How Much Fish Should We Eat?

How Much Fish Should We Eat?

It looks like 7.5 and 15 ounces per week of fish is protective against all-cause mortality [1-3] and the most recent dietary guidelines recommend consuming at least 8 ounces of fish per week [4].

The graphic below can be quite helpful.

Given the current evidence two meals per week of fish seems like a good play. 

Fish contains lots of essential vitamins (vitamin D, B vitamins, and choline) and minerals (iron, zinc, iodine, magnesium, and potassium), but fish are most known for containing longer forms of Omega 3 fatty acids which we can’t really get in large quantities from any other food source.

Omega 3 and Omega 6 fatty acids are essential. This means that humans cannot make them. 

There is a lot of biochemistry and it gets complicated, but humans can’t really convert* the type of Omega 3s that are say found in walnuts (ALA) into the longer Omega 3s that are found in fish (EPA and DHA) [5, 6].

In randomized controlled trials longer chain Omega 3s have been found to lower inflammation [7], reduce central adiposity [8], lower triglyceride levels [9], increase insulin sensitivity [10], lower blood pressure [11], potentially improve sleep [12], and reduce symptoms of depression [13], while the any direct effect on plasma lipids seems to be slight and variable [14, 15] .

Recent meta-analyses looking at fish oil and the potential impact on major cardiovascular events have found no association [16, 17], while others have found a small but significant reduction [9, 18-20]. 

Additionally, Omega 3s have been found to reduce cortisol [21], potentially improve recovery and body composition [22, 23], as well as increase muscle protein synthesis through the elevated activation of MTOR (whether this acute finding translates into adaptive changes in muscle mass long-term is currently unknown) [24, 25].

That's a lot of stuff!!

Given the totality of the evidence 1.5 to 3 grams of EPA + DHA per day seems like a solid idea [26-28] ** and a 5 ounce portion of cooked salmon contains roughly 3 grams of EPA + DHA and farmed salmon may have less contaminants and persistent organic pollutants [29-31].

If you don't like fish or don't want to eat it that frequently, our fish oil Omega EPA/DHA 1600 contains 1.6 grams of EPA and DHA in every two soft gels and includes vitamin E isomers (as DeltaGold® delta and gamma tocotrienols), which protect these fragile oils from oxidation and rancidity. Our fish oil is also molecularly distilled and filtered to ensure purity and to maximize the removal of metals, pesticides, PCBs, and other contaminants. Unfortunately, many fish oil supplements contain low amounts of EPA and DHA and high amounts of contaminants, while 10-20% of fish oil supplements may even be rancid [32-35].

#GIVEAFIT

*The conversion rate from ALA to EPA is likely less than 8% and the conversion to DHA less than 4% in males and this may go up slightly in females.

** As discussed in this article there are a plethora of potential positives from taking fish oil and very few potential negatives (reduction in blood clotting, possible GI distress, increased risk of arrhythmias) and the tolerable upper limit for DHA and EPA has been thought to be around 5 grams [36].

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

REFERENCES:

1. Zhao, L.G., et al., Fish consumption and all-cause mortality: a meta-analysis of cohort studies. Eur J Clin Nutr, 2016. 70(2): p. 155-61.

2. Shao, M.Y., et al., Association of fish consumption with risk of all-cause and cardiovascular disease mortality: an 11-year follow-up of the Guangzhou Biobank Cohort Study. Eur J Clin Nutr, 2021.

3. Jayedi, A., et al., Fish consumption and risk of all-cause and cardiovascular mortality: a dose-response meta-analysis of prospective observational studies. Public Health Nutr, 2018. 21(7): p. 1297-1306.

4. USDA, Dietary Guidelines for Americans 2020-2025. 2021: USDA.

5. Burns-Whitmore, B., et al., Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration? Nutrients, 2019. 11(10).

6. McGlory, C., P.C. Calder, and E.A. Nunes, The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease. Front Nutr, 2019. 6: p. 144.

7. Xin, W., W. Wei, and X. Li, Effects of fish oil supplementation on inflammatory markers in chronic heart failure: a meta-analysis of randomized controlled trials. BMC Cardiovasc Disord, 2012. 12: p. 77.

8. Du, S., et al., Does Fish Oil Have an Anti-Obesity Effect in Overweight/Obese Adults? A Meta-Analysis of Randomized Controlled Trials. PLoS One, 2015. 10(11): p. e0142652.

9. Khan, S.U., et al., Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis. EClinicalMedicine, 2021. 38: p. 100997.

10. Gao, H., et al., Fish oil supplementation and insulin sensitivity: a systematic review and meta-analysis. Lipids Health Dis, 2017. 16(1): p. 131.

