A Well-Balanced Vegan Diet Does not Compromise Daily Mixed Muscle Protein Synthesis Rates when Compared with an Omnivorous Diet in Active Older Adults: A Randomized Controlled Cross-Over Trial.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 39732437 · doi:10.1016/j.tjnut.2024.12.019
What was done
A randomized controlled cross-over trial evaluated 34 active, community-dwelling older adults (mean age 72 ± 4 years; 18 males, 16 females; 12,460 ± 4,512 steps/day). Participants consumed a 10-day controlled vegan diet (providing varied plant-based protein sources) and an isocaloric, isonitrogenous controlled omnivorous diet (60% animal protein) in randomized sequence. Daily mixed muscle protein synthesis (MPS) rates were determined using deuterated water dosing with blood and muscle sampling. Secondary outcomes included cardiometabolic markers and appetite.
What was found
Integrated daily mixed MPS rates did not significantly differ between the vegan (1.23 ± 0.04%/d) and omnivorous (1.29 ± 0.04%/d) diets (P = 0.2542). Total cholesterol (Δ0.25 ± 0.04, P < 0.0001), LDL cholesterol (Δ0.23 ± 0.03, P < 0.0001), and HDL cholesterol (Δ0.03 ± 0.14, P = 0.0387) were significantly lower after the vegan diet. Fasting triglycerides, glucose, insulin, HOMA-IR, and blood pressure showed no significant differences between diets (P > 0.05).
Why it matters
These findings indicate that a varied, isonitrogenous vegan diet can sustain short-term daily muscle protein synthesis rates as effectively as an omnivorous diet in healthy older adults.
Limits
The intervention lasted only 10 days per phase and measured surrogate protein synthesis rather than long-term muscle mass, strength, or functional outcomes. The cohort was small and unusually physically active, limiting generalizability to sedentary or frail older individuals.
Cited by
- supports A 9- to 10-day clinical study led by Luc van Loon and funded by Beef Checkoff found no significant difference in daily muscle protein synthesis rates between omnivorous and vegan diets at 1.1 to 1.2 g/kg protein intake in active older adults.