Diets rich in antioxidants associated with reduced type 2 diabetes risk, finds study

Scientists at the Karolinska Institute in Sweden conducted a systematic review and meta-analysis to determine the relationship between dietary antioxidant intake and type 2 diabetes risk.

The study was published in the journal Advances in Nutrition.

Type 2 diabetes is a metabolic disease marked by insulin secretion issues and elevated blood glucose levels. Its global prevalence exceeds 10%, fueled by poor dietary choices and sedentary lifestyles. Diet plays a pivotal role in regulating metabolism, among other lifestyle factors. Research suggests that adopting healthy eating patternscan substantially lower the risk of developing type 2 diabetes. These diets emphasize a higher intake of plant-based foods rich in antioxidants, including vitamins C, E, and beta-carotene, which are associated with improved metabolic health and reduced diabetes risk.

In the study, the scientists searched various electronic databases to identify studies investigating the association between dietary intakes, circulating levels, or supplementation of vitamin C, E, and beta-carotene and type 2 diabetes incidence or insulin resistance/sensitivity and beta cell function in non-diabetic individuals.The final screening led to the identification of 25 prospective observational studies and 15 randomized controlled trials. Moderate and serious risks of bias were observed in 21 and 4 observational studies, respectively. Among randomized controlled trials, 13 had a low risk of bias, and 2 had some concerns.

The study found that higher dietary and circulating levels of vitamins C, E, and beta-carotene are associated with a reduced risk of type 2 diabetes. However, supplementation with these antioxidants did not show a protective effect against diabetes. These vitamins exert their anti-diabetic effects through their antioxidant properties. Vitamin C, found in fruits and vegetables, removes free radicals in the body's water-soluble compartments and regenerates vitamin E which is present in nuts, seeds, and vegetable oils, prevents lipid peroxidation and protects cell membranes. Beta-carotene, found in fruits and vegetables, protects lipid components of the body from free radical damage, similar to vitamin E.

Reference:Anna-Maria Lampousi. 2024. Vitamins C, E, and beta-carotene and risk of type 2 diabetes: a systematic review and meta-analysis. Advances in Nutrition; https://www.sciencedirect.com/science/article/pii/S2161831324000450