Vegetarian Diets in the Prevention and Management of Diabetes and Its Complications

Abstract

IN BRIEF Epidemiological studies have found a lower prevalence of type 2 diabetes among vegetarians compared to nonvegetarians. This reduced risk is likely a function of improved weight status, higher intake of dietary fiber, and the absence of animal protein and heme iron in the diet. Interventional studies have shown that vegetarian diets, especially a vegan diet, are effective tools in glycemic control and that these diets control plasma glucose to a greater level than do control diets, including diets traditionally recommended for patients with diabetes (e.g., diets based on carbohydrate counting). Vegetarian diets are associated with improvement in secondary outcomes such as weight reduction, serum lipid profile, and blood pressure. Studies indicate that vegetarian diets can be universally used in type 2 diabetes prevention and as tools to improve blood glucose management.

Improving the scientific rigour of nutritional recommendations for adults with type 2 diabetes: A comprehensive review of the American Diabetes Association guideline‐recommended eating patterns

“…The ADA documents cite eight studies in support of a plant‐based diet (Table S7) for glycaemic control and CVD risk reduction. Of three RCTs, none found a significant improvement in HbA1c over the control diet, although, in all three, the test diet resulted in reductions from baseline for HbA1c as well as diabetes medication use, a significant factor in the diet's overall effectiveness.…”

“…In a review by Rinaldi et al whose conclusions favoured plant‐based diets, six trials did not consistently show improvements in glycaemic control, weight loss or CVD risk factors . The ADA also cited a commentary based on a non‐systematic review, a cross‐sectional study, and an assessment of diets in Barnard et al 2006. None of these studies was a controlled trial or systematic review.…”

“…We would like to note several things in the ADA documents that could be interpreted as evidence of bias, one of which is the inclusion of opinion pieces or reviews favouring the DASH, plant-based and Mediterranean eating patterns that were not based on a systematic approach to the literature. 22,47,48 Further, there seemed to be inconsistency in the ADA's determination of what constitutes sufficiently ample and rigorous evidence for its recommendations. For example, regarding glycaemic control, the ADA recommends the DASH diet on the basis of a single trial in T2D.…”

“…The ADA documents cite eight studies in support of a plant-based diet [47][48][49][50][51][52][53][54] (Table S7)…”

Vegan and Animal Meal Composition and Timing Influence Glucose and Lipid Related Postprandial Metabolic Profiles

“…Vegan, vegetarian, and animal‐based omnivorous diets are naturally health promoting if they are well‐balanced with sufficient macro and micronutrients to meet dietary requirements . Mediterranean, Nordic, and flexitarian (semi‐vegetarian) diets are omnivorous diets with an emphasis on plant‐based foods and have been shown to correlate with reduced risk of diabetes and cardiovascular disease onset and promote glucose and lipid control .…”