Fish oil preserves muscle and strength with aging, injury and post-surgery

Posted on: January 8th, 2025 by Our Team

In order of importance, the aspects of a person’s diet which affect growth of muscle are adequate calorie intake, followed by the quantity, quality and timing of protein consumption 4. Age is also a powerful driver, primarily due to anabolic resistance, which underpins much of age-related muscle loss. Anabolic resistance is an inability of muscle to mount the same response to a protein dose at a given meal, as well as to other anabolic stimuli such as resistance training.

It’s astonishingly easy to lose muscle during even brief inactive periods, such as those due to injury, illness or surgery. These events slow the rate at which we’re able to build new muscle. For this reason, proteins are the primary target for dietary intervention during periods of disuse. However, new research on fish oil as an alternative, anabolic agent has emerged over the last 5 years 2-3 9-11,specifically on essential fatty acids EPA (eicosapentaenoic acid) and DHA (docosa-hexaenoic acid).

Omega-3 fatty acids (or O3FA) are well-known anti-inflammatory agents which also support cardiovascular function, vision, joint and brain health. The first study to examine the impact of O3FA on muscle mass in response to a short period of physical inactivity was published five years ago1. Young, healthy women (under 31) had one leg immobilized in a knee brace for two weeks. Prior to immobilization, they supplemented daily with 5g of O3FA’s for 1 month, while the control group received sunflower oil.

Muscle protein synthesis was found to be significantly greater in the fish oil group throughout the study, enabling the women to fully retain their quadricep muscle mass and preserve greater muscle volume. The O3FA group lost half their muscle cross sectional area compared to control (a significant difference of 8% loss of volume vs. a 14% loss). These results demonstrate powerful, anti-catabolic properties of fish oil for even young people who are injured or or immobilized, such as with casting due to a fracture1.

Smith et al. led two similar randomized control trials in healthy, sedentary seniors taking a drug actually made of fish oil: Lovaza. In the first RCT, supplementation was given at the same dose approved by FDA for lowering plasma triglycerides (equivalent to 3.4g O3FA/day) for two months 2. O3FA’s significantly augmented the rate of muscle protein synthesis and attenuated anabolic resistance. Importantly, this study demonstrated that O3FA’s can be considered an effective therapy in treating sarcopenia- or functional loss of strength. This was the case even in the absence of any exercise program.

In their follow-up study, healthy seniors again took 4g/d Lovaza, this time for half a year 3. The fish-oil based drug showed clinically significant strength benefits, improving the senior’s handgrip, upper- and lower-body 1 rep max, as well as increasing thigh muscle volume. The difference between Lovaza and control was akin to preventing 2–3 years of age-predicted loss in muscle mass and function 3. Incredibly, these results were equal or greater than what has been achieved with testosterone and growth-hormone in older adults.

The exact mechanisms of O3FA are poorly understood. EPA and DHA incorporate into cell membranes where they influence phenotype, gene and protein expression 5-6. They also increase the transport of leucine within cells, and leucine is regarded as the only anabolic branched chain amino acid8. O3FA’s are also thought to make new mitochondria and stimulate proliferation of muscle cells8.

EPA and DHA are essential fats which must be consumed in the diet or via supplementation. So– why not just eat more fish? The most popular fish consumed in America are lean, and therefore low in O3FA’s. This means we’re not reaching the necessary levels in blood to have any therapeutic effect from diet alone. Recall that 5g/day is the anti-catabolic dose for young people1: to achieve this dose, we’d need to eat 1 pound of coho salmon every day. Other issues are mercury content in larger fish (like tuna) and oil rancidity / purity.

Nordic Naturals “Omega 2x” is a recommended fish oil brand (it is third party certified and in the well-absorbed, triglyceride form). Keep in mind that high-dose supplementation occurs in a dose-dependent manner (2.5 -5.0g/d) and that a minimum of 2-4 wks is necessary before muscle concentrations reach a therapeutic effect 6. If you are unable to move regularly due to injury or have a pending elective surgery, fish oil supplementation for one month prior to surgery, and for 2-3 months after- may help prevent muscle atrophy.

Contraindications. While O3FA’s can be safely consumed at doses up to 5g/day, doses above 6.4g/d have been reported to decrease blood clotting in healthy adults. For this reason, it’s advised to stop taking fish oil prior to any surgery, and to talk to your doctor before taking supplements if you’re on blood thinners (or blood pressure-lowering medications). Although belching is a benign side effect of fish oil due largely to its high fat content, high doses may trigger indigestion in those with GERD. Splitting doses into smaller portions throughout the day may help manage this.

References:

1. Mcglory et al. Omega-3 fatty acid supplementation attenuates skeletal muscle disuse atrophy during two weeks of unilateral leg immobilization in healthy young women. Faseb Journal. 10 January 2019.
2. Smith et al. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial. Am J Clin Nutr. 93:402. 2011
3. Smith, et al. Fish oil-derived n-3 PUFA therapy increases muscle mass and function in healthy older adults. Am. J. Clin. Nutr.102, 115–1228. 2015.
4. Witard, Oliver C. Growing older with health and vitality: a nexus of physical activity, exercise and nutrition.Biogerontology. 17:529–546. 2016.
5. Willis, Craig R. G. Transcriptomic links to muscle mass loss and declines in cumulative muscle protein synthesis during short-term disuse in healthy younger humans. FASEB journal, 2021.
6. McGlory et al. The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease. Frontiers in Nutrition. 06 September 2019.
7. Paoli et al. Not Only Protein: Dietary Supplements to Optimize the Skeletal Muscle Growth Response to Resistance Training: The Current State of Knowledge. Journal of Human Kinetics. Volume 91. 225–244. 2024.
8. McGlory et al. Temporal changes in human skeletal muscle and blood lipid composition with fish oil supplementation. Prostaglandins Leukot Essent Fatty Acids. 90:199–206. 2014
9. Brook and Matthew. Declines in muscle protein synthesis account for short-term muscle disuse atrophy in humans in the absence of increased muscle protein breakdown. 1,2 Journal of Cachexia, Sarcopenia and Muscle. 13. 2022
10. Rodacki, et al. Fish-oil supplementation enhances the effects of strength training in elderly women. Am. J. Clin.Nutr. 95, 428–4369. 2012.
11. Da Boit et al. Sex differences in the effect of fish-oil supplementation on the adaptive response to resistance exercise training in older people: a randomized controlled trial. Am. J. Clin. Nutr. 105, 151–158. 2017