Alcohol can be a major risk factor for breast cancer but a 'healthy' or 'western' diet does not seem to have any adverse effect. These are the findings of a recent report in the journal Cancer Epidemiology, Biomarkers and Prevention reported by the American cancer Society.
Women who drink wine, beer or spirits increase their chances of getting breast cancer by about 30%, according to the report.
"Diet is one of many lifestyle factors that may be related to cancer," said Paul Terry, PhD, MPH, an epidemiologist at Albert Einstein College of Medicine in New York City and principal author of the report. "Some of the others include relative body weight and physical activity."
He added that women should realise that there are several forms of cancer, and what is a risk factor for one form might not be for another.
The 10-year study investigated more than 60,000 Swedish women, identifying their food and beverage preferences. Some women ate a 'western' diet, high in red meat, whole milk, white flour and snacks, while others ate a 'healthy' diet of whole grains, fruit, vegetables, fish, chicken and low-fat milk products. A third pattern also emerged - a so-called 'drinker' pattern with a high consumption of beer, wine and spirits.
"The results suggest that eating a 'western' or 'healthy' diet does not alter the risk for breast cancer," said Terry. "It is important to note that diet may not be related to breast cancer risk, but is certainly related to overall health."
Marji McCullough, ScD, RD, nutritional epidemiologist at the American Cancer Society (ACS), said that the study was consistent with previous epidemiological studies.
"They find that people who drink more have increased risk for breast cancer. Most studies have shown that alcohol has a stronger effect on post-menopausal breast cancer.
But she gave a word of warning about the study's findings on diet. "The study wasn't able to look at diet during younger years, which may be more relevant to breast cancer risk."
Both the researchers and the ACS agree that a good diet is important in fighting off cancer and other diseases such as heart disease. The most important ways to prevent breast cancer are to avoid becoming overweight, exercise moderately, avoid smoking and avoid alcohol, Terry said. "But a woman at high risk of breast cancer will still wish to eat healthy," he said. "It always pays off."
McCullough cautioned there is some overlap among the dietary patterns observed in this study. People in all three diet-pattern groups ate some whole grains. They all ate some red meat.
"This study looks at diet patterns that occurred naturally in a specific population," she said. "It doesn't tell you whether people who follow particular eating guidelines might be at lower risk for breast cancer."