America's extreme "omega imbalance” is a threat to heart, brain, and immune health.

We coined that term as short-hand for the proportions of omega-3 and omega-6 fats in people's cells.

The evidence is very clear … diets with too few omega-3s and excess omega-6s raise your risk of brain, heart, and immune-related diseases.

People's diets should deliver no more than three omega-6s for every omega-3, but most Americans get 10 to 20 times more omega-6s than omega-3s.

To learn more about this critical but criminally neglected situation, see Know Your Omega-3/6 Numbers, America's Sickening Omega Imbalance, and the Omega-3 / Omega-6 Balance section of our news archive.

Growing research suggests that America's extreme omega-3/6 imbalance undermines breast health. 

For example, see Breast Cancer Tied to Omega Imbalance … Again, Omega-3s May Fight Breast Cancer Fatigue, Omega-3s May Curb Common Cancer Type, Omega-3s vs. Breast Cancer, and Fish Fats May Boost Breast Cancer Drug.

So it already seems clear that women should cut back on omega-6 fats and boost their omega-3 intakes to help deter this disease (and others).

(You will find the official U.S. and worldwide omega-3 intake guidelines on our Omega-3 Facts & Sources page.)

Before we describe the new study, let's review the background a bit.

Can omega-3s reduce breast cancer risk? The story so far
Lab studies show that omega-3s reduce tumor-fueling inflammation, increase apoptosis ("suicide”) in cancer cells, and slow tumor growth.

Conversely, excess intake of omega-6 fatty acids appears to fuel tumor growth … as does excess intake of refined sugars.

There are no clinical studies testing omega-3 supplements as a preventive aid against breast cancer, but there a quite a few epidemiological (diet-health) studies.

Epidemiological studies cannot prove a cause-effect relationship ... but they matter when the results of most align, and also enjoy supportive lab evidence.

Fish-source omega-3s enjoy ample lab evidence of anti-cancer effects, and most – though not all – epidemiological studies link fish-rich diets to lower risks for breast cancer.

Evidence that fish protects against breast cancer dates back at least 25 years, when Canadian researchers compared breast cancer rates with women's fish consumption: "… of the dietary components considered, percent calories from fish was the factor most strongly correlated with [lower] breast cancer rates.” (Kaizer L et al. 1989)

More recently, a review of the evidence from epidemiological studies linked diets rich in omega-3 fatty acids from seafood or fish oil to reduced risk: "Higher consumption of dietary marine omega-3 PUFA is associated with a lower risk of breast cancer.” (Zheng JS et al. 2013)

Very few epidemiological studies have examined whether higher omega-3 intakes lengthen survival after breast cancer diagnosis and treatment, and they've produced inconsistent results.

Now, the results of a long epidemiological study support the idea that diets high in omega-3s may help breast cancer patients survive longer.

Fish and omega-3s linked to longer survival after breast cancer
A study from the University of North Carolina links diets rich in omega-3s from fish or fish oil to reduced risk of early death among breast cancer patients (Khankari NK et al. 2015).

The UNC team analyzed data from a study conducted on Long Island, New York, which involved 1,463 women with breast cancer.

About three months after their diagnosis, the women were interviewed to determine their risk and prognostic factors, including diet.

The authors of the original Long Island study followed the women for an average of 14.7 years, during which time one in three (485) died, either from breast cancer or another cause.

For their analysis, the UNC researchers compared the women's diets to their health status after nearly 15 years.

And the results linked the highest intakes of seafood or fish oil to a substantial drop in the risk of death, compared with women who consumed little or no fish or omega-3 fish oil:
  • Highest Tuna Intake: 29 percent lower risk
  • Highest Omega-3 EPA Intake: 25 percent lower risk
  • Highest Omega-3 DHA Intake: 29 percent lower risk
  • Highest Fish (baked or broiled) Intake: 25 percent lower risk
Overall, deaths from any cause were reduced by 16 to 34 percent among women who reported high intakes of fish and/or omega-3s.

Wisely, the UNC team suggested that these findings should not just sit on a shelf.

As they wrote, "Long-chain omega-3 intake from fish and other dietary sources may provide a potential strategy to improve survival after breast cancer.”

We hope that journalists, doctors, authors, celebrities, and other opinion makers will spread the word ... far, wide, and fast.

