NR can mimic the calorie restriction usually achieved only by fasting and kick-start the same chemical pathways that can reverse physiological signs of ageing. The supplement also improves blood pressure levels and so helps improve arterial health, so it could be especially useful for people suffering from mild hypertension (high blood pressure), say researchers at the University of Colorado.
Although researchers have investigated the health benefits of fasting—where food intake is reduced by at least one-third—it's the first time anyone has properly tested the benefits of the NR supplement on people.
The researchers recruited 24 healthy men and women, aged from 55 to 79, who were either given a placebo for six weeks or instead took a 500 mg NR supplement twice a day. Blood samples revealed that after taking NR, there had been an increase in an enzyme that protects the body from stress; levels of the enzymes, sirtuins, usually decrease as we age.
The supplements also reduced the blood pressure in the volunteers who had mild, and early-stage, hypertension; on average, it reduced blood pressure levels by around 10 points, which would translate into a 25 per cent reduction in heart attack risk, the researchers estimated.
More research needs to be done, say the researchers, and don't give up on a good diet and exercise even if you are taking NR supplements, they say.