Fish Oil May Reduce Breast Risk

A new observational, population-based study has found that regular and long-term use of fish oil supplements may reduce the risk of breast cancer in postmenopausal women. While this study was widely reported in the mainstream news, the details were often wrong. Hopefully we can clarify the research for you below.

The study was conducted at the Fred Hutchinson Cancer Research Center in Seattle, Washington. The researchers noted that the purpose of the study was to evaluate the "use of nonvitamin, nonmineral 'specialty' supplements" and their effects, if any, on cancer rates.

The researchers noted that that "several supplements may have anti-inflammatory or anticancer properties. Additionally, supplements taken for symptoms of menopause have been associated with reduced risk of breast cancer in two case-control studies." To this end, the researchers analyzed data from 35,016 postmenopausal women from western Washington state, who were between 50 and 76 years of age at baseline, taken from 2000 to 2002. All the women were a part of the VITamins And Lifestyle (VITAL) Cohort and were followed until 2007. Women completed a 24-page baseline questionnaire that asked the women the recency (current versus past), frequency (days/week), and duration (years) of all specialty supplement use. This information was collected repeatedly through the duration of the study.

Over the course of the study, 880 cases of invasive breast cancer were diagnosed. The researchers found that women who were currently taking a fish oil supplement had a 32% reduced risk of developing breast cancer.

Likewise, the analysis of the 10-year average use also suggested a protective effect from past use, but as expected that relationship was not as strong as current use. Part of the reason this relationship may not have been as strong is because of the reporting method. People have a tendency to "over report" supplement use, reporting continuous, daily use, even though they may not have taken a supplement for months on end, or had only taken it intermittently.

According the the researchers, this is the first time that fish oil use has been linked to reduced breast cancer risk.

This study also examined a handful of other supplements that are sometimes taken for menopause symptoms: black cohosh, dong quai, soy, and St. John's wort. No relationship to breast cancer rates (positive or negative) could be identified--adding additional data to the long-term safety profile of these products.

Learn more about the potential benefits of omega-3 fatty acids here, and learn about our Omega-3 Fish Oil and Extra-Strength Omega-3 Fish Oil.

1. Brasky, T. M., J. W. Lampe, et al. (2010). "Specialty supplements and breast cancer risk in the VITamins And Lifestyle (VITAL) Cohort." Cancer Epidemiol Biomarkers Prev 19(7): 1696-708.