. During follow-up, which averaged about nine years, 7,119 women were diagnosed with breast cancer.
While there were no consistent relationships between consumption of meat, eggs or dairy and breast cancer risk, the researchers did find a 10 percent increased risk among women who consumed the most processed meat, while heavy butter consumption boosted risk by 28 percent, but only in premenopausal women.
Risks associated with red meat eating varied country-by-country, with risks being greater in countries where cooking red meat at high temperatures was more popular.
"Our findings were not applicable to all the groups of women studied," study investigator Dr. Valeria Pala of Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, noted in an email to Reuters Health.
"Nevertheless, following the principle of caution, women should limit their consumption of processed meat and of red meat cooked at high temperature," Pala advised.
"Although we found that milk had no significant association with breast cancer," she added, "the direction of the milk-breast cancer relation changed with the fat content of the milk, suggesting a protective effect against breast cancer for skimmed milk, and increased risk for full-fat milk."
Based on other recent findings linking high saturated fat intake with greater breast cancer risk, she added, "it would be prudent to consume dairy products with reduced fat content."
In an editorial accompanying the study, Dr. Eleni Linos of Stanford University Medical Center in Redwood City, California, and Dr. Walter Willet of the Harvard School of Public Health in Boston say evidence is strong that eating animal foods in midlife or later does not have a "major effect" on breast cancer risk.
"Nevertheless, good reasons still exist for keeping consumption of red meat low, because this will likely help reduce risks of coronary heart disease and type 2 diabetes," they write.
There's also "solid evidence," they add, that avoiding weight gain in adulthood and limiting alcohol consumption can reduce breast cancer risk.