Do seafood-source omega-3s help protect against prostate cancer?

Most of the published studies suggest that omega-3s tend to curb the growth of prostate tumors.

For example, see Positive Omega-3/Prostate Trial, and the links it contains.

But in 2013, publication of a scientifically dubious study caused some men to stop taking omega-3 fish oil supplements (see Fishy Prostate News).

For that study, Ohio State University researchers analyzed data from the Selenium and Vitamin E Cancer Prevention Trial or SELECT (Brasky TM et al. 2013).

Their analysis showed that the men with the highest blood levels of seafood-source omega-3s were more likely to develop prostate cancer.

But experts dismissed those conclusions, because, among other reasons, the Ohio State team failed to properly account for major risk factors.

(Its other flaws are covered in the “Seven reasons for deep skepticism” section of our Fishy Prostate News article).

As prostate-cancer expert Professor Anthony D'Amico, M.D., of Harvard Medical School said in an interview, “… they left out some very important risk factors ... [which] makes this association extremely weak and possibly false.”

And, soon after the Ohio State paper caused undue concern, more evidence appeared suggesting that omega-3s can help curb prostate cancer: see Omega-3 Diet Reduced Prostate Risk Factors and Omega-3 Curbed Prostate Cancer Growth.

Studies have revealed several ways in which omega-3s should discourage cancer growth ... and a recent study found they possess a previously unknown prostate-protective property (Galet C et al. 2013).

Now, researchers have found yet another way in which omega-3s may curb the growth and spread of prostate cancer.

Study finds omega-3s may inhibit prostate cancer by a novel method
The new lab study was led by Professor Kathryn Meier, Ph.D., from the Washington State University College of Pharmacy (Liu Z et al. 2015).

Working with prostate cell cultures, Meier and two students found that omega-3 fatty acids bind to a cell-surface receptor called FFA4 (free fatty acid receptor 4).

The FFA4 receptor acts as a signal to inhibit tumor growth factors, thereby slowing the progression of prostate cancer.

“This kind of knowledge could lead us to better treat or prevent cancer," Meier said.

It's yet to be proven that fish or omega-3 fish oils can produce and maintain this specific anti-cancer effect in people.

And, the WSU study suggests that stimulation of the FFA4 receptor must be continuous ... while the effect of dietary omega-3s (from fish or fish oil) on the receptor may fade after they're fully metabolized.

So it seems urgent to discover whether consuming fish or omega-3 fish oil daily might affect the receptor enough to help curb cancer in people.

Most prostate cancers grow very slowly ... so any food factors that can help slow tumor growth could make a big difference to rates of diagnosis and death.

