Niacin May Lower Cholesterol Without Affecting Glucose Levels

The B vitamin niacin (nicotinic acid) is well-known to positively affect cholesterol levels, particularly by increasing levels of HDL cholesterol, but is not currently recommended for diabetic patients due to concerns that it might adversely impact upon control of blood glucose levels.

However, the authors of a new study note that this recommendation is not based upon adequate evidence, so they decided to investigate further both the safety and efficacy of niacin in diabetic patients.

A prospective, randomized, placebo-controlled clinical trial was conducted in 6 clinical centers from August 1993 to December 1995.

A total of 468 participants were studied, including 125 with diabetes, who had diagnosed peripheral arterial disease.

Participants were randomly assigned to receive niacin - 3000 mg/d or maximum tolerated dosage or placebo for up to 60 weeks.

Researchers measured cholesterol, glucose, hemoglobin A1c (HbA1c), alanine aminotransferase, and uric acid levels, in addition to monitoring hypoglycemic drug use; compliance; and adverse events.

Niacin use had similar effects on lipid parameters in patients with and without diabetes such as:

• Increased HDL cholesterol by 29% in both groups

• Decreased triglycerides by 23% and 28%

• Decreased LDL cholesterol by 8% and 9%

However, glucose levels were modestly increased by niacin by 8.7 and 6.3 mg/dL in participants with and without diabetes, respectively.

Levels of HbA1c were unchanged by niacin use in participants with diabetes.

The authors state that "Our study suggests that lipid-modifying dosages of niacin can be safely used in patients with diabetes and that niacin therapy may be considered as an alternative to statin drugs or fibrates for patients with diabetes in whom these agents are not tolerated or fail to sufficiently correct hypertriglyceridemia or low HDL-C levels."

JAMA 2000;284:1263-1270

Dr. Mercola's Comments:

It is my experience that Niacin is not required for the vast majority of people with high cholesterol levels. The diet I recommend seems to work quite nicely for most nearly all people. For those that don't respond, it would seem that niacin would be a far less expensive and safer alternative to the statin drugs, which have their serious complications. There are several precautions that one needs to implement though when using niacin. Niacin usually has a flush associated with it that is very similar to the hot flashes women get during menopause. Many long-acting versions have been made available to avoid this side effect. The problem with most timed-release niacin is that they are associated with a high degree of hepatitis. I used to use large amounts of niacin about 15 years ago for patients before I knew about the diet changes and I saw quite a few people develop hepatitis from the niacin. Proving once again that the diet is far safer than even natural therapies like vitamins. There is a sustained release version of niacin called inositol hexaniacinate, which does not seem to be associated with the flushing or the hepatitis. However, concerning the conclusions of this study, I find it a little odd that, despite the fact that fasting glucose levels rose by 8.7 mg/dL in diabetics and 6.3 mg/dL in non-diabetic patients, the authors still claim that large "doses of niacin can be safely used" in diabetics. These results do seem to indicate an adverse effect on glucose tolerance. Meat is one of the best sources of niacin. Although it is present in some grains, it is often in a bound and unavailable form, such as is the case of corn. Cultures with corn-based diets are well known to be at a much higher risk of a serious form of niacin deficiency known as Pellagra. As a matter of fact, a previous newsletter article discussed the fact that some scientists now believe that many of the Native-American tribes in what is now Florida, actually died of malnutrition due to their almost exclusively corn-based diets which developed followed the settlement by the Spanish. Lastly, the human body can manufacture niacin from the essential amino acid tryptophan, so a deficiency of this can also cause a niacin deficiency. Related Article: MACULAR EDEMA ASSOCIATED WITH (NIACIN)