Here's some verbal red meat for literal red meat haters and for cancer haters (which is all of us) -- a new study by the Harvard School of Public Health implicates red meat consumption, especially earlier in life, with an increased risk of breast cancer in women.
Basically, the study revealed that higher red meat intake in early adulthood may be a risk factor for breast cancer. However, replacing red meat with a combination of legumes, poultry, fish and nuts may reduce breast cancer risk.
It has been a common theory that overconsumption of protein- and fat-rich red meat is a contributory factor in many cancers, most notably colon, pancreas and prostate. Red meat is also in the mix for development of heart disease and diabetes. Processed red meats seem to be especially harmful.
The study's red meat items included unprocessed red meat (beef, pork, or lamb and hamburger) and processed red meat (hot dogs, bacon, sausage and similar). Poultry types consisted of chicken and turkey; fish included tuna, salmon, mackerel and sardines. Beans, lentils, peas and nuts predominated in the legumes group.
The study tracked a group of 88,803 pre-menopausal women (ages 26 to 45) over a 20-year period. In this group, women who had the highest consumption rate of red meat exhibited a 25 percent greater risk of breast cancer. Participants were pre-menopausal women who completed the Nurses' Health Study II diet questionnaire in 1991. At the end of the study period, 2,830 cases of reported invasive breast carcinoma were confirmed by pathology.
In post-menopausal women, higher intake of poultry was associated with a lower risk of breast cancer; a greater risk level was found for pre-menopausal women. Substituting one serving per day of legumes for one serving per day of red meat was associated with a 15 percent lower risk of breast cancer among all women, 19 percent lower with pre-menopausal women.
It is theorized that high protein intake may raise the risk of breast cancer by increasing the insulin-like growth factor that plays an important role in tissue growth and tumor progression.
Poultry in motion -- swapping the one serving/day of red meat in favor of poultry -- resulted in a 17 percent reduced risk of breast cancer; 24 percent lower for post-menopausal women. A combined daily serving of legumes, nuts, poultry and fish for the equal serving of red meat was figured at a 14 percent lower breast cancer risk overall.
Despite all of the data accumulated in this study, the authors also caution that other related studies taken as a whole do not suggest a significant association between red meat and breast cancer, as these studies were based on diet during midlife and greater. The Harvard Study differs in that it focuses on early adulthood dietary habits.