Fish Oil Supplements May Reduce Breast Cancer Risk

Fish Oil Supplements May Reduce Breast Cancer Risk

Fish Oil Contains MercuryConsuming fish oil supplements may reduce your risk associated with breast cancer?  Well, don’t get too excited yet.  I just heard this story on the news yesterday and the news media are jumping all over it with a slightly one-sided view.

A recent study published in the journal, Cancer Epidemiology, Biomarkers & Prevention, suggests that fish oil consumption might be associated with a reduced risk of breast cancer.  Basically, the study authors asked just over 35,000 women to complete a 24 page baseline questionnaire regarding their recent and past use of speciality supplements, then analyzed this data with incident invasive breast cancer over the following 5-7 years.    Participants included in the study were postemenopausal women between 50-76 years of age.

These type of prospective studies are useful for finding further areas of research, but the results are not particularly robust.  The women in the study were also asked about their use of other supplements for menopause including black cohosh, dong quai, soy, and St. John’s wort.

What did the study authors find?

  • Current use of fish oil was associated with a 32% reduced risk of developing breast cancer
  • 10 year average use was suggestive of a possible reduced risk (p trend=0.09)
  • Use of black cohosh, donq quai, soy, and St. John’s wort were not associated with a reduced risk of breast cancer.

To start off with, this is just an epidemiological study not a randomized double-blind controlled trial, so further research is required to confirm these findings.  Worse yet, ten year average use was only suggestive of a reduced risk.  Researchers often cite statistical trends when the data doesn’t reach the level of statistical significance.  However, statistical trends are not really that meaningful.

Though there are many health benefits of consuming fish oil supplements (omega 3 fatty acids), one area of concern that you should be aware of is that some supplements are contaminated with orgnanic pollutants including mercury or PCBs.  As well, the data from this study does not provide any information on optimum dosage ranges.  More is not always better when it comes to supplements and your diet.

Other supplements that may reduce breast cancer risk?

  • Vitamin D
  • Folate, B12, and Vitamin B6


  1. Brasky TM, Lampe JW, Potter JD, Patterson RE, White E. Specialty Supplements and Breast Cancer Risk in the VITamins And Lifestyle (VITAL) Cohort.  Specialty Supplements and Breast Cancer Risk in the VITamins And Lifestyle (VITAL) Cohort.Cancer Epidemiol Biomarkers Prev. 2010 Jul;19(7):1696-708.
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