Oh, yes, there is a right way to take high-dose immediate release niacin. Take it at the right time and you can get a host of health benefits, especially reduced triglycerides, LDL, and VLDL and increased HDL—at the wrong time, you lose some of these benefits. Here’s why.
Niacin causes cellular metabolism to switch from primarily using glucose as a fuel to primarily using fats, except in the heart, where lipids are the primary fuel and niacin causes a switch to glucose (Carlson, 2005). This switch takes place postprandially, that is, right after you eat, which is when you experience the highest level of blood fats, high enough to increase the risk of a heart attack. That is why some people have a heart attack after eating a heavy meal.
The process of being able to switch between using metabolic substrates is termed metabolic flexibility ... (Virtue, 2012).
After eating, fats are taken up and stored by adipose tissue, which releases fatty acids (a process called lipolysis) to the liver and to muscles. “During the fed state, net lipid flux into adipose tissue increases, whereas in the fasted state net lipid efflux predominates” (Virtue, 2012). Niacin prevents lipolysis, the release of these fatty acids from adipose tissue into the bloodstream. (The liver uses the fatty acids to produce triglycerides. The reduction in the availability of free fatty acids for the liver to make triglycerides is why niacin causes a reduction in triglycerides (Virtue, 2012; Kroon, 2017).
There is a strong negative correlation between plasma triglyceride levels and the concentration of HDL—as the level of triglycerides go up, HDL levels go down. The major components of VLDL (very low density lipoproteins) are triglycerides derived from the liver; the VLDL then carry triglycerides in the bloodstream. Reduction of the synthesis of triglycerides in the liver by niacin importantly increases HDL and reduces VLDL.
During the periods when you haven’t eaten (or at night when you sleep), your cells primarily use fats as primary fuel. Taking niacin can’t “switch” the choice of metabolic fuel to fats when you are already using fats as a fuel, but it can reduce the ability of cells to use glucose, which is why some people have a small increase in blood glucose when they use niacin. “We suggest that postprandial FFA [free fatty acid] lowering is the primary mechanism driving the metabolic improvements resulting from NiAc [nicotinic acid, niacin] timed to feeding. Reduced FFA supply to the tissues lowers substrate competition with glucose and improves insulin sensitivity just when it is needed the most (i.e., during the influx of dietary carbohydrate in the postprandial phase), resulting in reduced postprandial hyperglycemia and hyperinsulinemia (Kroon, 2017).”
Thus, the best way to use niacin as a supplement is to take it during or just after a meal, not at other times.
This, incidentally, is one reason why we do not recommend using extended-release niacin: it does not limit niacin to the times when it is best to take it, during or just after a meal.
THE EFFECTS OF EMOTIONAL STRESS REDUCED BY NIACIN
Another potential benefit from taking niacin is that niacin has been shown in healthy human subjects to reduce the elevated fatty acids and triglycerides that resulted from 2 hours of emotional stress as compared to similar human subjects receiving the same emotional stress but no niacin. (Carlson, 2005, p. 99)
Carlson. Nicotinic acid: the broad-spectrum lipid drug. A 50th anniversary review. J Int Med. 258:94-114 (2005).
Kroon et al. Nicotinic acid timed to feeding reverses tissue lipid accumulation and improves glucose control in obese Zucker rats. J Lipid Res. 58:31-41 (2017).
Virtue et al, A new role for lipocalin prostaglandin D synthase in the regulation of brown adipose tissue substrate utilization. Diabetes. 61:3139-47 (2012).