Impact of protein and exercise on Muscle Protection, Health, and Aging
This post summarises key insights regarding protein intake, distribution, and quality, drawing from the summary of a Dr. Rhonda Patrick research. It addresses the significance of protein in combating age-related muscle loss, optimising muscle protein synthesis, and promoting overall health.
Key Themes & Ideas:
Age-Related Muscle Decline (Sarcopenia):
Muscle mass and strength diminish with age. After age 50, the average person loses approximately 1% of muscle mass and 3% of strength annually. This accelerates further (4% strength loss) by age 75 if resistance training isn't incorporated.
This loss contributes significantly to frailty and increases the risk of falls and fractures, including potentially fatal hip fractures. "Research shows that individuals who experience fragility fractures have double the mortality risk, with 22–58% of those with hip fractures dying within 12 months.”
Optimal Protein Intake:
The Recommended Dietary Allowance (RDA) of 0.8 grams per kilogram of body weight is inadequate for optimal health, according to the research cited.
Stable isotope studies suggest an optimal daily protein intake of 1.2 to 1.6 grams per kilogram of body weight (0.54 to 0.72 grams per pound).
A minimum of 1.2g/kg per day can reduce frailty by 30% in older adults. "For those engaged in resistance training, 1.6g/kg per day has been shown to maximize gains in lean mass, with a 27% increase compared to a 1.2g/kg intake."
Protein needs should be based on lean body mass or an adjusted goal weight that reflects a healthy body fat percentage (12-15% for men and 20% for women).
The amount may increase for athletes, older adults, and those aiming for fat loss while preserving muscle.
Protein Timing and Distribution:
The body can effectively use large protein doses, dispelling the myth of a 20-25g limit per meal. "Studies by Dr. Luc van Loon and colleagues found that consuming 100 grams of protein after exercise elicited a robust and prolonged anabolic response…”
Evenly distributing protein intake across 3–4 meals is ideal to maximise muscle protein synthesis.
Focusing on the total daily intake is more critical than precise meal timing, though spreading it out is generally preferable.
Protein Quality and Leucine:
High-quality proteins are more readily digested and utilised for muscle protein synthesis.
Leucine is a crucial branched-chain amino acid that activates the mTOR pathway, driving muscle protein synthesis. “A key determinant is the presence of leucine, a branched-chain amino acid that acts as the primary driver of muscle protein synthesis by activating the mTOR pathway.”
Leucine thresholds of 2-3 grams per meal must be met for effective muscle protein synthesis. "This can be obtained by consuming 20 grams of a high-quality protein such as whey protein."
Aging increases the leucine threshold, but regular exercise can improve muscle sensitivity to leucine.
The Role of IGF and mTOR in Longevity:
Some studies suggest that high protein diets, especially from animal sources, may increase the risk of cancer and accelerate aging by increasing levels of IGF-1 and activating mTOR.
However, "these risks often disappear when accounting for other lifestyle factors such as obesity, smoking, heavy drinking, or sedentary behavior.” High-protein diets don’t show the same negative associations among healthy individuals.
Exercise plays a crucial role in directing growth factors such as IGF-1 and mTOR to beneficial functions like muscle and brain health.
Practical Recommendations (Key Takeaways):
Optimal Protein Intake: Aim for 1.2-1.6 grams of protein per kilogram of body weight daily. Older adults, athletes and those wanting to lose fat and preserve lean mass may need more than 1.6g/kg. Calculate protein needs based on lean mass.
Anabolic Window: The anabolic window post-exercise is more flexible than once thought. Focus on total daily protein intake.
Protein Distribution: Spread protein intake across 3–4 meals, with each meal containing 20-25 grams of high-quality protein. Older adults should aim for 20-30g per meal.
Pre-sleep Protein: Consider consuming protein before bed to enhance overnight muscle protein synthesis.
Protein Supplementation: High-quality supplements like whey and casein offer benefits for recovery and performance, although are not essential if protein needs are met through diet alone.
Animal vs. Plant Protein: Animal proteins are generally superior due to their bioavailability and complete amino acid profiles (especially leucine). Plant-based eaters can meet needs by consuming larger quantities, diversifying protein sources and using protein isolates and concentrates.
Kidney Health: High protein intake is safe for those without pre-existing kidney problems.
Protein, Cancer, and Longevity: Human evidence does not strongly support the notion that high protein intake reduces longevity or promotes cancer risk in otherwise healthy individuals.
Conclusion:
Follow these recommendations to protect your muscles and stay healthy. Try our app BreathNow for specific exercises which help to protect muscles, slow aging and positively impact blood pressure.