People with multiple sclerosis (MS) are being warned against taking resveratrol supplements, after a new study using two MS models has found that the compound worsened MS-like neuropathology and inflammation, and had no neuroprotective effects.

Results of the study were published in The American Journal of Pathology.

Reservatrol is a naturally occurring polyphenol compound found in the skin of red grapes, red wine and peanuts, and it is believed to have anti-inflammatory and antioxidant properties.

This has been supported by some experimental studies, whereas others suggest a lack of benefit.

Lead investigator Dr. Ikuo Tsunoda, assistant professor in the Department of Microbiology and Immunology at the Center for Molecular & Tumor Virology of the Louisiana State University Health Sciences Center, says:

"Resveratrol may have detrimental effects in some disease conditions and should be discouraged for supplemental use by MS patients pending further research."

Effects of resveratrol in mice

The researchers tested resveratrol in autoimmune and viral models of MS in mice.

In the autoimmune model, they simulated an experimental autoimmune encephalomeylitis (EAE) using myelin oligodendrocyte glycoprotein peptide. The mice were then fed either a control diet or a diet containing resveratrol.

After 12 days, the mice all showed clinical signs, such as tail and hind limb paralysis, and the symptoms worsened and peaked by 3 weeks.

After 5 weeks, the mice eating the control diet recovered completely or suffered only mild paralysis, whereas mice on the resveratrol diet all exhibited severe and lasting EAE without remission.

Neuropathological tests on the spinal cords of the mice also showed higher pathology scores for demyelination, meningitis and inflammation for those fed the resveratrol diet. There was no evidence that resveratrol suppressed autoimmune responses, leading the researchers to conclude that it did not have any anti-inflammatory properties.

Further experiments conducted to test whether resvertrol had any anti-viral properties again cast doubt about the claims.

Mice were infected with the Daniels (DA) strain of Theiler's murine encephalomyelitis virus (TMEV) to induce TMEV-induced demyelinating disease (TMEV-IDD).

The findings here showed that the mice fed on the resveratrol diet developed significantly more severe TMEV-IDD than the control group.

The degree to which resveratrol exacerbated demyelination and inflammation surprised the research team.

"Our findings illustrate that caution should be exercised for potential therapeutic application of resveratrol in human inflammatory demyelination diseases, including MS," says Dr. Tsunoda.

The jury is still out on any benefits resveratrol may have. Recent studies have shown it is effective in treating vascular dementia, but a 2012 study queried any benefits for healthy women.