Can a Vegan Diet Reduce Diabetic Neuropathic Pain?

Diabetic polyneuropathy (DPN) often incurs pain that is treatment resistant. A recent review sought to examine if a whole‐food, plant‐based diet had a positive effect on individuals with type 2 diabetes (T2D) and DPN.

Although additional research is needed, the authors said a vegan diet is one that providers should consider, given the improved pain management, glycemic control, and reduced need for medication.

The lifetime prevalence of DPN is about 50% and is linked with significant illness, including foot ulcers, amputations, anxiety, depression, and reduced quality of life. Other research has identified that a 30% reduction in pain intensity is considered a “meaningful” reduction but that many find that unsatisfactory.

Researchers searched PubMed and Google Scholar for the keywords “plant‐based,” “vegetarian,” “vegan,” “diet,” and “diabetic neuropathy." From an initial 1613 articles retrieved, only 3 were included in the analysis, based on the eligibility criteria. One of the 3 was the seminal 1994 study that examined the effect of a vegan diet, along with exercise and other factors, on neuropathic pain in 21 people with T2D.

Most of the participants were obese and were instructed to follow a low-fat, low-calorie diet for 25 days. They also had to undertake moderate exercise for 30 minutes a day.

More than 80% of the patients reported complete pain relief within 4 to 16 days. Approximately 85% reported significant weight loss, and glycemic control improved for most. Five of 21 patients were able to stop using insulin while the remaining patients saw an average reduction of 54% in insulin or another hypoglycemic agent.

A similar study, in 2015, of 34 patients saw comparable results. These individuals also followed a restricted diet, and both the intervention group and the control group took 1000 mcg of methylcobalamin per day. The intervention group also had cooking classes and other support.

Those who followed the diet for 20 weeks had significantly lower pain scores on the Short Form McGill Pain Questionnaire, and their weight dropped as well.

The third study was a case report of a female patient, aged 51, with uncontrolled hypertension, pulmonary hypertension, and T2D; her baseline hemoglobin A1c was 15.1%. She took gabapentin for severe diabetic neuropathy in both feet and was on including pulmonary arterial vasodilators and diuretics for her other issues. She switched her diet to a vegan one and within 15 months, her hemoglobin A1c levels dropped from 15% to 5.6%. She also was able to stop using gabapentin and diabetes medications and lost about 50 kg.

What is not known, however, are the exact molecular mechanisms by which a vegan diet can lead to such improvements in pain reduction, weight, and other factors in T2D. One might be improved blood flow and optimized intake of nutrients, which could lead to improved perfusion in the endoneurial microvasculature, the authors said.

Reference

Storz MA, Küster O. Plant‐based diets and diabetic neuropathy: A systematic review. Lifestyle Med. Published September 30, 2020. doi:10.1002/lim2.6