Tons of studies pointing to this in healthy individuals. Is niacinamide really safe to consume long term?
Any link? This same B3 is found in a lot of leafy greens, so it seems unlikely to me that it really is a dangerous chemical.
I’m talking about nicotinamide aka niacinamide. Yes it is the same B3 found in food, but nobody gets 500mg per day from food alone. Supplementing with this vitamin may be dangerous and I am trying to assess the risks. Right now there seems to be conflicting studies. Keep in mind, this is not the same thing as niacin. Many people take this supplement at 500mg to 1g per day. I myself take about 500mg every now and then because it gives me energy. I am posting some studies below, but if anybody wants to go deeper down this rabbit hole, feel free to google.
Studies that Claim Niacinamide Causes Insulin Resistance:
Studies that Claim No Change in Insulin Sensitivity from Niacinamide:
Sure, OK. The top study gave 2000mg/day of nicotinamide to study participants, compared to the 16mg present in 2000kcal of Soylent. The bottom gave 25mg/kg per day, so a 110 pound person (~50kg) would be taking 1250mg/day, a 220 pound person would be taking 2500mg/day. It’s no secret that huge doses of some vitamins can be harmful. Until there’s a study showing that something close to 16mg/day is harmful, it’s not something I’m going to worry about.
There are some incorrect assumptions here. The big assumption is that each vitamin is derived from exactly one chemical compound. I happen to have studied niacin a while back, for something unrelated, and nicotinamide is not the only compound we can get niacin from.
Niacin can be derived from at least, nicotinamide and nicotinic acid. Most modern supplements use nicotinamide, because it is not a vasodilator. Nicotinic acid supplements are known for causing the face and other skin to turn red, because in large quantities, it opens up blood vessels, especially surface capillaries. This effect is typically considered undesirable (I was researching as a treatment for poor surface blood circulation, where it was desirable), so most companies make their supplements with nicotinamide instead (often sold as “no flush niacin”).
Niacin can be obtained from consuming nicotinic acid because it is niacin. (Nicotinic adic is the chemical name for niacin.) Nicotinamide (niacinamide) is a compound that the body breaks down into niacin. Niacin from plants is nicotinic acid. Niacin can also be synthesized by the body from tryptophan, which is found in many protein containing foods. (These studies don’t seem to have considered it in this context.) To my knowledge, nicotinamide is not found in any natural food product.
So, nicotinamide is not found in a lot of leafy greens or any other natural foods. Niacin, aka nicotinic acid, is, and tryptophan, which is metabolized into niacin, is. This means that nicotinamide might be a dangerous chemical! The real question is: What are the byproducts of nicotinamide being metabolized into niacin, and are those byproducts dangerous? Because if there is anything dangerous about nicotinamide, that is probably where it would be.
(I should note that there are other compounds that the body breaks down into niacin as well, including inositol nicotinate. I know next to nothing about these, because they were not relevant to my research.)
Also keep in mind though, that there is plenty of evidence that consuming vitamins and minerals in purified forms is more likely to have side effects than consuming them in natural foods*. There is evidence that interactions between specific nutrients with other compounds found in foods (that are not found in supplements) can reduce or even eliminate negative side effects. So while these studies all suggest that nicotinic acid has the same negative effects as nicotinamide with relation to insulin response, it is not clear that niacin consumed in plant sources would have the same effect. (The niacin studies these reference probably also administered it in a purified form, making a reliable conclusion on the effect of consumption in plant form impossible.) Likewise, the amounts do make a difference. Most vitamins are straight up poisonous taken in sufficiently large amounts. That does not mean consuming them as part of a regular diet is going to kill you.
(*For clarification, when I say “natural foods”, I do not mean non-GMO or organic. I mean, foods that are grown or otherwise derived from nature, regardless of cultivation methods or pre-processing modifications. This definition does not include foods processed into pure compounds or mixtures where significant elements are removed. For example, table sugar, cane sugar, and corn syrup are all non-natural by this definition, because the fiber and other elements of the plants they are derived from have been removed.)
Do you have a link to specific article?
nicotinamide paired with riboside (e.g., the branded form Niagen) acts differently than niacinamide by itself.