Teenage girls who eat a diet higher in nuts and fiber may reduce their risk of breast cancer as adults, according to a study conducted by researchers from Brigham and Women’s Hospital, Harvard Medical School and published in the journal Cancer Causes Control in March 2010.
The study was conducted as a follow-up of 29,480 women who had filled out a diet questionnaire while they were in high school in 1998. 10 years later, 682 of those women had been diagnosed with proliferative benign breast disease (BBD), also known as fibrocystic breast disease or fibroadenoma.
Benign breast lumps such as those tracked in this study increased women’s risk of later developing breast cancer anywhere from 30 to 1,300 percent. As breast cancer can take decades to develop, BBD is often considered one of the first warning signs.
The power of fiber
Consistent with prior studies conducted on adults, the researchers found that adolescents with the highest fiber intake were 25 percent less likely to develop proliferative BBD than those with the lowest fiber intake, even after adjusting for interference from other potential risk factors.
An earlier study, published in the American Journal of Clinical Nutrition, found that adult women with the highest fiber intake were 11 percent less likely to develop breast cancer than women with the lowest intake.
Although many foods are high in fiber, researchers in the adolescence study found that nuts were particularly protective. Teenagers who consumed two or more servings of tree nuts or peanuts each week were 36 percent less likely to develop proliferative BBD than those who consumed fewer than one serving per month.
“These findings support the hypothesis that dietary intake of fiber and nuts during adolescence influences subsequent risk of breast disease and may suggest a viable means for breast cancer prevention,” the researchers wrote.
Studies have also shown that women who consume more nuts and fiber live significantly longer than women who consume less.
The importance of prevention
Numerous studies have indicated that behaviors early in life can influence lifetime cancer risk. For example, excessive alcohol consumption in the teenage years has also been linked to later cancer risk. Referencing these findings, the researchers noted that teenage girls should not take high nut and fiber consumption as an excuse to drink more alcohol, as the two effects do not necessarily cancel each other out.
Breast cancer is the most common cancer and the most common cause of cancer death in women worldwide. Approximately one out of every eight U.S. women receives a breast cancer diagnosis each year. The cancer is fatal in 20 to 25 percent of cases.