Flaxseed May Impact Your Gut in a Way That Lowers Breast Cancer Risk, According to New Study

Flaxseed is packed with nutrients, including omega-3 fatty acids, fiber, vitamins, and minerals. Owing in part to this, it’s classified as a “superfood.” Research has linked its consumption with lower blood pressure, a reduction in menopause symptoms, and possible protective effects against breast cancer. A new study investigated that last point further, finding that something within flaxseed may help alter the gut microbiome and, by extension, lower breast cancer risk.

Research recently published in Microbiology Spectrum, a journal of the American Society for Microbiology, looked into how the gut microbiome is linked with breast health. To do this, they investigated the impacts of lignans – a flaxseed component – on the microbiota of female mice.

According to the findings, lignans influenced how gut microorganisms impact the expression of mammary gland microRNAs (miRNAs). A portion of these microRNAs regulate genes involved in breast cancer, including those that control cell proliferation and migration. This research showed that the flaxseed lignans changed the relationship between the gut and microRNAs to be non-cancer causing.

Dr. Jennifer Auchtung, assistant professor at the University of Nebraska-Lincoln’s Food Science and Technology Department, and editor who coordinated the paper’s review, says, “The gastrointestinal microbiota plays an important role in modifying many components of our diet to impact human health. In this study, we found correlations between diets enriched in flaxseed, cecal microbiota composition and miRNA profiles in the mammary gland that regulate many pathways, including those involved in cancer development. This preliminary study supports further research into the role that the microbiota plays in dietary approaches to reduce risk factors associated with disease.”

The findings still need to be confirmed, but they back other research, including a 2018 literature review showing that in animals, flaxseed paired with the hormone therapy tamoxifen can reduce tumor size better than tamoxifen alone. The review also noted that several clinical trials have found flaxseed can lower breast cancer risk, particularly in post-menopausal women.

Between these findings and the nutrients it contains, you may feel like increasing flaxseed’s presence in your diet. You can do so in a variety of ways, from adding it to baked goods, to sprinkling it on your salad, to adding it to a smoothie.