Vegan diet impacts incretin and insulin in type 2 diabetes patients, study suggests

The new findings suggests clinical applications of vegan diets for improvement of beta-cell function and diabetes treatment, according to researchers.

The randomised crossover study, published in Nutrients​, compared the responses of 20 men aged 30 to 65 diagnosed with T2D to energy-matched vegan and non-vegan burger meals.

Researchers tracked their improvement via glucose response monitoring and beta-cell function.

Findings revealed the secretion of insulin, C-peptide, and amylin increased more after the vegan meal than the standard meal. Beta-cell function parameters also improved after the vegan meal.

The report states that a“Single plant-based meal can increase postprandial insulin secretion, which has direct implication for diabetes treatment. Preserving the capacity of beta-cells to produce insulin according to changing need is a cornerstone in the treatment of diabetes.​

“Insulin secretion and beta-cell function may be improved by different treatment options that lower body fat (such as diet and exercise, GLP-1 agonists, or bariatric surgery) or change fat distribution (such as thiazolidinediones).​

“As medications and bariatric surgery are expensive and introduce potential side effects, lifestyle interventions should be the first-choice treatment.​

“It has been demonstrated that a 16-week vegan diet improves insulin resistance and beta-cell function in overweight individuals, addressing both core pathophysiologic mechanisms involved in diabetes at the same time.”​

The researchers note that plant-foods are naturally rich in fibre, which may have influenced postprandial insulin levels.

They also point out that micronutrients, such as zinc, polyphenols​, and other phytochemicals may also have played their positive role in postprandial incretin and insulin secretion.

Hormones and diabetes​

Gastrointestinal hormones play a key role in glucose metabolism​​, energy homeostasis, satiety, and regulation of body weight.

Incretin hormones, namely glucagon-like peptide -1 (GLP-1) and gastric inhibitory peptide (GIP), which are released from the small intestine in response to nutrient ingestion to enhance glucose-dependent insulin secretion, aid in the overall maintenance of glucose homeostasis​​.

Furthermore, GLP-1​​ , and amylin​​ play a role in energy intake through appetite regulation. 

Plant diet studies​

Previous studies​​ have shown a plant-based diet can help support the mood of people with type 2 diabetes 

A 19-year study​​ in 2017 suggested that those consuming diets rich in vegetable proteins have reduced levels of type 2 diabetes (T2D) compared to those consuming similar protein quantities from meat. 

A 16-week plant-based diet intervention study last year found this diet led to increases in meal-stimulated insulin secretion and pancreatic beta-cell glucose sensitivity​ ​in overweight adults. ​Compared with controls, the plant-based diet group also had lower fasting insulin resistance and decreased fasting and postprandial blood glucose levels.

Source: Nutrients​
Published online ahead of print, doi: 10.3390/nu11030486​​“A plant-based meal stimulates incretin and insulin secretion more than an energy- and macronutrient-matched standard meal in type 2 diabetes: a randomized crossover study.“​
Authors: Kahleova H, Tura A, Klementova M, et al.