Scientists around the world are continuously investigating what foods, nutrients, and other factors may reduce or increase the risk of developing breast cancer. Here are just a few of their more recent findings.
Fish Oil Use Linked to Lower Risk of Breast Cancer A preliminary study involving over 35,000 postmenopausal women has found that taking fish oil supplements over an average of ten years was associated with a reduced risk of breast cancer. Researchers note that more studies are needed to confirm this potential benefit.
Reference: Cancer Epidemiol Biomarkers Prev. 2010 Jul;19(7):1696-708
High Vitamin D Levels Linked to Reduced Breast Cancer Risk Vitamin D has been gaining a lot of attention for its potential role in reducing the risk of many cancers, including breast cancer. In this 2010 case controlled study, researchers found that higher vitamin D3 blood levels were associated with a reduced risk of breast cancer. This was especially true for women under age 53. The authors of the study say that more trials are needed with vitamin D supplementation to confirm its benefits, but that maintaining adequate vitamin D levels should be encouraged.
Reference: Cancer Epidemiol Biomarkers Prev. 2010 Sep;19(9):2341-50
Vitamin D and Calcium May Offer Protection Researchers looked at 21 different studies investigating vitamin D intake or levels and their effect on breast cancer risk. After looking at all of the studies, they found that those with the highest blood levels of vitamin D enjoyed a 45% reduction in breast cancer risk compared to those with the lowest vitamin D levels. Those with the highest intake of calcium had a 19% reduction in risk. The authors of this study stated that there is strong evidence that vitamin D and calcium have a chemopreventive effect against breast cancer.
Reference: Breast Cancer Res Treat. 2010 Jun;121(2):469-77. Epub 2009 Oct 23
Higher Intake of Lycopene and Carotenoids from Diet May Lower Breast Cancer Risk. In this study, those with the highest intake of lycopene-the plant phytochemical that gives watermelon and tomatoes their color, had a 74% reduced risk of breast cancer compared to those with the lowest intakes. The highest intake for total carotenoids was associated with a 63% reduced risk of breast cancer. Carotenoid-rich foods include many fruits and vegetables that are yellow, orange, red, or dark green.
Reference: Asia Pac J Clin Nutr. 2007;16 Suppl 1:437-42.
Meats-n-Sweets Diet Raises Breast Cancer Risk A meat and dessert heavy diet may increase the risk of breast cancer, especially in post-menopausal women. A study involving Chinese women found there was a 90% increased risk of breast cancer in post-menopausal women eating the most meat and sweets. The researchers concluded that a “Western” meat-sweet diet, like what is more typical in the United States, increases breast cancer risk in post menopausal Chinese women.
Reference: Cancer Epidemiol Biomarkers Prev. 2007 Jul;16(7):1443-8. Epub 2007 Jul 10.
More Fiber Lowers Breast Cancer Risk A study involving almost 36,000 pre-and post menopausal women found that a higher dietary intake of fiber was associated with a significantly reduced risk of breast cancer in only younger pre-menopausal women. Young women consuming over 30 grams of fiber a day enjoyed a 52% reduced risk of breast cancer compared to women consuming less than 20 grams of fiber a day. Fiber from cereals appeared to be most protective, followed by fruit fiber.
Reference: Int J Epidemiol. 2007 Apr;36(2):431-8. Epub 2007 Jan 24.
So what can you take away from these studies? Some simple diet changes that every woman can make are to increase fruit and vegetable intake. Choose high fiber breakfast cereals, oatmeal, and whole grain breads and pastas over refined, white options. You don’t have to completely give up meat and sweets but do try to eat a few more vegetarian meals every week and save desserts, regular soda, and candy for occasional treats.
It may be a little early to run out and buy a bottle of fish oil supplements solely for breast cancer prevention, but if you are already taking them then you may be helping to reduce your future risk. Regarding vitamin D, aim for 1000-2000 IU/day via diet and supplements and try to get some sensible sun exposure a few times a week. Ask your healthcare provider to check your vitamin D levels with a 25-hydroxy-vitamin D test, a.k.a 25 (OH) D. If your levels are low then you and your healthcare provider can develop a plan to raise levels.
Megan Witt, RD, LD