Omega 3s and Protein Synthesis: Will Fish Oils Increase Muscle?

Key Findings on Omega-3s and Protein Synthesis:

This study set out to determine the relationship between omega-3s and protein synthesis. Some studies have found beneficial effects of omega 3’s and protein synthesis, whereas others have not.
Omega-3 supplementation did not have a beneficial effect on muscle protein synthesis rates in young, healthy adults or clinical populations.
Individuals with chronic inflammation or chronic disease such as muscle wasting might experience greater benefits from omega-3 supplementation.

Omega-3s and Protein Synthesis: A New Perspective on Muscle Growth

For years, omega-3 fatty acids have been renowned for their many benefits, including heart health, inflammation reduction, and cognitive function. Fitness enthusiasts and bodybuilders have long advocated consuming fish oils to protein shakes, believing they could enhance muscle gains. A 2015 study found that consuming omega-3 fatty acids with resistance training could maximize their anabolic effects, particularly when combined with protein intake.¹ However, the scientific evidence has been mixed, with some studies showing benefits and others finding no significant effects.^1-5

A recent systematic review and meta-analysis by Atiporn Therdyothin and colleagues titled “The Effects of Omega-3 Polyunsaturated Fatty Acids on Muscle and Whole-Body Protein Synthesis“, published in Nutrition Reviews in May 2024, adds new insights to omega3s and protein synthesis.⁶ This study sought to settle some controversies surrounding omega-3s and muscle protein synthesis (MPS) in healthy adults and clinical populations, providing fitness enthusiasts and researchers with up-to-date conclusions on whether supplementing omega-3 fatty acids aids muscle protein synthesis.

Understanding Protein Synthesis: Whole-Body vs. Muscle-Specific

Before diving into the results of the study, it’s crucial to understand the difference between whole-body protein synthesis and muscle protein synthesis:

Whole-Body Protein Synthesis: This measure reflects the total rate of protein production throughout the entire body, including all organs and tissues. It provides a broader picture of overall protein metabolism and can be influenced by factors affecting various body systems.

Muscle Protein Synthesis (MPS) refers explicitly to the protein synthesis rate within skeletal muscle tissue. MPS is a key factor in muscle growth and repair and is often the primary focus in exercise and muscle hypertrophy studies.

When looking at studies on muscle growth, one should be more concerned with muscle protein synthesis than whole-body protein synthesis.

Review of the Literature on Omega-3 Fatty Acids and Protein Synthesis

Over the past decade, studies have explored the potential of omega-3s to increase muscle mass and improve protein synthesis. Early research found that omega-3 supplementation enhanced muscle protein synthesis in response to anabolic stimuli in younger and older adults.⁷ However, some studies have found no statistical effect of omega-3 fatty acid ingestion on MPS rates in young, healthy men under resting and postexercise conditions.⁸ Another study indicated that omega-3s could improve muscle mass in women but not in older men during resistance exercise.⁹ Similarly, combining leucine-enriched protein with n-3 PUFA did not result in any additional response of MPS compared with protein supplementation alone in older adults.¹⁰ As such, the research on omega-3s and muscle growth remains controversial, warranting further investigation.

Study Protocol for Omega-3 Fatty Acids and Protein Synthesis Research

Therdyothin et al.’s systematic review analyzed eight randomized controlled trials to examine the effects of omega-3 polyunsaturated fatty acids (PUFAs) on muscle and whole-body protein synthesis. These studies included healthy adults and clinical populations, such as patients with chronic diseases like COPD or end-stage renal disease.

Participants in these studies consumed various doses of omega-3 PUFAs, ranging from 2 to 4 grams per day, for durations between 4 weeks and 6 months. Most studies used double-blind RCTs, where neither participants nor researchers knew whether omega-3s or placebo was being administered. The trials also involved resistance exercises or immobilization phases to assess how omega-3 supplementation influenced muscle recovery and growth under physical stress.

The studies compared muscle protein synthesis (MPS) between omega-3 and placebo groups. MPS was measured using fractional synthetic rate (FSR), which represents the rate at which muscle proteins are synthesized in response to feeding, exercise, or other anabolic stimuli. Whole-body protein synthesis was also measured in several trials, providing a broader look at how omega-3s affect overall protein turnover in the body.

