OTC supplement boosts walking for peripheral artery disease patients

A recent study has shown promising results for the over-the-counter supplement nicotinamide riboside, a form of vitamin B3, in enhancing the walking endurance of patients suffering from peripheral artery disease (PAD). PAD is a chronic condition characterized by reduced blood flow to the limbs, particularly the legs, leading to significant pain and a progressive decline in walking ability. There are currently limited effective treatments available for this condition.

The study, which was a preliminary, randomized, double-blind clinical trial, was spearheaded by researchers from Northwestern University and the University of Florida. Participants, who were administered nicotinamide riboside daily for six months, showed a marked improvement in their walking endurance. Specifically, these patients increased their walking distance by more than 57 feet compared to those who were given a placebo. In contrast, the walking speed of placebo recipients continued to decline, as is typical with the progression of PAD.

Dr. Christiaan Leeuwenburgh, a University of Florida professor who specializes in anti-aging treatments, and a senior author of the study, emphasized the significance of these findings. "This is a signal that nicotinamide riboside could help these patients," he said. He also expressed a desire to conduct a larger follow-up trial to further validate the results.

Leeuwenburgh collaborated closely with Dr. Mary M. McDermott, a Northwestern University physician and professor of medicine who is a leading expert in peripheral artery disease. Together with a robust team of researchers, they published their findings on June 13 in the journal Nature Communications.

The study involved 90 participants with an average age of 71, all diagnosed with PAD. Nicotinamide riboside has gained popularity as an anti-aging supplement, with sales in the U.S. surpassing $60 million in 2022. Despite its popularity, there has been limited evidence to support its efficacy in healthy individuals. The supplement acts as a precursor for NAD, an essential compound involved in energy production, improved blood flow, and DNA repair.

Given that PAD is linked to impaired energy production in muscle cells, McDermott and Leeuwenburgh hypothesized that nicotinamide riboside could potentially enhance walking performance in individuals with the disease. Their hypothesis was confirmed; participants taking the supplement showed a notable improvement in a six-minute walking test, walking an average of 23 feet more after six months, whereas those on the placebo walked 34 feet less. Those who adhered to at least 75% of their prescribed dosage exhibited even better results, covering over 100 additional feet compared to the placebo group.

The researchers also explored whether adding resveratrol, a compound commonly found in red wine, could amplify the effects of nicotinamide riboside. However, they found no additional benefits from combining the two compounds.

PAD affects over 8.5 million Americans aged 40 and above. The disease is primarily caused by the buildup of fatty deposits in arteries and is often associated with diabetes and smoking. The resultant poor blood flow to the extremities leads to pain and a gradual decline in walking capabilities. Although supervised walking exercise is the recommended therapy for PAD, access to such programs is limited for many patients.

In addition to planning a larger trial for PAD patients, Leeuwenburgh also intends to investigate the effects of nicotinamide riboside on the walking performance of healthy older adults. "We need to test it on a healthy older population before we recommend healthy people take it," he stated, highlighting the need for further research in this area.