Increased levels of a common vitamin previously recommended to lower cholesterol has been linked to a process in the body that contributes to heart disease, a new study has found.
Researchers have discovered a link between high levels of a breakdown product of excess niacin – vitamin B-3 – and heart disease.
They also found that this breakdown product, 4PY, leads to damage to the blood vessels as it causes vascular inflammation, which can lead to atherosclerosis – the build-up of fats and cholesterol in the artery walls.
The team’s discoveries pave the way for potential interventions to stop or reduce this inflammation.
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Dr Stanley Hazen, Chair of Cardiovascular and Metabolic Sciences at Cleveland Clinic’s Lerner Research Institute, led the research.
He said: “What’s exciting about these results is that this pathway appears to be a previously unrecognised yet significant contributor to the development of cardiovascular disease.
“What’s more, we can measure it, meaning there is potential for diagnostic testing. These insights set the stage for developing new approaches to counteract the effects of this pathway.”
For years, more than 50 countries have added niacin to food items including flour, cereals and oats to prevent nutritional deficiency.
However, in Dr Hazen’s study, one in four people were getting too much niacin, and had increased levels of 4PY, which appear to be linked to the development of heart disease.
Dr Hazen said consuming too much niacin is like having several taps pour into a bucket all at once – when the bucket fills up, it begins to spill over.
To process of an overspill of niacin, the body produces metabolites such as 4PY.
Dr Hazen warned against cutting out niacin completely but said: “Given these findings, a discussion over whether a continued mandate of flour and cereal fortification with niacin in the U.S. could be warranted.”
Niacin was one of the original treatments for lowering the ‘bad’ cholesterol, LDL.
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However, in time, niacin was found to be less effective than other treatment and was linked to negative side effects and increased mortality rates.
Dr Hazen said: “Niacin’s effects have always been somewhat of a paradox. Despite niacin lowering of cholesterol, the clinical benefits have always been less than anticipated based on the degree of LDL reduction.
“This led to the idea that excess niacin caused unclear adverse effects that partially counteracted the benefits of LDL lowering. We believe our findings help explain this paradox. This illustrates why investigating residual cardiovascular risk is so critical; we learn so much more than what we set out to find.”
Dr Hazen said that over-the-counter supplements containing different forms of niacin have become popular in recent years due to presumed anti-aging effects, so he advised people to check with their doctors first before taking such supplements.
Read the full study in Nature Medicine.