Peripheral neuropathy, the most common type of diabetic neuropathy, causes pain or loss of feeling in the toes, feet, legs, hands, and arms. Diabetic peripheral neuropathy affects as many as 50% of older type 2 diabetic patients. Some patients may have extremely painful symptoms, others with a more marked neuropathic deficit may be asymptomatic. Diagnosis requires careful examination of the lower limbs. Management involves establishing that the neuropathy is caused by diabetes, instead of more sinister causes, and aiming for optimal glycemic control. Medications, usually tricyclic drugs or anticonvulsant agents, are often used for symptomatic relief.[i]
The public health impact of diabetic peripheral neuropathy (DPN) is considerable. In the estimated global prevalence of diabetes of 472 million by 2030, DPN is likely to affect as many as 236 million people worldwide. In the United States alone, the total cost associated with DPN is $10.9 billion a year.[ii]
Clinical lore considers DPN difficult to treat, and often frustrates patients and physicians alike. While most treatment strategies have focused on the use of medications for symptomatic relief, relatively little attention has been paid to dietetic therapy. However, there is evidence for the efficacy of plant-based or vegan diets in the treatment of diabetic peripheral neuropathy.
Crane and Sample were able to achieve complete abatement of pain in 17 of 21 subjects placed on a vegan diet in only a month, with many patients achieving results in only 2 weeks. Long term results were maintained in 71% of patients even after four years. The authors state, “in our opinion, these results appear to be related to a factor(s) in the TVD [Total Vegetarian Diet, also known as vegan or plant-based diet], and not necessarily to an improved glucose control, since the serum glucose was not under good control until about the 10th day.”[iii]
The advantages of the total vegetarian diet are that it has been shown to be efficacious, benefits a variety of diabetic variables such as obesity and glycemic control, has no known side effects (compared with the anticholinergic and sedation side effects of tricylics and drugs such as gabapentin), and it is very cost effective.
It is important for clinicians to include supplemental vitamin B12 in any plant-based treatment regimen, but especially with older patients who are at greater risk of pernicious anemia. Some common diabetic medications such as metformin may also be B12 depleting.
[i] Boulton Andrew J.M. Management of Diabetic Peripheral Neuropathy. Clinical Diabetes January 2005 vol. 23 no. 1 9-15
[ii] Tesfaye S, Selvarajah D. Advances in the epidemiology, pathogenesis and management of diabetic peripheral neuropathy. Diabetes Metab Res Rev 2012 Feb;28 Suppl 1:8-14.
[iii] Crane MG, Sample C. Regression of diabetic neuropathy with total vegetarian (vegan) diet. J Nutr Med 1994;4:431–9.