July 3, 2023 • 1hr 36min

#081 The Anabolic Potential of Omega-3 Fatty Acids | Chris McGlory, PhD

FoundMyFitness

Dr. Chris McGlory is an assistant professor at Queen's University in Kingston, Ontario, Canada. His research focuses on the effects of omega-3 fatty acids on muscle metabolism, particularly in the context of muscle loss during disuse and aging. In this episode, Dr. McGlory discusses his work investigating how omega-3 supplementation may help prevent muscle atrophy and enhance muscle protein synthesis.

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Key Takeaways

Omega-3 fatty acids may help prevent muscle loss during periods of disuse or immobilization. A study in young women found omega-3 supplementation was protective against muscle loss during leg immobilization.
Omega-3s may enhance muscle protein synthesis in response to protein intake, particularly in older adults who experience "anabolic resistance" to protein.
It takes about 4-6 weeks of omega-3 supplementation to significantly increase omega-3 levels in muscle cell membranes. This "preloading" period is important for study design.
Omega-3s may improve muscle strength and physical performance in older adults, especially when combined with resistance training.
The mechanisms are still unclear but may involve changes to cell membrane composition, mitochondrial function, and anabolic signaling pathways.
More high-quality randomized controlled trials are needed, especially in older adults and clinical populations, to confirm benefits and determine optimal dosing.
Omega-3s may help protect against muscle wasting in cancer cachexia and mitigate negative effects of chemotherapy on muscle, though evidence is still preliminary.
Combining aerobic and resistance exercise may have synergistic effects on muscle growth, contrary to concerns about interference effects.

Introduction

Dr. Chris McGlory is an assistant professor at Queen's University in Kingston, Ontario, Canada. His research focuses on the effects of omega-3 fatty acids on muscle metabolism, particularly in the context of muscle loss during disuse and aging. In this episode, Dr. McGlory discusses his work investigating how omega-3 supplementation may help prevent muscle atrophy and enhance muscle protein synthesis.

Topics Discussed

Muscle Disuse Atrophy (13:16)

Dr. McGlory explains that muscle disuse atrophy occurs when there is a reduction in muscle protein synthesis due to inactivity or immobilization. This can happen rapidly, with significant muscle loss occurring within 7-14 days of disuse.

Disuse atrophy is more problematic for older adults, as they may not fully recover lost muscle mass
Repeated bouts of disuse can lead to a "catabolic crisis" and crossing a "disability threshold"
Even reduced physical activity (e.g. low step count) can cause some degree of muscle loss

Omega-3 Effects on Muscle Disuse Atrophy (24:58)

Dr. McGlory describes a study his team conducted examining the effects of high-dose omega-3 supplementation on muscle disuse atrophy in young women:

Participants took 5g/day of omega-3s (3g EPA, 2g DHA) for 4 weeks before leg immobilization
Omega-3 group maintained muscle mass better during immobilization
Omega-3 group recovered muscle mass faster after immobilization ended
Effects likely due to enhanced muscle protein synthesis

"It seemed that the omega-3s were completely protective, at least from a mass point of view. [They] took the edge off the decline in muscle size as measured by MRI."

Mechanisms of Omega-3 Effects (28:35)

Dr. McGlory discusses potential mechanisms by which omega-3s may enhance muscle protein synthesis:

Incorporation into cell membranes may enhance sensitivity to anabolic stimuli
May improve amino acid transport into muscle cells (though evidence is mixed)
Could enhance mitochondrial function in muscle
May activate anabolic signaling pathways like mTOR (though likely indirectly)

He notes more research is needed to fully elucidate the mechanisms.

Importance of "Preloading" Omega-3s (41:37)

Dr. McGlory emphasizes the importance of "preloading" omega-3s for 4-6 weeks before studying their effects:

Takes ~4 weeks to significantly increase omega-3 levels in muscle cell membranes
Effects likely depend on changing membrane composition, not acute intake
Many studies may be too short to see full effects

"If we are agreeable that it is the modulation of the lipid profile that is driving the effects, well, the modulation of that profile takes weeks at the doses that we typically use."

Omega-3s and Sarcopenia (58:17)

Dr. McGlory discusses the potential for omega-3s to help combat age-related muscle loss (sarcopenia):

May enhance muscle protein synthesis in response to protein intake in older adults
Some evidence omega-3s can increase muscle mass and strength in older adults
Could help overcome "anabolic resistance" to protein and exercise in aging
More research needed, especially in clinical populations

Omega-3s and Mitochondrial Function (1:07:42)

Dr. McGlory describes ongoing research into how omega-3s may affect mitochondrial function in muscle:

Omega-3s accumulate in mitochondrial membranes
May enhance mitochondrial respiration and energy production
Could improve "mitochondrial-cytosolic crosstalk" related to protein synthesis
More studies underway to investigate these effects

Omega-3s and Cancer Cachexia (1:18:52)

Dr. McGlory discusses preliminary evidence that omega-3s may help combat muscle wasting in cancer:

Some studies show EPA may protect against muscle loss in cancer cachexia
Omega-3s may mitigate negative effects of chemotherapy on muscle (animal studies)
More clinical research needed in this area

Ongoing Clinical Trials (1:22:21)

Dr. McGlory describes several ongoing clinical trials his team is conducting:

S*x differences in muscle responses to omega-3s
Effects of omega-3s + amino acids during bed rest
Omega-3 supplementation for patients undergoing ACL surgery

He notes they are taking a "mechanism-based clinical approach" to study both real-world outcomes and underlying biology.

Combining Aerobic and Resistance Exercise (1:27:05)

Dr. McGlory discusses how combining aerobic and resistance exercise may actually enhance muscle growth:

Contrary to concerns about "interference effects"
Aerobic exercise may enhance blood flow and nutrient delivery to muscles
May activate satellite cells to support muscle growth
Combining modalities likely beneficial for overall health

"It seems that the average everyday person, it's not going to do harm at all to do some aerobic exercise with resistance. And if anything...they may even be synergistic."

Conclusion

Dr. McGlory's research highlights the exciting potential for omega-3 fatty acids to help prevent muscle loss and enhance muscle protein synthesis, particularly in the context of disuse and aging. While more research is needed to fully elucidate the mechanisms and determine optimal protocols, omega-3s may prove to be an important nutritional strategy for maintaining muscle health across the lifespan. Future high-quality clinical trials, especially in older adults and clinical populations, will be crucial for translating these findings into practical recommendations.