Benefits of Creatine Supplementation for Vegetarians Compared to Omnivorous Athletes: A Systematic Review.
Level 1 - systematic review of randomized trials
Systematic review of randomized trials and prospective studies
PubMed 32349356 · doi:10.3390/ijerph17093041
What was done
A systematic review evaluated the effects of creatine supplementation in vegetarians compared to omnivores. The authors searched PubMed and SPORTDiscus for randomized controlled trials (parallel-group and cross-over) and prospective studies. A total of 64 records were screened, and eleven full-text articles covering nine studies were included in the review.
What was found
The abstract reports qualitative directions of effect without numerical values or effect sizes. Creatine supplementation in vegetarians increased total creatine, free creatine, and phosphocreatine concentrations in plasma, red blood cells, and vastus lateralis and gastrocnemius muscles, often reaching levels higher than in omnivores. No changes were observed in brain phosphocreatine. Creatine supplementation also increased lean tissue mass, type II muscle fiber area, insulin-like growth factor-1, muscular strength, muscular endurance, Wingate mean power output, and cognitive performance (memory and intelligence). Findings were mixed regarding whether exercise performance improvements were greater in vegetarians than in omnivores.
Why it matters
Because vegetarians have lower baseline creatine stores due to meat-free diets, supplementation reliably restores tissue levels and supports strength and muscle mass gains. However, evidence is inconclusive on whether vegetarian athletes gain a larger performance edge compared to omnivores.
Limits
The abstract reports no numerical values, sample sizes, effect sizes, or confidence intervals. The authors explicitly noted that the included primary studies had a moderate-to-high risk of bias, and only nine total studies were identified.