April 9, 2008 -- When it comes to breast cancer, a traditional Mexican diet may serve up an ounce of prevention for a variety of women.
A study involving hundreds of women living in the Four Corners region (Colorado, Utah, New Mexico, and Arizona) shows that a diet emphasizing Mexican cheeses, beans, soups, tomato-based sauces, and meat may help lower the risk of breast cancer in both Hispanic and non-Hispanic women.
Lower rates of breast cancer among Hispanic women than non-Hispanic white women prompted University of Utah scientist Maureen Murtaugh, PhD, RD, and colleagues to investigate whether their diets played a role in risk reduction, and how other factors influenced outcomes.
The team identified study participants as Hispanic or non-Hispanic white women and grouped them according to whether or not they had reached menopause. The women answered questions about the type and amount of foods they ate. Researchers grouped their findings according to five defined dietary patterns:
- Native Mexican diet: Soups, legumes, tomato-based sauces, meat dishes, and Mexican cheeses.
- Western diet: High-fat dairy, high-sugar, low-fiber foods including red meats, fast foods, and refined grains.
- Prudent diet: Low-fat dairy foods, whole grains, fruits, vegetables, and legumes.
- Mediterranean diet: Components of the prudent diet plus alcohol, chicken, and fish.
- Dieters: Low-calorie foods, low-fat foods, and avoidance of high-fat foods.
Diet and Breast Cancer Risk
The lowest risks of breast cancer appeared among those who closely followed the native Mexican or Mediterranean diets and were similar across ethnicity. But researchers caution that such diets are not one-size-fits-all. Body mass index and menopausal status influenced results.
Among the findings:
- The native Mexican diet decreased breast cancer risk as consumption increased, except those in the postmenopausal Hispanic group.
- The Mediterranean diet decreased breast cancer risk as consumption increased in postmenopausal Hispanic women.
- Among the women who followed a native Mexican diet before menopause, the greatest protective effect was seen in those with a body mass index lower than 25.
The Western (American) diet was associated with the greatest risk of breast cancer, regardless of menopausal status. The findings support earlier studies that such diets increase women's risk of breast cancer.
Surprisingly, Murtaugh's team found that women who followed the "prudent diet" also had a greater risk of breast cancer, a finding that contradicts results from three earlier studies. The reason for the difference is unclear. Murtaugh notes that further study needs to be done to assess this finding.