  • Aronson WJ, Barnard RJ, Freedland SJ, Henning S, Elashoff D, Jardack PM, Cohen P, Heber D, Kobayashi N. Growth inhibitory effect of low fat diet on prostate cancer cells: results of a prospective, randomized dietary intervention trial in men with prostate cancer. J Urol. 2010 Jan;183(1):345-50. doi: 10.1016/j.juro.2009.08.104. Epub.
  • Aronson WJ, Glaspy JA, Reddy ST, Reese D, Heber D, Bagga D. Modulation of omega-3/omega-6 polyunsaturated ratios with dietary fish oils in men with prostate cancer. Urology. 2001 Aug;58(2):283-8.
  • Aronson WJ, Kobayashi N, Barnard RJ, Henning S, Huang M, Jardack PM, Liu B, Gray A, Wan J, Konijeti R, Freedland SJ, Castor B, Heber D, Elashoff D, Said J, Cohen P, Galet C. Phase II prospective randomized trial of a low-fat diet with fish oil supplementation in men undergoing radical prostatectomy. Cancer Prev Res (Phila). 2011 Dec;4(12):2062-71. doi: 10.1158/1940-6207.CAPR-11-0298. Epub 2011 Oct 25.
  • Azrad M, Demark-Wahnefried W. Dietary omega-6 and omega-3 fatty acids and prostate cancer - letter. Cancer Prev Res (Phila). 2012 May;5(5):798; author reply 799. doi: 10.1158/1940-6207.CAPR-12-0032. Epub 2012 Apr 3.
  • Brasky TM, Darke AK, Song X, Tangen CM, Goodman PJ, Thompson IM, Meyskens FL Jr, Goodman GE, Minasian LM, Parnes HL, Klein EA, Kristal AR. Plasma phospholipid fatty acids and prostate cancer risk in the SELECT trial. J Natl Cancer Inst. 2013 Aug 7;105(15):1132-41. doi: 10.1093/jnci/djt174. Epub 2013 Jul 10.
  • Brasky TM, Till C, White E, Neuhouser ML, Song X, Goodman P, Thompson IM, King IB, Albanes D, Kristal AR. Serum phospholipid fatty acids and prostate cancer risk: results from the prostate cancer prevention trial. Am J Epidemiol. 2011 Jun 15;173(12):1429-39. doi: 10.1093/aje/kwr027. Epub 2011 Apr 24.
  • Chavarro JE, Stampfer MJ, Li H, Campos H, Kurth T, Ma J. A prospective study of polyunsaturated fatty acid levels in blood and prostate cancer risk. Cancer Epidemiol Biomarkers Prev. 2007 Jul;16(7):1364-70. Epub 2007 Jun 21.
  • Crowe FL et al. Fatty acid composition of plasma phospholipids and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr. 2008 Nov;88(5):1353-63.
  • Demark-Wahnefried W et al. Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery. Cancer Epidemiol Biomarkers Prev. 2008 Dec;17(12):3577-87. doi: 10.1158/1055-9965.EPI-08-0008.
  • Eser PO, Vanden Heuvel JP, Araujo J, Thompson JT. Marine- and plant-derived ω-3 fatty acids differentially regulate prostate cancer cell proliferation. Mol Clin Oncol. 2013 May;1(3):444-452. Epub 2013 Feb 15.
  • Galet C, Gollapudi K, Stepanian S, Byrd JB, Henning SM, Grogan T, Elashoff D, Heber D, Said J, Cohen P, Aronson WJ. Effect of a Low-Fat Fish Oil Diet on Proinflammatory Eicosanoids and Cell-Cycle Progression Score in Men Undergoing Radical Prostatectomy. Cancer Prev Res (Phila). 2013 Dec 19. [Epub ahead of print]
  • Gann PH et al. 1994; Godley PA et al. 1996; Harvei S et al. 1997; Newcomer LM et al. 2001; Männistö S et al. 2003; Laaksonen DE et al. 2004; Chavarro JE et al. 2007; Ukoli FA et al. 2009
  • Gann PH, Hennekens CH, Sacks FM, Grodstein F, Giovannucci EL, Stampfer MJ. Prospective study of plasma fatty acids and risk of prostate cancer. J Natl Cancer Inst. 1994 Feb 16;86(4):281-6. Erratum in: J Natl Cancer Inst 1994 May 4;86(9):728.
  • Godley PA, Campbell MK, Gallagher P, Martinson FE, Mohler JL, Sandler RS. Biomarkers of essential fatty acid consumption and risk of prostatic carcinoma. Cancer Epidemiol Biomarkers Prev. 1996 Nov;5(11):889-95.
