Breast cancer is one of the most difficult cancers to prevent, in part because some of the most well known risk factors, such as the age at which a woman began her first period, are incapable of being treated or addressed. The disease is especially threatening without clear steps to take against it, but new research further supports the idea that dietary changes early in life may be one route toward prevention.
Adult alcohol consumption is currently the only dietary factor known to contribute to breast cancer, but some studies have suggested eating healthy during adolescence may also prevent the disease. A new study, published in Cancer Epidemiology, Biomarkers & Prevention, adds to this evidence; it discovered that consuming high amounts of saturated fat during adolescence, or low amounts of monounsaturated and polyunsaturated fats, may also increase risk by adding density to breast tissue.
“Breast tissue is most sensitive to exposures during adolescence, when breasts develop and undergo structural changes,” said the study’s leader, Seungyoun Jung, in a press release. Former studies have also linked high breast density to breast cancer, “so we set out to investigate whether fat intake during adolescence was associated with breast density in early adulthood.”
For the study, the researchers first analyzed the diets of young girls using records from the Dietary Intervention Study in Children (DISC), a health-based study conducted in 1988 that included 301 girls between the ages of 8 and 10. Then they followed up with 177 of those participants once they hit the ages of 25 to 29, and measured their breast density using magnetic resonance imaging (MRI).
After accounting for the girls’ race, education, weight, and number of births, the researchers discovered that a higher intake of saturated fat during adolescence, as well as a lower intake of monounsaturated and polyunsaturated fats during adolescence, was associated with a higher percent of dense breast volume (DBV) in early adulthood. Women who consumed the highest quantities of saturated fat, for example, had 21.5 percent of DBV on average, compared to 16.4 percent for women who consumed the least.
"The 5 to 6 percentage point difference in percent DBV is relatively modest, compared to the overall distribution of percent DBV observed in our study participants," said Jung, who is a fellow in the Department of Epidemiology and Public Health at the University of Maryland School of Medicine. Throughout their study, the researchers observed that DBV ranged from 9.7 percent to 41.2 percent.
Jung continued, "There is no clinical cut-point to define high versus low percent DBV to indicate women at increased risk of breast cancer. However, because there is a gradient of increasing breast cancer risk with increasing breast density, the differences in percent DBV we observed across extreme quartiles in our study, if confirmed, could potentially be of interest with regards to later breast cancer risk. ”
The researchers did note, however, that the results of their study are limited because they were unable to confirm whether the association between fat consumption and breast density was a direct link, or if the relationship was due to other components in foods with similar fat contents.
"If confirmed, the take-home message from our results is that diet consumed in early life is important and may confer chronic disease risk or protective benefits later in life,” Jung said. “In particular, the timing of dietary exposures might be important and appropriate dietary modifications during adolescence may potentially contribute to lowering breast density and consequently breast cancer risk as well as preventing obesity, diabetes, and cardiovascular disease."
Source: Jung S, et al. Cancer Epidemiology, Biomarkers & Prevention. 2016.