Can boosting NAD+ really slow ageing - or is it all hype? Photo / DepositPhotos
Infusions and pills are easy to come by. But there’s a lot that scientists don’t yet know.
The cells in our bodies naturally break down as we age, making it harder to bounce back from illness and injury in our later years. What if you could make your cells more resilient to damage to stave off that decline?
That’s the idea behind NAD+ boosting, a trendy longevity therapy.
Nicotinamide adenine dinucleotide, or NAD+, is a molecule found in all cells that’s essential for repairing damage, generating energy and encouraging healing. NAD+ levels decrease with age, and some scientists think that increasing those levels through infusions or supplements could potentially slow the ageing process. But they warn that the treatments are unregulated and largely unproven.
Research on mice strongly supports using some NAD+ boosting therapies for healthy ageing, said Daniel Craighead, an assistant professor of exercise physiology at the University of Minnesota who has studied NAD+. But scientists don’t know whether the therapies on the market meaningfully improve healthspan or lifespan in humans, he said.
“The literature is very scarce” on healthspan and lifespan, echoed Jonas Thue Treebak, an associate professor at the University of Copenhagen’s Novo Nordisk Foundation Center for Basic Metabolic Research in Denmark. “The science is almost nonexistent.”
That hasn’t stopped people – including longevity expert-influencers like David Sinclair and celebrities like Joe Rogan – from trying the treatments.
NAD+ levels below a certain threshold are correlated with a higher risk of organ and tissue dysfunction, said Dr Shin-ichiro Imai, a professor of environmental medicine at Washington University School of Medicine in St. Louis. (Many experts who study NAD+ also have associated financial ties. For example, Imai receives royalties on patents for some products related to NAD+.)
But scientists are still debating whether NAD+ decline actually speeds the ageing process or if it’s just associated with it.
“I don’t think you can say there is or there isn’t evidence that NAD+ drives the ageing process,” said Dr Eduardo Chini, a pharmacology professor who runs a metabolic research lab at the Mayo Clinic in Jacksonville, Florida. (Chini has a patent on a drug that blocks a protein believed to break down NAD+ but said he did not support the use of these types of inhibitors or therapies until large-scale clinical trials had proven their benefits.)
Along with trying to better understand the role of the molecule in ageing, researchers are investigating the best way to increase its levels in the body.
NAD+ boosting is an umbrella term for several longevity therapies on the market. These include NAD+ infusions or pills, as well as treatments using smaller molecules, called “precursors,” that convert into NAD+ once they’re in the body. These include nicotinamide mononucleotide, or NMN, and nicotinamide riboside, known as NR.
Many experts think the NAD+ molecule is too big to be absorbed into cells and that the precursors have more potential promise for anti-ageing.
Early evidence on NAD+ boosting in mice (including a study that Imai worked on) has shown that rodents that were given NMN treatments lived longer and stayed healthier than those who did not receive the treatments, though some trials suggest the effects could vary by sex.
The human studies have been very small, and the results have been modest. One analysis of studies that focused on NMN therapy for improving metabolic health concluded that infusions and oral supplements had little to no benefit. Another set of studies using a variety of precursors found mild improvements in cell function and reduced inflammation.
Small studies specifically focused on NAD+ boosting in older adults, and in people with particular health conditions, have shown more benefits. A 12-week study on 60 subjects found that NMN mildly improved the sleep quality of healthy adults in their 70s and 80s. Another on two dozen prediabetic women found that NMN improved insulin sensitivity, but the researchers only observed subjects over 10 weeks.
“In humans, no studies have been conducted to show that elevating NAD+ levels in young age can prevent the loss of NAD+ as we age,” Treebak said.
Longevity clinics offer weekly or biweekly IV infusions for hundreds of dollars a session, and retailers sell pills, to be taken daily or weekly, starting at about US$20 a month. Some use NAD+ itself, while others use precursors or other versions of the molecule.
Because these treatments are marketed as wellness products or dietary supplements, they don’t have to be reviewed or approved by the Food and Drug Administration before they are sold to consumers. As a result, the manufacturers’ claims may not be supported by scientific evidence, said Jennifer Oliva, a professor at the Maurer School of Law at Indiana University Bloomington.
There can also be a wide variation in the products’ dosage and quality. One recent study found that most NMN supplements contain a different amount of the molecule than advertised. In an email to The New York Times, an FDA spokesperson said the agency had not approved any NAD+ products for medical use and that it had sent warning letters to companies marketing NAD+ products with unproven health claims.
If you decide to try NAD+ boosting, experts recommend caution. While short-term human studies suggest these therapies may be safe, “we don’t know what the long-term effects of these supplements may be,” Craighead said.
It’s also not clear if taking an excess amount of any of these supplements could damage organs, including the liver, said Joseph Baur, a physiology professor at the University of Pennsylvania Perelman School of Medicine. And studies have noted some potential side effects, including headaches and muscle pain.
It’s also possible that these treatments could be more effective for a different set of patients. Some researchers think there’s stronger evidence that NAD+ therapies slow the progression of age-related illnesses, like heart disease or Parkinson’s disease, rather than delay cell ageing in young, healthy people, Baur said. (Baur has consulted for and received research funding from companies studying NAD+, and he has a patent related to the molecule.)
Baur also thinks NAD+ may be better used to battle illness than to slow cell ageing. He also worries that commercialising its use in unproven longevity treatments could take the focus away from studying its potential to treat diseases like Parkinson’s.
Too much hype could “hurt real therapies,” he said.
This article originally appeared in The New York Times.
Written by: Mohana Ravindranath
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