Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD(+) in healthy middle-aged and older adults

Martens CR, Denman BA, Mazzo MR, Armstrong ML, Reisdorph N, McQueen MB · Nature Communications

NR was well tolerated and raised NAD+ in peripheral blood mononuclear cells by about 60 per cent against placebo (mean change 6.2 pmol/mg protein); NADP+ rose without reaching significance. Systolic pressure fell 3.9 mmHg and diastolic 2.0 mmHg on average, and carotid-femoral pulse wave velocity trended down, but none survived correction for multiple comparisons. Carotid compliance and flow-mediated dilation did not move. A post-hoc subgroup with elevated or stage I hypertension had systolic pressure 9 mmHg lower on NR, which the authors state carries no statistical inference.

Population

Healthy middle-aged and older adults

Intervention

Nicotinamide riboside 1,000 mg/day for 6 weeks, crossover

Comparator

Placebo

Limitations

Thirty enrolled and 24 in the cardiovascular analyses, six weeks per arm. Every cardiovascular signal is exploratory — the subgroup findings are post-hoc and the authors decline to draw inferences from them — and they were not confirmed by the follow-up trial designed to test them. NAD+ was measured in peripheral blood mononuclear cells, not in any tissue where the ageing argument is made.