Moderate vitamin E, C, and β-carotene intake decreases type 2 diabetes risk

A recent study published in Advances in Nutrition examines the impact of vitamins C and E, as well as β-carotene, on type 2 diabetes (T2D) risk.

The study focused on randomized controlled trials (RCTs) and dose-response relationships, unlike previous meta-analyses. Data from Embase, MEDLINE, and the Cochrane Library were reviewed, yielding 40 eligible articles out of 6,190.

T2D is linked to β-cell dysfunction and insulin resistance, with dietary patterns like the Mediterranean diet showing protective effects. This diet emphasizes fruits, vegetables, olive oil, and fish, rich in antioxidants like vitamins C, E, and β-carotene.

Antioxidants combat oxidative stress, a factor in insulin resistance. While vitamin C intake inversely correlates with insulin resistance, RCTs show mixed results for vitamin supplementation's impact on T2D risk.

Moderate dietary intake of these vitamins, meeting Nordic guidelines, appears optimal. Mendelian randomization analyses didn't establish a causal link between genetically predicted antioxidant levels and T2D.

While these antioxidants may act synergistically in the Mediterranean diet, supplementation isn't recommended as a preventive measure for T2D in healthy individuals. Further research is needed for optimal antioxidant intake among specific groups.