Teenage girls and young women who eat a high-fiber diet may reduce their risk of breast cancer later in life, according to a new study. The research, published online Feb. 1 in the journal Pediatrics, found that women who consumed the highest daily amount of fiber (28 grams) during high school had a significantly lower risk of breast cancer before menopause than those who at less fiber (15 grams).
“The results of this study emphasize the role of an early life high-fiber diet on prevention of breast cancer in later life. High consumption of foods rich in fiber, such as fruits, vegetables and whole grains in early life may help to reduce breast cancer incidence,” lead author Maryam Farvid, PhD, a visiting scientist at the Harvard T.H. Chan School of Public Health, told CBS News.
For the study, Farvid and her colleagues analyzed data from the Nurses’ Health Study II, which included 90,534 premenopausal women who completed a dietary questionnaire in 1991, when they were 27 to 44 years old. The women then responded to questions about their food intake every four years.
In 1999, 44,263 of the participants also answered a questionnaire about their diets when they were in high school. Over the next 20 years 1,118 women in the study were diagnosed with breast cancer.
Findings showed that overall, those who ate more dietary fiber when they were young were 12 percent to 19 percent less likely to develop breast cancer than those who ate less. Teens who ate more fiber experienced an overall lower risk of 16 percent and a 24 percent lower risk of getting breast cancer before menopause.
The research team also found that each additional 10 grams per day increase in fiber intake – including such foods as apples, pears, raspberries, peas, broccoli, lentils, whole wheat bread and pasta, bran flakes and oatmeal – during adolescence reduced the risk of breast cancer by 14 percent. “And getting the recommended 25 to 30 grams per day would decrease breast cancer risk by 30 percent,” Farvid told Reuters Health.
As for how a high-fiber diet works to prevent breast cancer, the researchers theorize high-fiber foods may lessen the risk in part by helping to reduce high estrogen levels in the blood, which is strongly linked with the development of breast cancer. In addition the authors noted high-fiber foods contain other nutrients, which could play a role in reducing the risk.
Though Farvid and her team acknowledge that further studies are needed, they see the study as a good indicator of an association between early life diet and a reduced risk of breast cancer.
“From other studies we know that breast tissue is particularly influenced by carcinogens and anti-carcinogens during childhood and adolescence,” senior author Walter Willett, MD, Fredrick John Stare Professor of Epidemiology and Nutrition at the Harvard T.H. Chan School of Public Health, said in a news release. “We now have evidence that what we feed our children during this period of life is also an important factor in future cancer risk.”