Dietary fiber has been shown to have a number of health benefits, including benefits for heart health and breast cancer risk reduction. Dietary fiber appears to benefit human health through multiple mechanisms. In relation to breast cancer, research suggests that dietary fiber might reduce breast cancer risk by modifying estrogen levels and reducing inflammation markers. However, the impact of dietary fiber on breast cancer subtypes are less clear.
A new breast cancer research study examined the potential relationship between dietary fiber intake and breast cancer by hormone receptor status and by different fractions of dietary fiber. The study investigators selected 438 women with breast cancer and 438 healthy women matched to the breast cancer patients by age and residential location. Dietary fiber intake was assessed in face-to-face interviews using a food frequency questionnaire and the relationship between dietary fiber consumption and breast cancer risk was analyzed. The breast cancer researchers reported
Compared to the lowest level of fiber consumption, high levels of total dietary fiber intake was linked to a 69% reduction in breast cancer risk.
In regards to dietary fiber fractions... breast cancer risk was reduced 27% by soy fiber intake, 52% by vegetable fiber consumption, and 46% by fruit fiber consumption.
A reduction in breast cancer risk with higher levels of dietary fiber intake was observed for ER[+], ER[-], ER[+]/PR[+], and ER[-]/PR[+] breast cancers.
These are very positive results for dietary fiber intake and breast cancer risk reduction. In addition to overall fiber intake reducing breast cancer risk, this new study specifies the importance of particular sources of dietary fiber. According to these results, both vegetable fiber and fruit fiber are particularly beneficial for reducing breast cancer risk, though soy fiber also showed a modest breast cancer risk reduction benefit. Despite these and previous results showing the health benefits of dietary fiber, less than half of Americans consume adequate amounts of dietary fiber (i.e. 25 - 35 grams per day). In addition to being good sources of fiber, fruits, vegetables, and soy are rich sources of natural plant chemicals with antioxidant and anti-inflammatory actions, which have been reported to have health benefits independent of these foods' fiber content. This new study continues to confirm the importance of eating plenty of fruits and vegetables and getting enough fiber every day. Are you getting as much as you should?