Written by Jessica Patella, ND. In a study with 250 women newly diagnosed with breast cancer and 250 controls, those consuming whole grains more than 7 times per week had only about 1/3 the breast cancer than in the low whole grain group.

Breast cancer is the second most common cancer in women, second to skin cancer (2). Breast cancer is also the second leading cause of death in women; lung cancer is the first (2). Eating whole grains has been associated with health benefits and research has now shown that eating whole grains is associated with a lower risk of breast cancer (1).

Whole grains are defined as intact, ground, cracked or flaked grains in which the entire part of the grain is present (bran, germ and endosperm) (1). Examples include: whole wheat, oats, brown rice, rye, barley, bulgur, buckwheat and quinoa (1).

The recent research included 250 females with a new diagnosis of breast cancer (56 +/-12 years) and 250 age-matched controls. All participants completed an 86-question food frequency questionnaire to determine how often they consumed the major food groups and beverages: “never/rarely”, “1-6 times/week” or “more than 7 times per week” (1).  Participants were also asked to recall their physical activity levels.

Overall, the following associations were observed:

  • Participants with breast cancer were more likely to be overweight
  • Participants with breast cancer consumed less whole grains compared with controls
  • Consuming whole grains more than 7 times per week was associated with a 0.4-fold lower risk of having breast cancer (OR=0.35; 95%CI, 0.23, 0.55; p<0.001)
  • Consuming whole grains 1-6 times per week was associated with a 0.6-fold lower risk of having breast cancer (OR=0.56; 95%CI, 0.36, 0.87; p=0.01)
  • Women who did NOT use Hormone Replacement Therapy and consumed whole grains 7 times per week or more were associated with a 0.54-fold lower risk of having breast cancer (OR=0.54; 95% CI 0.31, 0.93; p=0.026)

These findings show that eating whole grains more than 7 times per week was consistently associated with a lower risk for breast cancer (1). This association was especially strong for normal weight women and those who did not use Hormone Replacement Therapy (1).

The researchers thought this might be because whole grains provide fiber which increases transit time in the bowel, allowing for less mutations to occur (1). Another suggestion was that whole grains are rich in antioxidants which can decrease the risk of cancer (1).

In conclusion, the more whole grains consumed, the lower the risk for breast cancer (1). The limitation of the study was that all the participants were doing a dietary recall. Future studies should include a randomized clinical trial to confirm the results.

Source: Mourouti, Niki, et al. “Whole grain consumption and breast cancer: a case-control study in women.” Journal of the American College of Nutrition 35.2 (2016): 143-149.

Posted May 26, 2015.

Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health.  She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians.  Visit her website at  www.awarenesswellness.com.

References:

  1. Mourouti N, et al.  Whole Grain Consumption and Breast Cancer: A Case-Control Study in Women.  Journal of the American College of Nutrition.  DOI: 10.1080/07315724.2014.963899
  2. American Cancer Society.  Breast Cancer Statistics.