  • Harvei S, Bjerve KS, Tretli S, Jellum E, Robsahm TE, Vatten L. Prediagnostic level of fatty acids in serum phospholipids: omega-3 and omega-6 fatty acids and the risk of prostate cancer. Int J Cancer. 1997 May 16;71(4):545-51.
  • Harvei S, Bjerve KS, Tretli S, Jellum E, Robsahm TE, Vatten L. Prediagnostic level of fatty acids in serum phospholipids: omega-3 and omega-6 fatty acids and the risk of prostate cancer. Int J Cancer. 1997 May 16;71(4):545-51.
  • Hudson BD, Shimpukade B, Mackenzie AE, Butcher AJ, Pediani JD, Christiansen E, Heathcote H, Tobin AB, Ulven T, Milligan G. The pharmacology of TUG-891, a potent and selective agonist of the free fatty acid receptor 4 (FFA4/GPR120), demonstrates both potential opportunity and possible challenges to therapeutic agonism. Mol Pharmacol. 2013 Nov;84(5):710-25. doi: 10.1124/mol.113.087783. Epub 2013 Aug 26.
  • Kelavkar UP, Hutzley J, Dhir R, Kim P, Allen KG, McHugh K. Prostate tumor growth and recurrence can be modulated by the omega-6:omega-3 ratio in diet: athymic mouse xenograft model simulating radical prostatectomy. Neoplasia. 2006 Feb;8(2):112-24.
  • Kobayashi N et al. Effect of altering dietary omega-6/omega-3 fatty acid ratios on prostate cancer membrane composition, cyclooxygenase-2, and prostaglandin E2. Clin Cancer Res. 2006 Aug 1;12(15):4662-70.
  • Laaksonen DE, Laukkanen JA, Niskanen L, Nyyssönen K, Rissanen TH, Voutilainen S, Pukkala E, Hakkarainen A, Salonen JT. Serum linoleic and total polyunsaturated fatty acids in relation to prostate and other cancers: a population-based cohort study. Int J Cancer. 2004 Sep 1;111(3):444-50.
  • Leitzmann MF, Stampfer MJ, Michaud DS, Augustsson K, Colditz GC, Willett WC, Giovannucci EL. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr. 2004 Jul;80(1):204-16.
  • Liu Z, Hopkins MM, Zhang Z, Quisenberry CB, Fix LC, Galvan BM, Meier KE. Omega-3 fatty acids and other FFA4 agonists inhibit growth factor signaling in human prostate cancer cells. J Pharmacol Exp Ther. 2015 Feb;352(2):380-94. doi: 10.1124/jpet.114.218974. Epub 2014 Dec 9.
  • Männistö S, Pietinen P, Virtanen MJ, Salminen I, Albanes D, Giovannucci E, Virtamo J. Fatty acids and risk of prostate cancer in a nested case-control study in male smokers. Cancer Epidemiol Biomarkers Prev. 2003 Dec;12(12):1422-8.
  • Milligan G, Alvarez-Curto E, Watterson KR, Ulven T, Hudson BD. Characterising pharmacological ligands to study the long chain fatty acid receptors GPR40/FFA1 and GPR120/FFA4. Br J Pharmacol. 2014 Aug 18. doi: 10.1111/bph.12879. [Epub ahead of print]
  • Newcomer LM, King IB, Wicklund KG, Stanford JL. The association of fatty acids with prostate cancer risk. Prostate. 2001 Jun 1;47(4):262-8. Pandalai PK, Pilat MJ, Yamazaki K, Naik H, Pienta KJ. The effects of omega-3 and omega-6 fatty acids on in vitro prostate cancer growth. Anticancer Res. 1996 Mar-Apr;16(2):815-20.
  • Terry PD, Rohan TE, Wolk A. Intakes of fish and marine fatty acids and the risks of cancers of the breast and prostate and of other hormone-related cancers: a review of the epidemiologic evidence. Am J Clin Nutr. 2003 Mar;77(3):532-43. Review.
  • Ukoli FA, Akumabor PN, Oguike TC, Dent LL, Beech D, Osime U. The association of plasma fatty acids with prostate cancer risk in Nigerians. Ethn Dis. 2009 Autumn;19(4):454-61.
  • University of California - Los Angeles Health Sciences (UCLAHS). Men with prostate cancer who ate a low-fat fish oil diet showed changes in their cancer tissue. November 18, 2013. Accessed at /uoc--mwp111813.php
  • Washington State University (WSU). WSU researchers show how fatty acids can fight prostate cancer. March 18, 2015. Accessed at /2015-03/wsu-wrs031715.php