A review of the research looking at legume consumption and blood glucose management in people with and without diabetes has found that eating legumes regularly may have a beneficial effect on markers of blood glucose management in people with type 2 diabetes.
Legumes are a good source of dietary fibre, plant protein and low GI carbohydrate, and research has found evidence of improved blood glucose levels after single meals containing legumes. However, the effects of regular longer-term consumption of legumes are less clear. A group of Australian researchers therefore set out to determine whether habitual intake of legumes has a beneficial effect on blood glucose management in the medium to longer-term.
They combined the findings from 18 randomised controlled trials, 5 in individuals with type 2 diabetes, 12 in those without diabetes and 1 in people with prediabetes. The intake of legumes in the studies ranged from 50 – 285 g (1.76 – 10 oz) per day, and included several different types including chickpeas, lentils and a variety of beans. People in the control groups were asked to avoid or minimise their consumption of legumes. The studies ranged between 6 and 16 weeks.
The researchers found evidence of consistent improvements in blood glucose management in people with type 2 diabetes who consumed the legume-based diets. Three studies showed reductions in fasting blood glucose, two studies found reductions in HbA1c (which reflects average blood glucose levels over the past 3 months), one study found a reduction in fasting insulin, and another showed a reduction in blood glucose levels 2 hours after meals.
The studies in people without diabetes didn’t find a consistent benefit for legume consumption on markers of blood glucose management, and the study in individuals with prediabetes also showed no statistically significant benefits.
The researchers conclude that regular legume consumption for at least 6 weeks may significantly improve several markers of blood glucose management in individuals with type 2 diabetes. However, they caution that the evidence is of low quality. While their findings support the regular inclusion of legumes in the diet of people with type 2 diabetes, they suggest that further high-quality, longer term randomised control trials are needed. They also call for more research in those with prediabetes, gestational diabetes and type 1 diabetes are as there are few studies looking at legume intake in these groups of people.
- Bielefeld and colleagues. The Effects of Legume Consumption on Markers of Glycaemic Control in Individuals with and without Diabetes Mellitus: A Systematic Literature Review of Randomised Controlled Trials. Nutrients. 2020.
Dr Kate Marsh is an is an Advanced Accredited Practising Dietitian, Credentialled Diabetes Educator and health and medical writer with a particular interest in plant-based eating and the dietary management of diabetes and polycystic ovary syndrome (PCOS).
Contact: Via her website www.drkatemarsh.com.au