Dietary intake of total, animal, and plant proteins and risk of frailty: A GRADE-assessed systematic review and dose-response meta-analysis of prospective cohort studies
Abstract
BACKGROUND & AIMS
There is a knowledge gap about the dose-response association between types of protein intake and frailty risk. We designed a systematic review and dose-response meta-analysis of prospective cohort studies to synthesize the current evidence on the relationship between total, animal, and plant protein consumption and the risk of frailty.
METHODS
We conducted a systematic literature search across online databases, including PubMed, Scopus, Web of Science, and Google Scholar to identify relevant publications up to August 1, 2025. We calculated the pooled relative risk (RR) and 95 % confidence intervals (95 % CI) for the highest and lowest protein intake categories, using a random-effects model to account for variation across studies. To shed light on the shape of the association between total, animal, and plant protein intake and frailty, both linear and non-linear dose-response analyses were performed.
RESULTS
A total of seven prospective cohort studies were included in the analysis. Among the 125,322 individuals, 18,486 cases were reported during the 3 to 22-year follow-up. Higher total protein consumption was associated with a lower risk of frailty than the lowest intake (RR: 0.79; 95 % CI: 0.62, 1.00; I2 = 82.7 %; n = 7; GRADE = very low). Plant protein intake was found to reduce the risk of frailty significantly (RR: 0.87; 95 % CI: 0.82, 0.93; I2 = 3.2 %; n = 4; GRADE = moderate). We did not observe any linear or non-linear association between total,…
How strong is the evidence?
Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 125,322 participants or records.
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