What is Niacin?
Niacin, a.k.a. vitamin B3, is a water-soluble B vitamin essential for various bodily functions. According to the National Institutes of Health (NIH). Niacin is necessary for energy metabolism, the breakdown of fatty acids, DNA repair, cell signaling, and antioxidant defense. It is found in foods like chicken, turkey breast, salmon, and sunflower seeds, and is often added to flour and fortified cereals to prevent nutritional deficiencies.
The recommended dietary allowance for niacin is 16 milligrams for adult men and 14 milligrams for adult women.
Niacin and Heart Health: A Complicated Relationship
Niacin has historically been used in prescription medications to lower high cholesterol levels. Medications like Niaspan, which contain extended-release niacin, were prescribed to deliver doses ranging from 500 to 1,000 milligrams. However, the efficacy of niacin in reducing cholesterol and preventing heart disease has been questioned in recent years.
Dr. Stanley Hazen, co-author of the new study and chairman of the Department of Cardiovascular & Metabolic Sciences at the Cleveland Clinic, emphasizes that niacin is critical for health but is no longer commonly used as a cholesterol-lowering medication due to the availability of more effective alternatives.
The Study’s Findings: Niacin and Heart Disease Risk
The recent study in Nature Medicine analyzed blood samples from 1,162 individuals evaluated for heart disease. Researchers discovered that high levels of niacin could trigger inflammation and damage blood vessels, leading to an increased risk of heart disease. They identified a substance called 4PY, produced when there is an excess of niacin in the body, which was strongly linked to patients who had experienced heart attacks, strokes, or other cardiac events. The study found that 4PY directly caused vascular inflammation, damaging blood vessels and potentially leading to atherosclerosis.
Who Should Avoid Niacin?
Given the study’s findings, Dr. Cheng-Han Chen, a board-certified interventional cardiologist, advises caution regarding routine niacin supplementation, especially in large doses. He stresses the need for further research to determine safe dosage levels.
Nutrition expert Scott Keatley points out that typical dietary intake of niacin through fortified foods is unlikely to pose a risk. The study involved much higher doses, from 500 to 2,000 milligrams, far exceeding the recommended dietary allowances.
The Benefits of Niacin
Despite the concerns raised by the study, niacin has several established benefits, particularly when consumed in low doses. It supports energy metabolism, neurological function, and skin health. At higher doses, it has been used to manage high cholesterol and triglyceride levels, although its use for these purposes should be closely monitored by a healthcare provider.
Niacin and Clogged Arteries
The role of niacin in preventing clogged arteries is complex. Earlier research suggested that niacin could reduce plaque buildup by raising HDL (“good”) cholesterol levels. However, more recent studies, including an analysis of 35,760 patients from 17 clinical trials, have shown that niacin does not significantly prevent serious heart-related events and may even increase overall mortality.
Expert Recommendations
For individuals currently taking niacin for heart disease prevention, Dr. Chen recommends consulting with their healthcare provider before making any changes. He emphasizes that it is too early to make definitive recommendations about avoiding niacin based on the new study alone.
Keatley and Dr. Hazen agree that it is best to obtain vitamins from food sources rather than supplements and to avoid excessive intake. They advise focusing on a balanced diet rich in fruits and vegetables while avoiding excess carbohydrates.
Disclaimer
Dietary supplements are intended to supplement the diet and are not medicines. They should not be used to treat, diagnose, mitigate, prevent, or cure diseases. Pregnant or nursing women and children should use supplements only under the recommendation of a healthcare provider.
Conclusion
The evolving science of nutrition continues to uncover new insights into the effects of vitamins and supplements on health. The recent study on niacin highlights the importance of cautious and informed use of dietary supplements. Individuals should consult with their healthcare providers and prioritize a balanced diet to maintain optimal health.
