A recent study suggests that early adoption of healthy eating habits affects breast cancer risk later in life. Most notably, when adolescents and young adults had a high fibre diet, it was related to decreased breast cancer risk in mid life or later. Possible reasons include that a high fibre diet may inhibit the re-absorption of estrogen in the bloodstream causing decreased circulating levels.
The diet of 90534 women between the ages of 27 to 44 was first measured in 1991 using a diet questionnaire. During the 20 year follow-up that ended in 2011, 2833 women were diagnosed with invasive breast cancer. In 1998, 44263 women completed and returned a supplementary diet questionnaire focusing on high school diet. They were 33 to 52 years of age by that time. Among the 44263 women with data on adolescent fibre intake, 1118 women were diagnosed with invasive breast cancer from 1998 to 2011.
Interestingly, women with high fibre diets during early adulthood or adolescence were less likely to be smokers and heavy drinkers. Even when other dietary factors and healthy eating habits were accounted for, high fibre diets in adolescence and early adulthood were related to lower breast cancer risk. The type of fibre ingested mattered as well. Fibres found in fruits and vegetables were associated with lower breast cancer risk.
These findings support the hypothesis that a diet rich in fibre reduces breast cancer risk particularly if consumption occurs in adolescence and early adulthood. These findings are also in keeping with the American Cancer Society guidelines which promote the consumption of foods rich in fibre such as fruits and vegetables and indicate the importance of adopting healthy food choices during adolescence and young adulthood.
Farvid MS, Eliassen AH, Cho E, Liao X, Chen WY, Willett WC. Dietary Fiber Intake in Young Adults and Breast Cancer Risk. Am Academy of Pediatrics. . 2015: