A new study led by Oregon Health & Science University (OHSU) and the Portland VA Health Care System has found that lipoic acid, an over-the-counter supplement, may slightly slow the loss of gray matter in people with progressive forms of multiple sclerosis (MS). However, researchers report that the supplement did not improve walking speed, which was the primary clinical outcome measured in the trial. The results were published on December 15 in Neurology.
The randomized controlled trial involved 54 participants with primary and secondary progressive MS who received a daily dose of 1,200 milligrams of lipoic acid for two years. Their outcomes were compared to those of 61 people given a placebo. While MRI scans indicated reduced brain atrophy among those taking lipoic acid, there was no significant improvement in walking speed or other main clinical measures.
"It didn't work clinically in progressive multiple sclerosis the way we hoped," said Rebecca Spain, M.D., M.S.P.H., associate professor of neurology at OHSU School of Medicine and co-director of the VA MS Center of Excellence West. "However, the slowing of brain atrophy that we saw in MRI images suggests that we may yet be on the right track, especially if we can find a better way to deliver the beneficial effects of an antioxidant like lipoic acid."
Multiple sclerosis is a disease that damages myelin—the protective covering around nerve fibers—in the central nervous system. This damage disrupts electrical signals necessary for movement, sensation, vision, and thinking. According to current estimates, about 2.8 million people worldwide are diagnosed with MS.
Researchers believe lipoic acid could offer anti-inflammatory and antioxidant benefits that might protect myelin and nerves if enough reaches the brain. Spain noted one challenge: "Lipoic acid is lipophobic," she said. "It does not cross the blood-brain barrier and get into the central nervous system very easily."
The recent study builds on earlier research involving animal models and smaller human trials dating back to a pilot study published in 2017. During this latest trial’s course, some participants experienced side effects associated with high doses; notably, two developed a kidney condition linked to medications including lipoic acid.
Despite these setbacks, researchers remain hopeful about future directions for treatment development. The findings are being incorporated into a larger project based in the United Kingdom called Optimal Clinical Trials Platform for Multiple Sclerosis (Octopus). This initiative will test both lipoic acid and metformin against placebos among more participants.
Spain emphasized collaboration between global research teams: "In combination with this Octopus trial, we are going to learn more about whether lipoic acid is worth taking if you have progressive MS," she said. "I am cautiously optimistic."
