High breast density is known to be associated with an increased risk of breast cancer. New research demonstrates dietary factors in adolescence that might lead to higher-density breasts in adulthood. If the results are confirmed, the dietary habits of teenagers could potentially increase their chance of breast cancer decades later.
There are a number of known risk factors for breast cancer, including early onset periods, late menopause, and having the first child over the age of 30.
Studies show that dense breasts also increase the likelihood of breast cancer. The reasons for this link are not yet known.
Breast density refers to breasts that have a relatively high volume of fibrous or glandular tissue compared with fat.
Contrary to popular belief, breast density can not be judged by how a breast
Researchers Seungyoun Jung and Prof. Joanne Dorgan, from the Department of Epidemiology and Public Health at the University of Maryland School of Medicine, set out to investigate dietary factors that might influence the density of breast tissue.
The breasts are most sensitive to external factors during adolescence. This is a time when they are developing and undergoing structural change. As such, the team concentrated their focus on this pivotal stage of development into womanhood.
The researchers used data from the Dietary Intervention Study in Children (DISC). DISC was a clinical trial that started in 1988 and involved 301 girls aged 8-10 years. The study assessed the diets of these individuals across the following years.
During the DISC follow-up study, carried out when the participants were aged 25-29, the breast density of 177 women was measured using magnetic resonance imaging (MRI).
Before analyzing their results, Jung and Prof. Dorgan adjusted for an array of variables; these included number of live births, adult weight, race, education level, and total protein and energy intake.
Once these factors had been taken into account, the results showed that adolescents consuming higher quantities of saturated fat and a lower intake of mono- and polyunsaturated fats had an increased percentage of dense breast volume (DBV).
Women whose fat intake fell in the highest category had a mean DBV of 21.5 percent, whereas those in the lowest category had a mean DBV of 16.4 percent.
A similar, but opposite, effect was seen when the lowest and highest monounsaturated fat intake were compared; those consuming the least had the highest density breasts.
“[…] 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.”
Prof. Joanne Dorgan
The research does have a number of limitations, including the use of a comparatively small sample of predominantly Caucasian women; further investigation will be needed before the findings can be set in stone. However, if the results are backed up by further trials, the implications are serious.
Essentially, food items consumed as a teenager potentially increase the risk of breast cancer 15 years later.
High-fat diets are already known to produce other unwanted health outcomes, such as obesity, cardiovascular disease, and diabetes; breast cancer may eventually be added to that list.
On a positive note, these findings do provide a unique opportunity to prevent some cases of breast cancer. As Prof. Dorgan points out, “Our results are particularly interesting because diet during adolescence is modifiable, whereas most of the well-known risk factors for breast cancer, such as age at menarche and number and timing of pregnancies, offer little chance for intervention.”
The only other dietary factor that is known to increase breast cancer risk is high alcohol consumption during adulthood. Although the results could be construed as worrisome, the more information science has about breast cancer, the better armed researchers will be when investigating new treatments.