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#081 Chris McGlory, PhD, on the Anabolic Potential of Omega-3 Fatty Acids

Mon Jul 03 2023
Omega-3Muscle HealthProtein SynthesisMuscle DeclineResistance Training


Omega-3 fatty acids play a crucial role in muscle health, preventing disused atrophy and enhancing muscle protein synthesis. Dr. Chris McGlory's research focuses on determining the optimal dose and duration of omega-3 supplementation for muscle health. Immobilization and reduced physical activity can lead to rapid declines in muscle mass, especially in older adults. Omega-3s may mitigate muscle decline, enhance protein synthesis, and improve strength response to resistance training. Future research aims to explore the effects of omega-3s on different populations and understand their mechanisms of action.


Omega-3s Enhance Muscle Protein Synthesis

Omega-3 fatty acids have been shown to enhance muscle protein synthesis, making them beneficial for maintaining muscle mass and preventing disuse atrophy.

Omega-3s Improve Strength Response to Resistance Training

Omega-3 supplementation enhances the strength response to resistance training, especially in women. This suggests that omega-3s can contribute to gains in strength.

Omega-3s Mitigate Muscle Decline

Omega-3s may mitigate muscle decline in various populations, including older adults and cancer patients undergoing chemotherapy.

Optimal Dose and Duration of Omega-3 Supplementation

Determining the optimal dose and duration of omega-3 supplementation is crucial for accurately observing its effects on muscle health.

Combining Aerobic and Resistance Training

Combining aerobic exercise with resistance training has overall benefits for muscle health, as it promotes muscle growth and cardiovascular function.

Measuring Hypertrophy and Conclusion

Measuring hypertrophy requires more than just assessing cross-sectional area of individual fibers. Further high-quality studies are needed to fully understand the effects of omega-3s on muscle health.


  1. Omega-3 and Muscle Health
  2. Research Background and Collaborations
  3. Muscle Protein Synthesis and Disuse Atrophy
  4. Impact of Omega-3 on Muscle Health
  5. Study on Omega-3 and Muscle Decline
  6. Challenges and Future Research
  7. Optimal Dose and Duration of Omega-3 Supplementation
  8. Omega-3 and Muscle Strength
  9. Omega-3 and Glucose Handling
  10. Omega-3 and Muscle Protein Synthesis
  11. Omega-3 and Glucose Handling in Muscle
  12. Omega-3 and Glucose Transporters
  13. Challenges and Future Research
  14. Combining Aerobic and Resistance Training
  15. Measuring Hypertrophy and Conclusion

Omega-3 and Muscle Health

00:00 - 07:20

  • Omega-3 fatty acids have a role in muscle health and can help prevent disused atrophy.
  • Even a short period of immobilization can result in significant muscle loss.
  • Omega-3 fatty acids may enhance muscle protein synthesis, especially in response to protein consumption.
  • This effect is particularly relevant for older adults who often have insufficient protein intake and reduced ability to respond to it.
  • Dr. Chris McGlory's research aims to determine the optimal dose and duration of omega-3 supplementation for muscle health.
  • Omega-3 may improve muscle strength and walking performance, especially when combined with resistance training.
  • The potential anabolic effects of omega-3 on muscle growth are still being investigated.
  • In Dr. McGlory's study, participants received 5 grams of omega-3 per day, which is higher than typical doses used for other purposes.
  • A high percentage of people would benefit from higher omega-3 intake.

