We reviewed the evidence about the effects of niacin for the prevention of death and cardiovascular disease.
Heart attack and stroke are the most common causes of death, illness, disability and reduced quality of life in industrialised countries.
Niacin (nicotinic acid, vitamin B3) was considered a promising candidate to prevent cardiovascular disease because it is known to lower cholesterol in the blood, which is one of the main risk factors. Therefore, long-term therapy with niacin was assumed to reduce the risk of heart attack, and stroke. We assessed whether clinical studies could show a benefit of taking niacin.
We found 23 studies including 39,195 participants that compared niacin to placebo. The evidence is current up to August 2016. The majority of included participants were on average 65 years old and had already experienced a myocardial infarction. The participants took niacin or placebo for a period of between six months and five years. Seventeen out of 23 studies were fully or partially funded by the drug manufacturer with a commercial interest in the results of the studies.
Niacin did not reduce the number of deaths, heart attack or stroke. Many people (18%) had to stop taking niacin due to side effects. The results did not differ between participants who had or had not experienced a heart attack before taking niacin. The results did not differ between participants who were or were not taking a statin (another drug that prevents heart attack and stroke). The overall quality of evidence was moderate to high.
In summary, we found no evidence of benefits from niacin therapy.