2016 年 17 巻 1 号 p. 60-70
Objective: Low-carbohydrate diets have favorable short-term effects on body weight and risk factors for cardiovascular disease. However, they are potentially associated with an increased long-term risk of mortality. Our objective was to elucidate their effects on the incidence of diabetes.
Methods: Several databases (MEDLINE, EMBASE, ISI Web of Science, Cochrane Library, and ClinicalTrials.gov) were searched for relevant articles that were published prior to May 2015. Cohort studies with a follow-up period of at least one year were included. Identified articles were systematically reviewed, and those with pertinent data were selected for inclusion in a meta-analysis. The pooled risk ratio (RR) with 95% confidence interval (CI) for the incidence of diabetes was calculated using the random-effects model with inverse-variance weighting.
Results: We included 13 studies in a systematic review, followed by a meta-analysis using pertinent data. Among the 440,669 people that were included in 11 cohort studies, 27,887 (6.3%) cases of diabetes were documented. The risk of incident diabetes among individuals with a low-carbohydrate diet was not significantly different from that of individuals with a high-carbohydrate diet: the pooled RR was 1.03 (95% CI, 0.91–1.16).
Conclusion: Low-carbohydrate diets did not show any benefit on the risk of diabetes. However, this analysis is based on limited observational studies, and large-scale trials examining the complex interactions between low-carbohydrate diets and long-term outcomes are needed.