Research Background and Collaborations

07:04 - 13:46

  • Researcher started their career in Liverpool, focusing on muscle protein metabolism and nutritional interventions
  • Collaborated with experts in stable isotope traces to study the effects of protein ingestion on skeletal muscle
  • Opportunity arose to study the effects of different lipids, specifically omega-3, on skeletal muscle
  • Conducted studies on time course change in muscle lipid profiles and muscle protein synthesis with omega-3 intake and exercise
  • Moved to Canada and focused on omega-3's influence in clinical settings such as muscle loss and aging
  • Collaborated with experts in mitochondrial biology to explore the role of omega-3s in muscle response
  • Published papers on omega-3 feeding with immobilization in young women and its impact on mitochondria
  • Landed a job at Queens University and established a lab to further research omega-3s and human skeletal muscle

Muscle Protein Synthesis and Disuse Atrophy

13:16 - 20:21

  • Reduction in muscle protein synthesis leads to a negative balance of skeletal muscle over time, resulting in loss of muscle size and strength.
  • Younger individuals can recover from muscle loss more quickly with rehabilitation and exercise, but older adults may struggle to regain lost muscle mass after surgery or injury.
  • The Catabolic Crisis Model suggests that repeated periods of inactivity and immobilization can lead to a progressive loss of muscle mass beyond which daily activities become difficult.
  • Increasing protein intake, particularly essential amino acids like leucine, can partially protect against muscle decline but cannot completely prevent it.
  • Prolonged immobilization, such as during surgery or bed rest, leads to rapid declines in muscle mass within the first seven days.
  • Reduced physical activity, such as during the pandemic or due to decreased step count, also results in downregulation of protein synthesis and incomplete recovery even after two weeks.

Impact of Omega-3 on Muscle Health

20:04 - 26:57

  • In older pre-diabetic populations, there was a down regulation of protein synthesis that wasn't fully recovered after two weeks of reduced activity.
  • Indices of insulin sensitivity and resistance were compromised and didn't recover.
  • Reduced step count during quarantine may have negative metabolic effects and down regulation of protein synthesis.
  • Winter weather can lead to reduced step count and contribute to muscle disuse atrophy.
  • Muscle disuse atrophy can occur without severe immobilization, such as during winter or periods of reduced activity.
  • The disability threshold is the point where assistance is required for mobility, which can be accelerated by repeated insults of inactivity.
  • It's difficult to quantify the number of periods required to reach the disability threshold, but staying physically active throughout life is important.
  • Additional nutritional interventions, like omega-3 supplementation, may help mitigate disuse atrophy.
  • Omega-3 fatty acids can enhance muscle sensitivity to amino acids and potentially restore muscle function during periods of disuse.

Study on Omega-3 and Muscle Decline

26:43 - 33:21

  • The study involved immobilizing one leg of participants and measuring muscle size, protein synthesis, gene expression, and mitochondrial analysis.
  • Omega-3s were found to be protective against muscle decline and helped with faster recovery.
  • The omega-3 group showed higher rates of protein synthesis, suggesting that omega-3s enhance the protein synthetic response to daily protein intake.
  • Omega-3s may lessen the decrease in muscle protein synthesis during disuse and could potentially enhance the effect of lower amounts of protein intake.
  • In situations where large amounts of protein cannot be consumed, such as in hospitals or for elderly individuals, omega-3s may potentiate the normal response to low-dose protein intake.
  • No studies have specifically addressed the combination of essential amino acids or protein with omega-3s for a more robust effect on muscle protein synthesis.
  • A secondary analysis found a trend for increased gene expression of an amino acid transporter associated with enhanced protein synthesis in the omega-3 group.

Challenges and Future Research

33:09 - 40:18

  • I'm less convinced of the trend of a treatment effect over time.
  • The accumulation of omega-3 fatty acids in cell membranes changes transporter receptors' structure and function.
  • DHA deficiency in rodents significantly alters gluten-one transporters responsible for transporting glucose across the blood-brain barrier.
  • The antibody for human skeletal muscle protein was difficult to work with at the time, but it has improved recently.
  • No studies have looked at the effect of Omega 3s on disuse atrophy in older adults or males.
  • Omega-3s were chosen for study in women due to their susceptibility to ACL injuries and evidence suggesting they are more effective than in men.
  • The jury is still out on whether omega-3s enhance the response to amino acids and skeletal muscle anabolic resistance in older adults.
  • The effectiveness of feeding omega-3s may depend on individuals' omega-3 status and protein intake levels.
  • More studies are needed to understand omega-3's role in disuse atrophy across different populations and genders.

