Fish oil for muscle gain?

Fish oil for muscle gain?


The use of fish oils by athletes is hardly new. Their widespread adoption follow the great deal of publicity they receive in both the fitness and mainstream media highlighting their benefits for everything from cardiovascular and joint health to their potential ability to improve body composition. For more details please see our article on essential fatty acids.

Instead of rehashing that article, I want to discuss today more recent research which suggests the potential for fish oils to enhance muscle growth. Intrigued? Read on.

The first two studies were conducted by the same researchers last year. The first (1) investigated the effects of Omega-3 supplementation (the fatty acids found in fish oils) among older adults to see if they could attenuate the decline in muscle mass seen with aged populations. Previous animal research (2) had supported the ability of Omega-3 supplements with respect to this role, as well as their ability to improve body composition (3). Subjects were split into a placebo group consuming corn oil and the Omega-3 group and took their supplements for eight weeks. The study measured the rate of both muscle protein synthesis and anabolic signalling pathways such as mTOR, before and after supplementation and measured these in both fasted conditions and after an infusion of amino acids and insulin. The reason for measuring in fasted conditions versus after a meal is because providing nutrients such as protein and BCAA’s to the body will enhance muscle protein synthesis of its own accord.

Results: As would be expected the corn oil had no effect on either muscle synthesis or anabolic signalling. Omega-3 supplementation did not impact fasted muscle protein synthesis levels but did enhance muscle protein synthesis after the amino acid/insulin infusion from 0.009 above basal values to 0.031 above basal values. This was coupled with greater anabolic signalling effects as evidenced by big increases in mTOR and p70s6k.

These results led the authors to conclude that omega-3 fatty acids stimulate muscle protein synthesis in older adults and can be useful as a treatment for age related loss of muscle.

The second study (4) began from the premise that while Omega-3 fatty acids could help limit loss of muscle in aged populations, its effects on muscle growth in younger subjects had yet to be established. This provided the impetus for the same team’s follow up study.

The researchers set up a simple study with nine participants (a little low in our view) and compared the effect on muscle protein synthesis and anabolic signalling pathways of eight weeks of Omega-3 fatty acid supplements using 4g of the pharmaceutical Omega-3 product Lovaza®. This totalled 1.86 of EPA and 1.5g of DHA daily which is a higher concentration of these two fatty acids than would be available in nutritional supplements, which would require a higher dose than 4g to achieve these levels of EPA and DHA.

As in their first study, the group measured muscle protein synthesis and anabolic signalling when fasted and during an infusion of amino acids and insulin.

Results: Similar to the study in older adults Omega-3 fatty acid supplementation had no effect on basal (fasted) rates of muscle protein synthesis or anabolic signalling pathways. Consider that beyond hormonal manipulation such as the use of prohormones or other supplements which can enhance testosterone, there is not much that will spike muscle growth in the absence of nutrients.

The study on older adults had a positive result on MPS and signalling pathways during the second measurement when the participants were provided amino acids. How would the second study compare?

Yet again the researchers discovered that the anabolic response to the infusion protocol was greater after Omega-3 supplementation with the average rate or muscle protein synthesis increasing from 0.062 to 0.083 and mTOR and p70s6k levels increased by 50%. The researchers also measured the muscle protein concentration and muscle cell size and both increased after Omega-3 fatty acid supplementation. The group concluded that the provision of Omega-3 fatty acids could have anabolic effects in younger people as well as older adults.

As far as looking at the potential benefits of fish oil supplementation, another recent study (5) underlined the potential body composition and muscle gain benefits for fish oil. Noreen et al compared the effects of supplementing the diet with either 4g/day of Safflower Oil, an Omega-6 fatty acid or 4g/day of fish oils comprising 1.6g of EPA and 0.8g of DHA. Note that this was less than in the two studies we looked at initially which showed positive muscle building effects for Omega-3 fatty acids.

