Dietary protein intake and incidence of type 2 diabetes in Europe: the EPIC-InterAct Case-Cohort Study.
van Nielen M., Feskens EJM., Mensink M., Sluijs I., Molina E., Amiano P., Ardanaz E., Balkau B., Beulens JWJ., Boeing H., Clavel-Chapelon F., Fagherazzi G., Franks PW., Halkjaer J., Huerta JM., Katzke V., Key TJ., Khaw KT., Krogh V., Kühn T., Menéndez VVM., Nilsson P., Overvad K., Palli D., Panico S., Rolandsson O., Romieu I., Sacerdote C., Sánchez M-J., Schulze MB., Spijkerman AMW., Tjonneland A., Tumino R., van der A DL., Würtz AML., Zamora-Ros R., Langenberg C., Sharp SJ., Forouhi NG., Riboli E., Wareham NJ., InterAct Consortium None.
OBJECTIVE: The long-term association between dietary protein and type 2 diabetes incidence is uncertain. We aimed to investigate the association between total, animal, and plant protein intake and the incidence of type 2 diabetes. RESEARCH DESIGN AND METHODS: The prospective European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study consists of 12,403 incident type 2 diabetes cases and a stratified subcohort of 16,154 individuals from eight European countries, with an average follow-up time of 12.0 years. Pooled country-specific hazard ratios (HRs) and 95% CI of prentice-weighted Cox regression analyses were used to estimate type 2 diabetes incidence according to protein intake. RESULTS: After adjustment for important diabetes risk factors and dietary factors, the incidence of type 2 diabetes was higher in those with high intake of total protein (per 10 g: HR 1.06 [95% CI 1.02-1.09], P(trend) < 0.001) and animal protein (per 10 g: 1.05 [1.02-1.08], P(trend) = 0.001). Effect modification by sex (P < 0.001) and BMI among women (P < 0.001) was observed. Compared with the overall analyses, associations were stronger in women, more specifically obese women with a BMI >30 kg/m(2) (per 10 g animal protein: 1.19 [1.09-1.32]), and nonsignificant in men. Plant protein intake was not associated with type 2 diabetes (per 10 g: 1.04 [0.93-1.16], P(trend) = 0.098). CONCLUSIONS: High total and animal protein intake was associated with a modest elevated risk of type 2 diabetes in a large cohort of European adults. In view of the rapidly increasing prevalence of type 2 diabetes, limiting iso-energetic diets high in dietary proteins, particularly from animal sources, should be considered.