Botanicals and dietary supplements in diabetic peripheral neuropathy

Many persons use botanicals and dietary supplements for chronic conditions that do not respond to traditional Western medications. Tricyclic antidepressants, a common treatment option for diabetic neuropathy, can have many side effects and are a poor choice in certain populations (eg, the elderly). As such, patients might turn to botanicals and dietary supplements, not realizing that these products are not well regulated.

This article reviews botanicals and dietary supplements that have been involved in randomized controlled trials (RCTs) for diabetic neuropathy. We searched MEDLINE for English-language literature dating from 1966 to April 2001 using the following subject headings: (1) diabetes and botanical, herb, and supplement, (2) neuropathy and botanical, herb, and supplement, and (3) diabetic neuropathy and botanical, herb, and supplement.

Our search found agents that might improve symptoms of neuropathy (eg, evening primrose oil, alpha-lipoic acid, capsaicin) without affecting glucose control. Botanicals and dietary supplements involved in only one RCT or associated with little clinical benefit were reviewed in brief.

Evening primrose oil, alpha-lipoic acid, and capsaicin have received the greatest attention for their use in diabetic neuropathy, but further studies are needed to confirm their efficacy. Patients using these products need to be informed of potential drug interactions and side effects.