A natural dietary supplement called nicotinomide riboside mimics caloric restriction and improves blood pressure and arterial health, particularly in those with mild hypertension, according to a small pilot study published Thursday.
A natural dietary supplement called nicotinomide riboside (NR) mimics caloric restriction and improves blood pressure and arterial health, particularly in those with mild hypertension, according to a small pilot study published Thursday.
The study, published in Nature Communications, included 24 lean and healthy men and women aged 55 to 79 years. Senior author Douglas R. Seals, PhD, said it is the first study to give NR, a form of vitamin B3, over a period of time. Participants reported no serious adverse effects.
Half were given a placebo for 6 weeks, then took a 500 mg twice daily dose of NR chloride, which is currently sold as a supplement. The other half took NR for the first 6 weeks, followed by placebo.
The University of Colorado Boulder researchers took blood samples and other physiological measurements at the end of each treatment period. They found that 1000 mg of NR daily boosted levels of another compound called nicotinamide adenine dinucleotide (NAD+) by 60%.
NAD+ is needed for activation of enzymes called sirtuins, which are linked to the beneficial effects of calorie restriction. Involved in metabolic actions throughout the body, it declines as part of the aging process. As an evolutionary survival mechanism, the body conserves NAD+ when subjected to calorie restriction. But only recently have scientists begun to explore the idea of supplementing with so-called "NAD+ precursors" like NR to promote healthy aging.
Although NR is currently on the market, the researchers stressed that the amount consumed in the study is more than the present label-recommended dose. The type used in the study was made by the nutraceutical company ChromaDex, which also provided the supplements and financial support.
The study was also funded by the NIH and the American Federation for Aging Research.
The study also found that in 13 participants with elevated blood pressure or stage 1 hypertension (120-139/80-89 mm Hg), systolic blood pressure was about 10 points lower after supplementation. A drop of that magnitude could translate to a 25% reduction in heart attack risk.
"If this magnitude of systolic blood pressure reduction with NR supplementation is confirmed in a larger clinical trial, such an effect could have broad biomedical implications," the authors note.
Compounds that mimic the effects of caloric restriction could provide an additional option for patients whose blood pressure is not yet high enough for medication but who are still at risk for a heart attack. It would not be a replacement for recommended dietary changes and exercise for good health.
No improvement was found in blood glucose control or insulin sensitivity,
"We are not able to make any definitive claims that this compound is safe or going to be effective for specific segments of the population," said lead author Christopher R. Martens, PhD, now an assistant professor at the University of Delaware.
Martens and Seals have applied for a grant to conduct a larger clinical trial looking specifically at the impact of NR supplementation on blood pressure and arterial health. Martens is also launching a separate trial looking at the impact NR has on older adults with mild cognitive impairment.
Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9:1286. doi: 10.1038/s41467-018-03421-7.