Results of the Study on Omega-3 Fatty Acids and Protein Synthesis

The study found no significant effect of omega-3 supplementation on muscle protein synthesis across the eight RCTs analyzed. This finding was consistent regardless of the participant’s age, health condition, or the dose and duration of omega-3 supplementation. In some cases, omega-3s appeared to improve muscle function or mass, but these effects were not directly linked to increased MPS.

However, there was a significant improvement in whole-body protein synthesis in three studies included in the review. This effect was particularly strong in clinical populations, such as those with chronic inflammation or cachexia (muscle-wasting conditions), suggesting that omega-3s may help enhance overall protein turnover in individuals with health challenges.

Interestingly, the studies found that while omega-3s do not boost MPS directly, they might reduce muscle protein breakdown (MPB). This reduction in MPB could contribute to the preservation of muscle mass, even in the absence of increased synthesis. In contrast, n-3 PUFA supplementation significantly increased whole-body protein synthesis rates. The beneficial effect was particularly noted in clinical populations, such as patients with chronic inflammation and muscle wasting disease.

Discussion: Omega-3 Fatty Acids and Protein Synthesis in Practice

So, what does this all mean for those looking to build muscle through omega-3 supplementation? The key takeaway is that omega-3 fatty acids may not directly enhance muscle protein synthesis in healthy individuals but can still offer muscle health benefits. The most compelling evidence points to omega-3s’ ability to improve whole-body protein synthesis and reduce muscle protein breakdown, particularly in populations with chronic diseases. In addition, there is evidence that omega-3s help combat inflammation, a key factor in muscle degradation. By reducing inflammation, omega-3s may indirectly protect against muscle loss and improve recovery from exercise or injury.

Recommendations:

Focus on food sources: Fatty fish like salmon, mackerel, and sardines are excellent natural sources of omega-3s. Aim to include these in your diet 2-3 times per week.
The benefits of omega-3s may be more pronounced in certain populations, such as older adults or those with chronic inflammatory conditions.
Remember that omega 3s are just one piece of the muscle-building puzzle. Prioritize consistent resistance training, adequate protein intake, and sufficient rest for optimal results.

References

1 Jeromson, S., Gallagher, I. J., Galloway, S. D. R. & Hamilton, D. L. Omega-3 Fatty Acids and Skeletal Muscle Health. Marine Drugs 13, 6977-7004 (2015). https://doi.org/10.3390/md13116977

2 Moon, G. K. & Bu, S. Y. Effects of Omega-3 Fatty Acid Supplementation on Skeletal Muscle Mass and Strength in Adults: A Systematic Review. Clinical Nutrition Research 12, 304 (2023). https://doi.org/10.7762/cnr.2023.12.4.304

3 Huang, Y. L., Chiu, W. C., Hsu, Y. P., Lo, Y. L. & Wang, Y. H. Effects of Omega-3 Fatty Acids on Muscle Mass, Muscle Strength and Muscle Performance Among the Elderly: A Meta-Analysis. Nutrients 12, 3739 (2020). https://doi.org/10.3390/nu12123739

4 Herbst, E. A. F. et al. Omega‐3 Supplementation Alters Mitochondrial Membrane Composition and Respiration Kinetics in Human Skeletal Muscle. The Journal of Physiology 592, 1341-1352 (2014). https://doi.org/10.1113/jphysiol.2013.267336

5 McGlory, C. et al. Omega-3 fatty acid supplementation attenuates skeletal muscle disuse atrophy during two weeks of unilateral leg immobilization in healthy young women. Faseb j 33, 4586-4597 (2019). https://doi.org/10.1096/fj.201801857RRR

6 Therdyothin, A., Prokopidis, K., Galli, F., Witard, O. & Isanejad, M. The effects of omega-3 polyunsaturated fatty acids on muscle and whole-body protein synthesis: a systematic review and meta-analysis. Nutrition reviews (2024). https://doi.org/10.1093/nutrit/nuae055

References

7 Smith, G. I. 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, 402-412 (2011). https://doi.org/10.3945/ajcn.110.005611

8 McGlory, C. et al. Fish oil supplementation suppresses resistance exercise and feeding-induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men. Physiol Rep 4 (2016). https://doi.org/10.14814/phy2.12715

9 Da Boit, M. 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). https://doi.org/10.3945/ajcn.116.140780

10 Deger, S. M. et al. High Dose Omega-3 Fatty Acid Administration and Skeletal Muscle Protein Turnover in Maintenance Hemodialysis Patients. Clin J Am Soc Nephrol 11, 1227-1235 (2016). https://doi.org/10.2215/cjn.04150415