Niacin occurs naturally in foods such as milk, nuts, eggs, meat and poultry. Doctors may also prescribe niacin in large doses of up to 1,000 mg to 2,000 mg a day to improve cholesterol. A large multi-year government study about niacin and cholesterol ended early because risks associated with taking large doses of niacin proved more harmful than helpful. If you take or plan to take niacin to lower cholesterol, discuss concerns about safety and effectiveness with your doctor.
High Cholesterol
Three types of lipids in your bloodstream comprise your total cholesterol: low-density lipoprotein, high-density lipoprotein and triglycerides. You face higher risk of developing cardiovascular disease if your LDL cholesterol measures more than 160 mg/dl or your triglycerides measure more than 200 mg/dl -- milligrams per deciliter of blood. HDL cholesterol, also known as the "good" cholesterol, helps pull LDL cholesterol and triglycerides out of your system. Healthy HDL levels measure above 60 mg/dl.
Niacin and Cholesterol
Changes in your diet and lifestyle may help you reduce your LDL -- "bad" cholesterol -- and triglycerides, a type of fat that acts similarly to LDL cholesterol in your arteries. Both can accumulate to unhealthy levels. If you cannot improve your cholesterol levels enough by exercising and adopting a low-fat, low-sugar diet, your doctor may prescribe a medication such as statins to lower LDL cholesterol. Your physician may also suggest you take niacin, known to lower triglycerides and raise HDL cholesterol, according to the National Institutes of Health. Healthier triglyceride and HDL cholesterol levels should help protect you against heart disease, but a government study did not produce anticipated results.
Niacin Study
The National Institutes of Health announced on May 26, 2011 the early end of a study to test the effectiveness of niacin on heart health. About half of the 3,414 participants in the study took statins, a cholesterol-lowering medication, along with niacin, also known as vitamin B. Although the combination therapy worked to lower triglycerides and elevate HDL, it did not help protect participants against heart disease. Persons who took high doses of niacin -- 2,000 mg a day -- experienced as many heart attacks as persons who did not take niacin. Participants who took high doses of niacin also suffered more strokes -- 28 as compared to 12 among persons who took a placebo.
Considerations
The higher incidence of strokes may prove coincidental, according to the NIH. And, if you currently take niacin to improve your cholesterol, do not stop taking it without consulting your physician. Earlier studies testing the effectiveness of niacin produced more promising results, but those studies did not specifically test the relationship between niacin, elevated HDL levels and cardiovascular disease. Some studies similar to the NIH study remain under way.
References
- CBC News; Niacin Trial For Heart Disease Stopped Early; May 27, 2011
- National Institutes of Health: NIH Halts Clinical Trial on Combination Cholesterol Treatment; May 26, 2011
- MayoClinic.com; High Cholesterol: Niacin to Boost Your HDL, Good,' Cholesterol;June 6, 2009
- MayoClinic.com; High Cholesterol; June 24 2010