Optimal Dose and Duration of Omega-3 Supplementation

46:26 - 53:20

  • The cost of conducting high-quality studies in specific populations is a major challenge due to the need for funding.
  • To produce strong, well-designed randomized controlled trials (RCTs) and high-quality meta-analyses, there is a need for higher quality evidence.
  • Changes in skeletal muscle lipid profile due to omega-3 intake take around four weeks to become significant.
  • The mechanism of action of omega-3 involves modifying the composition of target tissues, particularly the phospholipid membrane of muscle cells.
  • Designing clinical trials with an understanding of the time it takes for omega-3 fatty acids to be incorporated into cell membranes is crucial for accurate results.
  • A loading phase of four weeks before mobilization can ensure substantial changes in muscle lipid profile are observed.
  • It would be interesting to explore acute effects by giving an immediate dose of omega-3 supplements, but it is unlikely to have a significant impact on the proposed mechanism of action.
  • Further research is needed to determine how low the change in muscle composition can be while still observing effects and whether shorter feeding or loading periods are feasible.

Omega-3 and Muscle Strength

52:56 - 59:29

  • Impact of omega-3 on resolving inflammation and its role in muscle mass
  • Omega-3 metabolites like SPMs can resolve inflammation quickly
  • Anti-inflammatory role of omega-3 in muscle mass and inflammatory conditions
  • Differences between gaining muscle mass and strength in older people
  • Anabolic resistance to protein or amino acid ingestion in older individuals
  • Older people can still gain strength through resistance exercise
  • Lack of exercise engagement may explain the difficulty in gaining muscle mass for older individuals
  • The role of nutrition, specifically amino acids, in gains and strength
  • Increased muscle mass may contribute to gains in strength through amino acid ingestion
  • Omega-3 supplementation enhances strength response to resistance training, especially in women
  • Possibility of DHA incorporation into neural networks enhancing strength adaptation with omega-3 intake
  • Sex differences observed in the effects of omega-3 on strength gains, more pronounced in women
  • Preliminary evidence suggests that omega-3 supplementation alone or with resistance training confers strength benefits, particularly in women
  • Estrogen plays a role in converting plant-based ALA into EPA and DHA

Omega-3 and Glucose Handling

1:06:07 - 1:13:10

  • Estrogen plays a role in converting plant omega-3 into EPA and DHA.
  • Women can convert omega-3 more efficiently than men.
  • There may be minimal differences in muscle gains between younger men and women.
  • Resistance exercise may explain some sex differences in older folks.
  • Omega-3 supplementation may improve walking speed or performance in older people.
  • More well-designed trials are needed to confirm the effects of omega-3.
  • Omega-3s may play a role in maintaining muscle mass and preventing disuse atrophy.
  • Increasing omega-3 content through diet or supplements is generally safe and beneficial, especially for recovery from surgery.
  • Sarcopenia, the loss of muscle mass with age, is associated with various health problems.
  • Omega-3 fatty acids can help shift the balance towards muscle anabolism in sarcopenia.

Omega-3 and Muscle Protein Synthesis

59:05 - 1:06:29

  • Older adults experience anabolic resistance to protein ingestion, leading to negative protein balance and muscle decline.
  • Exercise, especially resistance exercise, is crucial for enhancing or maintaining muscle mass and strength.
  • Omega-3 supplements have been shown to enhance protein synthesis in both younger and older individuals.
  • Longitudinal studies have demonstrated significant changes in muscle mass with omega-3 supplementation.
  • Omega-3s may have an anti-inflammatory effect on sarcopenia, potentially resolving inflammation inside the muscle.
  • Intracellular amino acid concentrations can be measured, but there is limited evidence of their increase in muscle issues.
  • Omega-3s may not work via transport mechanisms but rather improve intracellular mechanisms related to protein synthesis.
  • There is mixed literature on the effects of omega-3s on glucose transport into muscles.

