Can Dietary Niacin Reduce the Risk of Heart Disease?

Niacin, or vitamin B3, is found in foods and can also be used as an inexpensive suppelment.  Studies in the 1970s (Coronary Drug Project) showed that supplemental niacin used in heart patients improved outcomes, presumably due to the favorable impact on cholesterol.  In the last decade, supplemental niacin has become less popular for use to control cholesterol particles but is still an effective option selected at the Kahn Center, particularly for patients with an elevated Lipoprotein (a).  

Recently, researchers at the Cleveland Clinic raised questions about the safety of even the small doses of niacin added to food items to prevent pellagra.

A new study recently published examined dietary niacin intake and heart outcomes. The results are reassuring. 

STUDY

From 2003 to 2018, the researchers continually investigated updated information from the National Health and Nutrition Examination Survey (NHANES). Based on the quartiles of niacin intake levels, four distinct categories of participants were established: Q1 (<14.646 mg), Q2 (14.646-21.302 mg), Q3 (21.302-30.401 mg), and Q4 (>30.401 mg).

RESULTS

The cohort analysis included 80,312 participants for the assessment of niacin intake.

Comparing the Q1 (lowest niacin) to the Q4 (highest niacin) dataset in the overall population, there was an 18% lower  all-cause mortality and a 20% mortality owing to cardiovascular disease in the highest niacin group.

When the data was analyzed by gender, niacin intake benefited women but was not significantly correlated with prevalence, all-cause mortality, or death from cardiovascular disease in males.

CONCLUSIONS

Higher niacin consumption was correlated with a decreased risk of cardiovascular disease and death from all causes across the entire study population. Nevertheless, only females, and not males, exhibited a beneficial effect on mortality when the data was analyzed by gender. It is unclear why women seemed to have an advantage over men in terms of niacin. 

Niacin is widely available over the counter and inexpensive. The safest forms seem to be the immediate release form, often bringing on an intense flushing, and extended release forms like Endur-acin used at the Kahn Center and better tolerated. We have observed major drops in both cholesterol and Lipoprotein(a) levels with even low doses of niacin. Careful attention to side effects and follow up labs for liver enzymes, uric acid, and blood sugar is suggested.  At the Kahn Center, we usually use niacin without concomittant statin medications. 

It is reassuring to note the lower cardiovascular outcomes related to dietary niacin intake. The data are consistent with the Coronary Drug Project and other pioneering studies done decades ago.