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A diet rich in fruits, vegetables, and other high-fiber foods during adolescence and young adulthood is associated with women having a much lower risk of developing breast cancer, according to a study published Monday in Pediatrics.

Harvard researchers pulled data from more than 90,000 women who filled out questionnaires about their health back in 1991, when the women were between ages 27 and 44.

Circling back to those women recently, the researchers saw that breast cancer risk was between 12 and 19 percentage points lower among women who reported eating more dietary fiber in early adulthood.


And that risk changed based on fiber intake — for each additional 10 grams consumed a day, risk of developing breast cancer dropped 13 percent. A high-fiber diet during adolescence was also associated with a 24 percent lower risk of developing breast cancer before menopause.

The analysis controlled for other factors like race, family history of the cancer, and weight change over time. But studies like this come with several caveats. For one thing, the research is based on the women’s recollections of their diet as teens and young adults, and their memories could be faulty. For another, the correlation doesn’t necessarily prove a cause-and-effect finding.