Researchers for a recent study reported that plant-based dietary patterns may be beneficial for the primary prevention of type 2 diabetes.
Researchers assessed PubMed, Medline, Embase, Web of Science, and reference lists through February 15, 2019, to identify prospective, observational studies that examined the association between adherence to plant-based dietary patterns and incidence of type 2 diabetes.
They selected nine English-language studies that included 307,099 adults, 23,544 of whom had type 2 diabetes.
Researchers observed a significant inverse association between higher adherence to a plant-based dietary pattern and risk of type 2 diabetes (RR=0.77; 95% CI, 0.71-0.84) compared with poorer adherence—indicating an average 23% risk reduction; there was modest heterogeneity across studies (P=0.07). This association was consistent regardless of age, sex, region, and body mass index.
When researchers used a fixed-effects model, the results were similar (RR=0.80; 95% CI, 0.75-0.84). The association between plant-based diet and prevention of type 2 diabetes was strengthened when healthy plant-based foods, such as fruits, vegetables, whole grains, legumes, and nuts, were included in the definition of “plant-based patterns” (RR=0.70; 95% CI, 0.62-0.79).
Most studies were deemed to be good quality in terms of dietary assessment, disease outcomes, and statistical adjustment for confounding factors.
The researchers said that clinical trials on plant-based diets have shown that these foods individually and jointly improve insulin sensitivity and blood pressure, reduce long-term weight gain, and ameliorate systemic inflammation, which are pathways involved in the cause of type 2 diabetes. These diets also deemphasize the consumption of red meat, which may increase the risk of gestational and type 2 diabetes.
The research is limited by its use of studies that included self-reported questionnaires on eating habits, which can introduce bias and misinformation. The researchers said more information is needed to determine whether this is a causal relationship. Read more