The researchers showed that compared to the Safflower Oil group, the fish oil group gained a significant amount of fat free mass (0.5kg versus a 0.1kg loss) and a significant reduction in body fat (-0.5kg versus +0.2kg). Furthermore, body fat percentage for the fish oil group declined by 0.4% while for the safflower group it rose by 0.3%. To underline the value of fish oil supplementation the researchers in this study measured cortisol levels which also decreased in the group consuming fish oil and showed a strong correlation between the change in cortisol and change in fat free mass.

This group concluded that fish oil supplementation significantly increased lean mass and decreased fat.

Our Comments

These research studies have certainly generated a lot of interest in the field of nutrition and represent another feather in the cap for the benefits of Omega-3 fatty acid supplementation. The studies do present some interesting ideas for what we might consider an effective dose for omega-3 fatty acids.

Traditionally many nutritionists have cautioned against the oversupply of Omega-3 fatty acids and suggested that people instead seek to have a balance of Omega-3 and Omega-6 fatty acids based on the idea that as a species we would have evolved on a diet that had a roughly equal ratio of both (6). Set against this, the average western diet tends to provide an excess of Omega-6 fatty acids so in these circumstances it has always been our view that there is no need to provide additional Omega-6 fatty acids as seen in blends such as Udo’s Choice, as even if these are relatively higher in Omega-3 fatty acids they will still not be able to compensate fully the large disparity between Omega-3 and Omega-6 intakes from our diets.

Certainly while there is some evidence to show that high intakes can reduce immune system response (7), which can actually be good when treating certain condition, this is not something which was seen in younger men. If immunity is low and you struggle to combat illness then certainly you may want to think about striking a balance when dosing fish oil. In this study, there was a dose-dependent reduction in immune cell activity so keeping combined EPA/DHA intake below two would be a good compromise. Also, remember this one adverse effect has to be set against the glut of positive effects for Omega-3 fatty acids in doing everything from lowering stress, blood pressure and improving heart health, to improving mood, treating psychological disorders and enhancing body composition.

What should I take?

Based on the research, a dose of 2-4g a day of combined EPA and DHA will provide the necessary benefits for improving the potential for muscle gain. Unlike the study using Lovaza, achieving the same dose with fish oil supplements will require a higher dosage. Alternatively using a krill oil supplement would allow for lower dosing as krill oil has been shown in research to be more potent than fish oil although it has less research devoted to it at this stage. Something you may have been doing which we think is a poor strategy is to consume flax oil which gets converted into the body into alpha linolenic acid, an Omega-3 fatty acid but the poor conversion rate of flax oil to this makes it a poor choice for ensuring you meet your Omega-3 goals. Similarly, we hear of a lot of bodybuilders using cod liver oil which can be considered a poor man’s fish oil supplement. Cod liver oil tends to be lower in EPA and DHA content and the fact that it also is produced from the liver, an organ which deals with the job of detoxifying contaminants, makes us reluctant to recommend this practice. In addition, it contains vitamins A and D which may be too much if already supplementing these.

Whatever choice of product you use, we would suggest dosing the supplements with meals to avoid any gastric reflux issues and to enhance absorption.

Recommended Supplements

Krillipid Balance 60 Softgels

Ultra Omega 3 Fish Oils 180 Softgels

Triple Strength Fish Fats 60 Softgels



1.Smith GI (2011): Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial.

2. Gingras AA (2007): Long-chain omega-3 fatty acids regulate bovine whole-body protein metabolism by promoting muscle insulin signalling to the Akt-mTOR-S6K1 pathway and insulin sensitivity.

3. Su W (1993) Dietary fatty acid composition influences energy accretion in rats.

4. Smith GI (2011): Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women.

5. Noreen (2010): Effects of supplemental fish oil on resting metabolic rate, body composition, and salivary cortisol in healthy adults

6. Simopoulos AP (2002): The importance of the ratio of omega-6/omega-3 essential fatty acids.

7. Rees D, et al. Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men. Am J Clin Nutr. 2006 Feb;83(2):187-8.

© 2012, Reggie Johal. All rights reserved.