The over-the-counter supplement nicotinamide riboside, a form of vitamin B3, improved walking endurance in patients with peripheral arterial disease, a chronic leg condition that has few effective treatments.
In a pilot randomized, double-blind clinical trial led by scientists at Northwestern University and the University of Florida, patients who took nicotinamide riboside daily for six months increased their measured walking distance by more than 57 feet compared to participants taking a placebo. As expected, because peripheral arterial disease causes a progressive decline in walking ability, walking speed decreased in those taking the placebo.
“This is a signal that nicotinamide riboside may be effective in these patients,” said Dr. Christian Leeuwenberg, professor of physiology and gerontology at the University of Florida and senior author of the clinical trial report. “We hope to conduct larger follow-up studies to validate this finding.”
Leeuwenberg, whose research focuses on anti-aging therapeutics, collaborated with Mary M. McDermott, M.D., a physician and professor of medicine at Northwestern University and an expert on peripheral artery disease. Leeuwenberg and McDermott, along with a large collaborating team, published their findings in the journal Nature Communications on June 13.
Scientists recruited 90 patients with peripheral arterial disease (PAD) with an average age of 71 years to test the effects of nicotinamide riboside. The supplement is becoming increasingly popular as an anti-aging treatment, with sales in the United States alone exceeding $60 million in 2022, but there is little evidence of its effectiveness in healthy people. Nicotinamide riboside is a precursor to NAD, an essential compound that plays a role in the body in energy production, improving blood flow, and DNA repair.
Because PAD is linked to problems with energy production in muscle cells, McDermott and Leeuwenberg reasoned that nicotinamide riboside might improve energy production and, thereby, help patients with the disease walk better.
And that’s exactly what happened: After six months, subjects who took the supplement walked an average of 23 feet more in a six-minute walk test, while those taking the placebo walked 34 feet less. Subjects who took at least 75% of the pills they were supposed to take performed even better than those taking the placebo, walking over 100 feet more.
(The researchers also tested whether resveratrol, a compound well known to be found in red wine, could enhance the effects of nicotinamide riboside, but found no additional benefit.)
PAD affects more than 8.5 million Americans over the age of 40. Caused by the buildup of fatty deposits in the arteries and linked to diabetes and smoking, the disease reduces blood flow to the limbs, especially the legs. Walking is often painful, and the disease commonly leads to a decrease in walking ability over time. Supervised walking exercise is the first-line treatment for PAD, but most patients with the disease are unable to undergo supervised exercise.
In addition to larger trials focusing on PAD patients, Leeuwenberg hopes to test the effect of nicotinamide riboside on the walking ability of healthy older people.
“It needs to be tested in healthy older adults before we recommend it for healthy people,” he said.
June 18, 2024
