Want to lower your risk of developing breast cancer? Eat more fiber. According to a new study published in Pediatrics journal, eating a high-fiber diet while you’re in high school could significantly reduce your risk of breast cancer later in life. The study, sponsored by the Harvard T.H. Chan School of Public Health, found that women who ate high-fiber diets lowered their risk of cancer by 12-19%, proportional to their fiber intake. Because breast cancer is known to be linked to sex steroid hormone levels, and fiber inhibits reabsorption of estrogen, the fiber prevents too much estrogen from circulating in your bloodstream, therefore lowering your sex steroid hormone levels.
The researchers behind the study say another explanation for the results could be related to insulin sensitivity, because fiber helps to stabilize blood sugar levels. Previous studies have shown that fiber can help prevent colorectal and ovarian cancer, diabetes, and heart disease, and also manage your weight, but according to NPR this study is the first to link eating fiber to preventing breast cancer.
Maryam Farvid, the lead researcher, told NPR that your teenage years are "a period when breast cancer risk factors appear to be particularly important." Farvid told CBS News that “each additional 10 grams per day increase in fiber intake during adolescence reduced the risk of breast cancer by 14 percent.” The study itself cites young people exposed to radiation from the atomic bomb in Hiroshima developing cancer later in life as an example that "breast tissue may be particularly susceptible to carcinogenic exposures during childhood and early adult life." And, because the study is largely based around middle-age women remembering what they ate in high school, there’s a chance the results could be skewed.
But given the scope of the project – and the sample of 44,000 women – the results are still significant. What’s more important, though, is how we apply the results. Even teens who think they eat well probably aren’t getting the 28 grams per day necessary to reduce cancer risk. Eating foods like nuts, beans, quinoa, and raw fruits and vegetables can never be a bad thing, but it’s especially beneficial while we’re still young. So want to lower your risk of cancer, diabetes, and heart disease when you get older? Start eating more fiber.
By Kate Dwyer