Omega-3 & Muscle Protein Synthesis

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Interpreting what the research says in regards to the effects of omega-3 polyunsaturated fatty acid consumption is notoriously difficult. There are a wide range of findings on the topic, which in nutritional research is often in part be due to differences in study designs and the challenge of controlling for variables such as existing background levels in the diet of a particular nutrient. The impact of omega-3 consumption appears to be particularly tricky to pin down as effects seem to be heavily dose and form dependent. That being said, there are some reasonable conclusions we can draw from the research that has been done on this topic when we look at the response of specific populations...

A recent (2024) systematic review (summary of multiple research studies) found that omega-3 consumption is associated with whole body protein synthesis rather than specifically muscle protein synthesis, and may be most impactful in healthy adults for improving neuromuscular function (Therdyothin et. al., 2024). The authors of this analysis concluded that omega-3 consumption was most beneficial for whole body protein synthesis in those with chronic inflammation and other comorbidities (Therdyothin et. al., 2024). 

So does this mean that omega-3 intake is not important for skeletal muscle? Not exactly. Remember that when looking the findings of multiple research studies, conflicting results (such as an increase in whole body protein synthesis but no significant increase in muscle protein synthesis) are likely due to variations in study design, such as the target population, form and dose. If we look at the research done in specific populations, one population whose skeletal muscle appears to more clearly benefit of omega-3 consumption is older adults. 

First off, let's look at why lean muscle mass is so important as we age. As we get older, we tend to naturally lose lean muscle mass, strength, and quality (sarcopenia), and that can leave our bodies more vulnerable in times of stress, injury or illness as the body needs a reserve of muscle to break down into amino acids with which to build in to new tissues and promote healing. Essentially, our skeletal muscle acts as a bit of a 'health insurance' as we age. When we have more materials on hand to patch our shelter, we can better weather the storms so to speak. 

Omega-3s (in supplement or dietary form) appear to have antisarcopenic effects in older adults, by way of promoting muscle protein syntheses in this population (Grays & Mittendorfer, 2018). This seems to be particularly notable in those who have a less active lifestyle (Grays & Mittendorfer, 2018). In older adults, high levels of omega-3 consumption appear to be associated with a reduction in the emission of harmful reactive oxygen species during cellular respiration (this is a good thing - it means less oxidative stress), an increase in muscle protein synthesis after consuming protein, and a stronger anabolic (muscle building) response after exercise (Lalia et. al., 2017). Interestingly, the effect of omega-3 intake on muscle mass in older adults appears to be more significant in populations experiencing prolonged inflammation or chronic wasting conditions (Therdyothin et. al., 2023).  

So how much omega-3 intake is associated with muscle protein synthesis benefits in older adults? A relatively recent systematic review (2020) looking specifically at studies targeting this population, found that a beneficial effect of omega-3 consumption on skeletal muscle mass was largely seen when the older adults were consuming more than 2g/day (Huang et. al., 2020). While it is always best (and safest) to get your nutrients from whole foods, for some people it may be preferable to supplement their omega-3 both to achieve a clinically relevant dose and to minimize heavy metal exposure from seafood. 

To summarize, research indicates that high dose (>2g/day) omega-3 consumption may be beneficial for muscle mass in older adults, particularly in those with chronic inflammation and other comorbidities. 

This article is intended for educational and informational purposes only. Always talk with your doctor or a qualified health care professional before changing your omega-3 consumption or if you are considering supplementation.