1. Improves blood fat levels
Niacin may help to improve your blood fat levels by:
- increasing your HDL (good) cholesterol
- reducing your LDL (bad) LDL cholesterol
- reducing your triglyceride levels
This may translate to a decrease in heart disease risk, although several studies have found no link between niacin supplementation and a decrease in heart disease risk or deaths (4, 5).
It also takes high doses of niacin, typically 1,500 mg or greater, to achieve blood fat level improvements, which increases the risk of experiencing unpleasant or potentially harmful side effects (6).
For these reasons, niacin is not a primary treatment for high cholesterol. It’s primarily used to help improve blood fat levels in people who cannot tolerate statin drugs (5, 7).
2. May reduce blood pressure
One role of niacin is to release prostaglandins, or chemicals that help your blood vessels widen — improving blood flow and reducing blood pressure. For this reason, niacin may play a role in the prevention or treatment of high blood pressure (8).
In one observational study of over 12,000 adults, researchers found that each 1 mg increase in daily niacin intake was associated with a 2% decrease in high blood pressure risk — with the lowest overall high blood pressure risk seen at a daily niacin intake of 14.3 to 16.7 mg per day (8).
A high quality study also noted that single doses of 100 mg and 500 mg of niacin slightly reduced right ventricular systolic pressure (9).
However, more research is needed to confirm these effects.
3. May help treat type 1 diabetes
Type 1 diabetes is an autoimmune disease in which your body attacks and destroys insulin-creating cells in your pancreas.
There’s research to suggest that niacin could help protect those cells and possibly even lower the risk of type 1 diabetes in children who have a higher chance of developing this condition (10).
However, for people with type 2 diabetes, the role of niacin is more complicated.
On one hand, it can help lower the high cholesterol levels that are often seen in people with type 2 diabetes. On the other, it has the potential to increase blood sugar levels. As a result, people with diabetes who take niacin to treat high cholesterol also need to monitor their blood sugar carefully (11).
Fortunately, a more recent review of studies found that niacin did not have significant negative effects on blood sugar management in people with type 2 diabetes (12).
4. Boosts brain function
Your brain needs niacin — as a part of the coenzymes NAD and NADP — to get energy and function properly.
In fact, brain fog and even psychiatric symptoms are associated with niacin deficiency (1, 13).
Some types of schizophrenia can be treated with niacin, as it helps undo damage to brain cells that’s caused by a niacin deficiency (14).
Preliminary research shows that it could also help keep the brain healthy in cases of Alzheimer’s disease. However, results are mixed (15, 16).
5. Improves skin health
Niacin helps protect skin cells from sun damage, whether it’s used orally or applied as a lotion (17).
It may help prevent certain types of skin cancer as well. One high quality study in over 300 people at high risk of skin cancer found that taking 500 mg of nicotinamide twice daily reduced rates of nonmelanoma skin cancer compared to a control (18).
Summary
Niacin can help treat many conditions. It appears to exert positive effects on blood fat and blood pressure levels, and may play a role in type 1 diabetes, brain health, and skin cancer prevention. However, more research is needed.