  • Alfano CM, Imayama I, Neuhouser ML, Kiecolt-Glaser JK, Smith AW, Meeske K, McTiernan A, Bernstein L, Baumgartner KB, Ulrich CM, Ballard-Barbash R. Fatigue, inflammation, and ω-3 and ω-6 fatty acid intake among breast cancer survivors. J Clin Oncol. 2012 Apr 20;30(12):1280-7. doi: 10.1200/JCO.2011.36.4109. Epub 2012 Mar 12.
  • Bagga D, Anders KH, Wang HJ, Glaspy JA. Long-chain n-3-to-n-6 polyunsaturated fatty acid ratios in breast adipose tissue from women with and without breast cancer. Nutr Cancer. 2002;42(2):180-5.
  • Bagga D, Capone S, Wang HJ, Heber D, Lill M, Chap L, Glaspy JA. Dietary modulation of omega-3/omega-6 polyunsaturated fatty acid ratios in patients with breast cancer. J Natl Cancer Inst. 1997 Aug 6;89(15):1123-31.
  • Bakker N, Van't Veer P, Zock PL. Adipose fatty acids and cancers of the breast, prostate and colon: an ecological study. EURAMIC Study Group. Int J Cancer. 1997 Aug 7;72(4):587-91.
  • Bell GA, Kantor ED, Lampe JW, Kristal AR, Heckbert SR, White E. Intake of long-chain ω-3 fatty acids from diet and supplements in relation to mortality. Am J Epidemiol. 2014 Mar 15;179(6):710-20. doi: 10.1093/aje/kwt326. Epub 2014 Feb 3.
  • Caygill CP, Hill MJ. Fish, n-3 fatty acids and human colorectal and breast cancer mortality. Eur J Cancer Prev. 1995 Aug;4(4):329-32 Chajès V, Torres-Mejía G, Biessy C, Ortega-Olvera C, Angeles-Llerenas A, Ferrari P, Lazcano-Ponce E, Romieu I. ω-3 and ω-6 Polyunsaturated fatty acid intakes and the risk of breast cancer in Mexican women: impact of obesity status. Cancer Epidemiol Biomarkers Prev. 2012 Feb;21(2):319-26. doi: 10.1158/1055-9965.EPI-11-0896. Epub 2011 Dec 22.
  • Folsom AR, Demissie Z. Fish intake, marine omega-3 fatty acids, and mortality in a cohort of postmenopausal women. Am J Epidemiol. 2004 Nov 15;160(10):1005-10.
  • Goodstine SL, Zheng T, Holford TR, Ward BA, Carter D, Owens PH, Mayne ST. Dietary (n-3)/(n-6) fatty acid ratio: possible relationship to premenopausal but not postmenopausal breast cancer risk in U.S. women. J Nutr. 2003 May;133(5):1409-14.
  • Iyengar NM, Hudis CA, Gucalp A. Omega-3 fatty acids for the prevention of breast cancer: an update and state of the science. Curr Breast Cancer Rep. 2013 Sep 1;5(3):247-254.
  • Kaizer L, Boyd NF, Kriukov V, Tritchler D. Fish consumption and breast cancer risk: an ecological study. Nutr Cancer. 1989;12(1):61-8.
  • Khankari NK, Bradshaw PT, Steck SE, He K, Olshan AF, Shen J, Ahn J, Chen Y, Ahsan H, Terry MB, Teitelbaum SL, Neugut AI, Santella RM, Gammon MD. Dietary intake of fish, polyunsaturated fatty acids, and survival after breast cancer: A population-based follow-up study on Long Island, New York. Cancer. 2015 Mar 24. doi: 10.1002/cncr.29329. [Epub ahead of print]
  • Kim J, Lim SY, Shin A, Sung MK, Ro J, Kang HS, Lee KS, Kim SW, Lee ES. Fatty fish and fish omega-3 fatty acid intakes decrease the breast cancer risk: a case-control study. BMC Cancer. 2009 Jun 30;9:216. doi: 10.1186/1471-2407-9-216.
  • Maillard V, Bougnoux P, Ferrari P, Jourdan ML, Pinault M, Lavillonnière F, Body G, Le Floch O, Chajès V. N-3 and N-6 fatty acids in breast adipose tissue and relative risk of breast cancer in a case-control study in Tours, France. Int J Cancer. 2002 Mar 1;98(1):78-83.
  • McCann SE, Thompson LU, Nie J, Dorn J, Trevisan M, Shields PG, Ambrosone CB, Edge SB, Li HF, Kasprzak C, Freudenheim JL. Dietary lignan intakes in relation to survival among women with breast cancer: the Western New York Exposures and Breast Cancer (WEB) Study. Breast Cancer Res Treat. 2010 Jul;122(1):229-35. doi: 10.1007/s10549-009-0681-x. Epub 2009 Dec 22.
  • Patterson RE, Flatt SW, Newman VA, Natarajan L, Rock CL, Thomson CA, Caan BJ, Parker BA, Pierce JP. Marine fatty acid intake is associated with breast cancer prognosis. J Nutr. 2011 Feb;141(2):201-6. doi: 10.3945/jn.110.128777. Epub 2010 Dec 22.
  • Rose DP, Connolly JM, Rayburn J, Coleman M. Influence of diets containing eicosapentaenoic or docosahexaenoic acid on growth and metastasis of breast cancer cells in nude mice. J Natl Cancer Inst. 1995 Apr 19;87(8):587-92.
  • Saadatian-Elahi M, Toniolo P, Ferrari P, Goudable J, Akhmedkhanov A, Zeleniuch-Jacquotte A, Riboli E. Serum fatty acids and risk of breast cancer in a nested case-control study of the New York University Women's Health Study. Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1353-60.
  • Simonsen N, van't Veer P, Strain JJ, Martin-Moreno JM, Huttunen JK, Navajas JF, Martin BC, Thamm M, Kardinaal AF, Kok FJ, Kohlmeier L. Adipose tissue omega-3 and omega-6 fatty acid content and breast cancer in the EURAMIC study. European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Breast Cancer. Am J Epidemiol. 1998 Feb 15;147(4):342-52.
  • Wakai K, Tamakoshi K, Date C, Fukui M, Suzuki S, Lin Y, Niwa Y, Nishio K, Yatsuya H, Kondo T, Tokudome S, Yamamoto A, Toyoshima H, Tamakoshi A; JACC Study Group. Dietary intakes of fat and fatty acids and risk of breast cancer: a prospective study in Japan. Cancer Sci. 2005 Sep;96(9):590-9.
  • Zheng JS, Hu XJ, Zhao YM, Yang J, Li D. Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. BMJ. 2013 Jun 27;346:f3706. doi: 10.1136/bmj.f3706. Review.