11. Miller, P.E., M. Van Elswyk, and D.D. Alexander, Long-chain omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid and blood pressure: a meta-analysis of randomized controlled trials. Am J Hypertens, 2014. 27(7): p. 885-96.

12. Hansen, A.L., et al., Fish consumption, sleep, daily functioning, and heart rate variability. J Clin Sleep Med, 2014. 10(5): p. 567-75.

13. Appleton, K.M., et al., Omega-3 fatty acids for depression in adults. Cochrane Database Syst Rev, 2021. 11: p. CD004692.

14. Eslick, G.D., et al., Benefits of fish oil supplementation in hyperlipidemia: a systematic review and meta-analysis. Int J Cardiol, 2009. 136(1): p. 4-16.

15. Zhang, Y.Y., et al., Efficacy of Omega-3 Polyunsaturated Fatty Acids Supplementation in Managing Overweight and Obesity: A Meta-Analysis of Randomized Clinical Trials. J Nutr Health Aging, 2017. 21(2): p. 187-192.

16. Rizos, E.C., et al., Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. JAMA, 2012. 308(10): p. 1024-33.

17. Abdelhamid, A.S., et al., Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev, 2018. 7: p. CD003177.

18. Shen, S., et al., Omega-3 Fatty Acid Supplementation and Coronary Heart Disease Risks: A Meta-Analysis of Randomized Controlled Clinical Trials. Front Nutr, 2022. 9: p. 809311.

19. Balk, E.M. and A.H. Lichtenstein, Omega-3 Fatty Acids and Cardiovascular Disease: Summary of the 2016 Agency of Healthcare Research and Quality Evidence Review. Nutrients, 2017. 9(8).

20. Hu, Y., F.B. Hu, and J.E. Manson, Marine Omega-3 Supplementation and Cardiovascular Disease: An Updated Meta-Analysis of 13 Randomized Controlled Trials Involving 127 477 Participants. J Am Heart Assoc, 2019. 8(19): p. e013543.

21. Noreen, E.E., et al., Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults. J Int Soc Sports Nutr, 2010. 7: p. 31.

22. Crestani, D.M., et al., Chronic supplementation of omega-3 can improve body composition and maximal strength, but does not change the resistance to neuromuscular fatigue. Sport Sciences for Health, 2017. 13(2): p. 259-265.

23. Lewis, N.A., et al., Are There Benefits from the Use of Fish Oil Supplements in Athletes? A Systematic Review. Adv Nutr, 2020. 11(5): p. 1300-1314.

24. Smith, G.I., et al., Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women. Clin Sci (Lond), 2011. 121(6): p. 267-78.

25. Smith, G.I., et al., Fish oil-derived n-3 PUFA therapy increases muscle mass and function in healthy older adults. Am J Clin Nutr, 2015. 102(1): p. 115-22.

26. Mollica, M. Fish Oil For Fat Loss. 2013; Available from: http://www.theissnscoop.com/fish-oil-for-fat-loss/.

27. Gammone, M.A., et al., Omega-3 Polyunsaturated Fatty Acids: Benefits and Endpoints in Sport. Nutrients, 2018. 11(1).

28. Thielecke, F. and A. Blannin, Omega-3 Fatty Acids for Sport Performance-Are They Equally Beneficial for Athletes and Amateurs? A Narrative Review. Nutrients, 2020. 12(12).

29. Sprague, M., J.R. Dick, and D.R. Tocher, Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006-2015. Sci Rep, 2016. 6: p. 21892.

30. Jensen, I.J., et al., An Update on the Content of Fatty Acids, Dioxins, PCBs and Heavy Metals in Farmed, Escaped and Wild Atlantic Salmon (Salmo salar L.) in Norway. Foods, 2020. 9(12).

31. Lundebye, A.K., et al., Lower levels of Persistent Organic Pollutants, metals and the marine omega 3-fatty acid DHA in farmed compared to wild Atlantic salmon (Salmo salar). Environ Res, 2017. 155: p. 49-59.

32. Smutna, M., et al., Fish oil and cod liver as safe and healthy food supplements. Neuro Endocrinol Lett, 2009. 30 Suppl 1: p. 156-62.

33. Rawn, D.F., et al., Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides. J Food Sci, 2009. 74(1): p. T14-9.

34. Revealed: many common omega-3 fish oil supplements are ‘rancid’. 2022: The Guardian

35. Albert, B.B., et al., Fish oil supplements in New Zealand are highly oxidised and do not meet label content of n-3 PUFA. Sci Rep, 2015. 5: p. 7928.

36. EFSA Panel on Dietetic Products, N. and Allergies, Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). EFSA Journal, 2012. 10(7): p. 2815.