In a pilot study, researchers found that taking a high dose of lipoic acid every day for 2 years reduced whole brain atrophy among patients with secondary progressive multiple sclerosis (SPMS), compared with a placebo.
Lead study author Dr. Rebecca Spain, of the Oregon Health & Science University School of Medicine in Portland, and colleagues recently reported their results in the journal Neuroimmunology & Neuroinflammation.
Multiple sclerosis (MS) is a progressive neurological condition that is estimated to affect more than 2.3 million people across the globe.
In MS, the immune system mistakingly attacks myelin, which is the protective coating of nerve fibers in the central nervous system. This interferes with nerve signaling between the brain and spinal cord, causing weakness, walking difficulties, and numbness or tingling of the face, body, or limbs, among other symptoms.
Relapsing-remising MS (RRMS) is the most common form of MS, in which a patient experiences flare-ups (relapses), followed by periods of few or no symptoms (remissions).
The majority of people with RRMS will progress to SPMS, wherein nerve damage or loss worsens, symptoms become more severe, and periods of remission become less frequent.
There is currently no cure for SPMS, but there are disease-modifying therapies available that may help to slow disease progression.
Dr. Spain and colleagues suggest that lipoic acid - a naturally occurring antioxidant that is available as an over-the-counter supplement - could be an effective treatment for SPMS, after finding that it helped to reduce the rate of whole brain atrophy among patients with the condition.
Lipoic acid outperformed ocrelizumab
Whole brain atrophy refers to the reduction in total brain volume due to the loss of neurons, and it is considered a marker of MS progression.
For their randomized, double-blind study, Dr. Spain and team enrolled 51 adults aged between 40 and 70 years, all of whom had been diagnosed with SPMS.
A total of 27 participants were randomized to receive 1,200 milligrams of lipoic acid every day for 2 years, while the remaining 24 subjects received a placebo.
The brain volume of each participant was assessed at study baseline using MRI. MRI scans were also conducted each year thereafter, in order to pinpoint any changes in subjects' brain volume.
Compared with participants who took the placebo, the researchers found that those who took lipoic acid showed a 68 percent reduction in the rate of whole brain atrophy.
For comparative purposes, the team notes that the drug ocrelizumab (brand name Ocrevus) - which was recently approved by the Food and Drug Administration (FDA) for the treatment of primary progressive MS - improved whole brain atrophy by 18 percent in clinical trials.
What is more, the new study revealed that participants treated with lipoic acid experienced fewer falls and better walking times, compared with subjects who received the placebo.
Importantly, the researchers found that lipoic acid was generally safe and well tolerated by participants, with the most common side effect being gastrointestinal upset.
However, the team cautions that further trials in a larger number of patients are needed before lipoic acid can be recommended as a safe and effective treatment for MS.
"These are high doses. And while it seems safe, we won't know whether it actually improves the lives of people with MS until we can replicate the results in the pilot study through a much bigger clinical trial."
Dr. Rebecca Spain
"Fortunately, we're going to be able to answer that question with the participation of kind volunteers," adds Dr. Spain.
Using the results of their pilot study, the researchers are currently designing a multisite clinical trial that is due to start later this year.