Omega-3 and Glucose Handling in Muscle

1:06:07 - 1:13:10

  • Glucose transport in muscle is not necessarily anabolic, and the literature on its effects is mixed.
  • The effects of omega-3s on glucose handling in humans with type 2 diabetes are inconclusive.
  • Omega-3s may modulate mitochondria in human skeletal muscle, affecting ADP sensitivity and respiration.
  • There is evidence of cross talk between mitochondrial protein synthesis and factors that regulate protein synthesis in skeletal muscle.
  • Limited evidence suggests that DHA and EPA can increase metabolic rate and fat oxidation, potentially through mitochondrial mechanisms.
  • High doses of omega-3s may shift substrate oxidation towards fatty acids, which could have implications for glucose homeostasis.

Omega-3 and Glucose Transporters

1:19:26 - 1:26:24

  • Omega-3s may increase glucose transporters in skeletal muscle, potentially benefiting diabetic patients or those with high levels of circulating glucose.
  • There is no evidence of increased group four transporters in skeletal muscle with omega-3s.
  • The protein content in skeletal muscle may not always be functional or efficient.
  • The accumulation of omega-3s in mitochondrial membranes may take a similar amount of time as in skeletal muscle lipid membranes (around four weeks).
  • Eating fatty fish like salmon and mackerel is the best source of omega-3, but it may not provide the recommended daily dose of four to five grams.
  • The level of omega-3s or EPA and DHA in muscle membranes that is linked to clinical outcomes is still unknown.
  • Determining the optimal dose and duration for omega-3 supplementation requires further research.
  • The effect of omega-3 on anabolic signaling pathways like M-tor and P70S6K1 is complex and not fully understood.
  • It is unclear whether the effects on anabolic pathways are direct or indirect through amino acid potentiation.
  • Inflammation can inhibit protein synthesis in skeletal muscle, but measuring breakdown is challenging.

Challenges and Future Research

1:26:09 - 1:32:57

  • Inflammation in the muscle can impede protein synthesis and affect initiation factors.
  • Omega-3s may mitigate muscle decline in cancer patients and protect against chemotherapy-induced atrophy.
  • Ongoing trials are investigating the effects of omega-3s on muscle mass and strength in various populations.
  • Future studies aim to explore the effects of omega-3s on older individuals and ICU patients.
  • The focus is on clinical outcomes and understanding the mechanisms behind omega-3s' effects on muscle.
  • The speaker has shifted their training routine to incorporate more resistance training.

Combining Aerobic and Resistance Training

1:32:36 - 1:36:13

  • Aerobic exercise may actually promote muscle growth by enhancing capillaryization and nutrient delivery to the muscles.
  • Endurance exercise can activate satellite cells, which contribute to muscle remodeling and growth in response to resistance training.
  • There is evidence that combining aerobic exercise with resistance training does not have an interfering effect on muscle hypertrophy.
  • VO2 max and exercise capacity are important for cardiovascular health and function, so incorporating both endurance and resistance training is beneficial.
  • Doing aerobic exercise after resistance training could also be effective in promoting capillary dilation and nutrient delivery to the muscles.
  • The potential interference effect between aerobic and resistance training is outweighed by the overall benefits of engaging in both types of exercise.
  • The measurement of hypertrophy should go beyond just cross-sectional area of individual fibers, using methods like MRI for more accurate assessment.

Measuring Hypertrophy and Conclusion

1:36:13 - 1:42:00

  • Cross-sectional area of individual fibers alone may not be sufficient to assess hypertrophy.
  • MRI data and measures of hypertrophy can provide more insight.
  • Conflicting data on types of procedures used can affect clarity.
  • Omega-3 may have anabolic effects and be relevant for muscle disuse atrophy and sarcopenia.
  • Low amino acid intake and optimizing sensitizing amino acids are also important.
  • More high-quality studies needed in the future.
  • Dr. Chris McGlory's research can be found on ResearchGate or by email.
  • Opportunity to talk about Omega-3 is rare and appreciated.