For years, niacin — also known as vitamin B3 — was a go-to supplement for lowering cholesterol and improving heart health.
But new research raises the question: Could niacin actually do more harm than good when it comes to heart health?
We asked Michael Tao, MD, a cardiovascular medicine specialist with the Hartford HealthCare Heart & Vascular Institute, to dive into the latest science and shares what you should know before reaching for the bottle.
What is niacin?
Niacin, also called vitamin B3, is a water-soluble vitamin that plays a key role in your body.
“It’s essential for metabolism, helping convert food into energy,” explains Dr. Tao. “You’ll find it in a wide variety of meats and vegetables.”
Some common sources of niacin include:
- Meat products: Chicken, turkey, salmon, tuna, pork and beef are rich in niacin. Animal livers like beef or chicken liver have the highest levels.
- Plant-based options: Foods like rice, oats, peanuts, potatoes, sunflower seeds, mushrooms and avocados are all sources of niacin.
- Enriched foods: Many breads and cereals are fortified with niacin for an added boost.
- Energy drinks: Many popular energy drinks pack high doses of vitamins, including niacin.
Those looking for health benefits from niacin often take it as a supplement.
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Niacin lowers cholesterol, but may increase inflammation.
Niacin is essential for your body to function properly, and eating niacin-rich foods within the recommended daily intake helps prevent deficiency.
“It’s also believed to support cardiovascular health by improving cholesterol metabolism,” says Dr. Tao. “Niacin lowers bad cholesterol molecules like VLDL, LDL and triglycerides, while increasing good cholesterol molecules like HDL.”
But there’s more to the story.
“Research shows that excess niacin can be metabolized into byproducts that increase inflammation,” explains Dr. Tao. “This inflammation can damage blood vessels, promote plaque buildup and contribute to arterial disease—potentially offsetting its positive effects on cholesterol.”
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New studies suggest it may be harmful in large doses.
Taking more niacin than the recommended daily amount hasn’t been proven to benefit heart health—and newer studies suggest it could even be harmful.
“Since niacin is already present in so many everyday foods, fortifying products with additional niacin can easily lead to accidental overconsumption beyond the recommended 14-18 mg per day for adults,” explains Dr. Tao. “If someone regularly eats fortified cereals, breads or grains and takes a B-complex supplement, they could easily exceed the daily intake.”
Here are the potential effects of too much niacin:
- Flushing: Warmth and redness in the face, arms and chest.
- Liver strain: Excessive intake can lead to liver inflammation or injury over time.
- Other side effects include itching, headaches, nausea and vomiting.
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Some people are at higher risk of niacin complications.
Dr. Tao notes that some individuals may be at higher risk for niacin-related complications, especially those with the following conditions:
- Cardiac concerns: People with stable coronary artery disease or a history of heart attacks may be more susceptible to heart-related side effects.
- Blood pressure issues: High or low blood pressure can be impacted by niacin, as it dilates blood vessels, potentially causing drops in blood pressure.
- Liver health concerns: Since excess niacin is linked to liver injury, those with liver disease should avoid high doses.
- Stomach sensitivity: Niacin can irritate the stomach lining, making it unsuitable for those with gastric ulcers.
- Diabetes: Niacin can raise blood sugar, posing a concern for individuals with diabetes.
A doctor can advise you about niacin or any supplement.
While it’s an essential nutrient for metabolism and naturally found in many foods we eat daily, niacin’s benefits and risks can vary for everyone.
“If you’re unsure whether to take or avoid niacin, it’s best to consult your primary care doctor or cardiologist,” advises Dr. Tao. “Together, we can discuss how it may impact your health based on your medical history so you can make the right choice for you.”
