NAD+ has gotten a lot of hype for its potential to lower inflammation, improve cognitive function, lower the risk of type 2 diabetes and blood pressure issues, and repair the skin.
“There’s a lot of interest and promise in boosting NAD+ because of the research that’s been done in animal models, but the human research hasn’t been as exciting,” Craighead says. “A lot of the studies done with people have been small and for a short duration, and we’re still waiting for bigger studies to come out and provide definitive proof.”
Research involves NAD+ precursors (or molecules the body uses to make NAD+), mainly nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN), because NAD+ isn’t absorbed very well by the body. NR and NMN, which are smaller and more easily absorbed, are converted into NAD+ within the cells, Craighead says.
Here are some of the potential health benefits of NAD+ according to research on oral NAD+ precursor supplementation so far.
May Reduce Inflammation
One review theorized that boosting NAD+ levels reduces inflammatory markers (substances in the blood that rise due to inflammation), specifically interleukin-13 (IL-13). IL-13 plays a key role in regulating allergic responses and is associated with Parkinson’s disease and cancer.
“Reductions in inflammation is the most consistent benefit we see across studies of NR,” Craighead says. But whether the reduction in inflammation linked to NAD+ is also associated with lower chronic disease risk or prognosis hasn’t been proven, Craighead says. “What it does in the long run, we don’t yet know.”
May Improve Cognitive Function for Certain Populations
Researchers suspect the anti-inflammatory effects of NAD+ may offer perks for brain health — in particular, for inflammatory neurodegenerative diseases like Parkinson’s, Alzheimer’s, and amyotrophic lateral sclerosis (ALS). And they’ve started to investigate if there is indeed a link.
In one small study, 15 people with early Parkinson’s disease were given 1,000 milligrams (mg) of NR for 30 days. This resulted in an average increase in NAD+ levels in their brains and a decrease in inflammatory cytokines (a type of protein) compared with the 15 adults with early Parkinson’s disease in the control group.
The researchers believe NR may help prevent Parkinson’s disease from worsening, but more research is needed. “There are some promising signs of benefit, but the benefits are pretty small and only tested in a handful of people,” Craighead says.
And in research so far, NAD+ has not conclusively been shown to boost cognitive health or have protective effects for healthy individuals.
May Lower Diabetes Risk
NAD+ may lower the risk of type 2 diabetes by improving insulin sensitivity (how well your body responds to insulin, a hormone that regulates blood sugar).
For example, one study found that insulin sensitivity improved when women with prediabetes (a condition where blood sugar is higher than healthy but not high enough for diabetes) who were overweight or had obesity supplemented with NMN for 10 weeks.
NAD+ may work by reducing inflammation and oxidative stress (an imbalance between damaging substances known as free radicals and the antioxidants that neutralize them), and by increasing energy flow and autophagy (a process where the cell gets rid of unneeded or damaged components).
Craighead says the research is promising but calls for more studies with larger sample sizes.
May Improve Heart Health
NAD+ deficiency is associated with heart disease risk factors, such as obesity, aging, and high blood pressure (hypertension), leading researchers to explore whether boosting NAD+ levels can lower the risk of heart disease.
Research suggests it might. A meta-analysis of 29 studies showed that supplementing with NAD+ precursors led to a significant reduction in blood pressure and inflammation in healthy people and those with various health conditions, including high cholesterol, heart disease, and metabolic syndrome (a group of conditions that occur simultaneously and increase the risk of heart disease, stroke, and type 2 diabetes). These findings led researchers to conclude that NAD+ precursor supplementation may, through these mechanisms, lower the risk of cardiovascular disease.
Craighead notes that a caveat of this review is that it involved studies using niacin, which is a precursor to NAD+, but isn’t commonly used, owing to its adverse side effects.
