WHO estimates that, globally, 422 million adults aged over 18 years were living with diabetes in 2014. In the UK, 2018 statistics state that almost 3.7 million people have been diagnosed with diabetes and 1 million cases remain undiagnosed. This has more than doubled over the last 20 years and 90% of cases will be type 2 diabetes. Another 12.3 million people are at risk of developing diabetes. This used to occur nearly entirely among adults, but now occurs in children too. The majority of type 2 diabetes cases are in fact preventable and often related to poor dietary and lifestyle choices. Diabetes is the leading cause of blindness and amputations in the UK.
Being overweight and especially central obesity, is strongly linked to type 2 diabetes. Therefore weight control through regular physical activity and a healthy balanced diet are important.
Observational studies show that prevalence of type 2 diabetes is lower in those following a healthful plant-based diet. Data from the Seventh-day Adventist Health Study (including 22,434 men and 38,469 women) found that as the intake of animal products decreased and consumption of plant-based products increased, there was a reduced prevalence of diabetes. Prevalence of type 2 diabetes decreased from 7.6% in non-vegetarians to 2.9% in vegans. This can be explained by the associated lower body mass index of individuals consuming a more plant-based diet.
Plant-based diets are suitable for people diagnosed with type 2 diabetes. Clinical intervention studies demonstrated that healthful vegetarian diets lead to a greater weight loss and greater reduction in fasting plasma glucose, HbA1c, blood lipids, and hypoglycemic medication than a conventional hypocaloric diet in subjects with type 2 diabetes.
Several possible mechanisms may explain the benefits of plant-based diets for diabetes management. Plant-based eating patterns are typically high in fibre, usually have a low energy density and low glycemic index, are low in saturated fat and high in unsaturated fat. Fibre, especially viscous fibre, is important as it helps glycemic control and may be useful in maintaining body weight.
Protein source seems also important in blood glucose management. Several intervention studies found that replacing sources of animal with plant protein foods (e.g., legumes, soya, nuts, etc.) leads to modest improvements in glycemic control in individuals with diabetes. Replacing animal protein with major sources of plant protein may be one strategy that can be combined with standard therapy to help improve and manage glycemic control in individuals with diabetes.
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