In what researchers are calling an important scientific advance, a team in the US has shown through animal experiments that Alzheimer’s disease may be reversible, overturning a belief that has shaped medical thinking for more than 100 years. For generations, the neurodegenerative condition was considered permanent and progressive. The findings, published in Cell Reports Medicine, are based on multiple preclinical mouse models as well as examinations of human Alzheimer’s brain tissue.The study found that preserving a healthy balance of NAD, a molecule central to cellular energy production, could both prevent and reverse Alzheimer’s-related damage. NAD plays a key role in brain function and is now seen as a major contributor to the disease process. Researchers also observed that NAD levels drop much more sharply in the brains of people with Alzheimer’s, a pattern that was mirrored in mouse models of the condition.Don't Miss: Taking Tramadol? Scientists Warn It May Cause More Harm Than ReliefAlzheimer’s Disease Can Be Reversed, New Study Shows“We were extremely encouraged by what we observed,” said Andrew A. Pieper, the study’s senior author and Director of the Brain Health Medicines Center at the Harrington Discovery Institute, University Hospitals, as per Sciencedirect. “By restoring the brain’s energy balance, we saw both structural and functional recovery in mice with advanced Alzheimer’s.”Pieper noted that the effect appeared consistently across two very different mouse models, each driven by separate genetic mechanisms linked to Alzheimer’s in humans. “Seeing recovery in models caused by distinct genetic pathways strengthens the case that restoring NAD balance in the brain could have real therapeutic potential for patients,” he said.For the study, researchers examined mice engineered to carry genetic mutations known to cause Alzheimer’s disease in people. One group of mice carried multiple human mutations affecting amyloid processing, while the second group carried a human mutation in the tau protein.After confirming that brain NAD levels dropped sharply in both human Alzheimer’s tissue and mouse models, the team tested whether stopping this decline before symptoms appeared could prevent disease, and whether restoring NAD levels after the disease had progressed could reverse it. To do this, they used a well-studied drug called P7C3-A20 to restore NAD balance in the brain.The results were striking. Not only did maintaining NAD levels prevent Alzheimer’s from developing in mice, but starting treatment later, after the disease was already advanced, allowed the brain to repair the main pathological damage caused by the genetic mutations. In both mouse models, cognitive abilities were fully restored.What Is NAD In Alzheimer’s?In Alzheimer’s disease, NAD, short for nicotinamide adenine dinucleotide, is an essential coenzyme whose levels naturally decline with age. This decline disrupts energy production, mitochondrial health, DNA repair, and the ability of neurons to withstand stress. Research suggests that increasing NAD levels, often through precursors such as nicotinamide riboside, may reverse Alzheimer’s-related damage, improve memory, and correct abnormal RNA processing in animal models. Because of this, NAD has become a major area of focus for developing new Alzheimer’s therapies, according to the National Institutes of Health.Why NAD Is Important In Alzheimer’sEnergy and Mitochondria: NAD is necessary for producing ATP, the cell’s main energy source, and for keeping mitochondria functioning properly, both of which are critical for healthy brain cells.Cellular Stress: NAD supports neurons in responding to and surviving stress. When NAD levels fall in Alzheimer’s, these protective mechanisms weaken.DNA Repair: NAD is involved in repairing DNA damage, which increases as amyloid-beta accumulates in the brain. Low NAD levels interfere with this repair process.RNA Splicing: Emerging research shows that NAD may help correct faulty RNA splicing events linked to Alzheimer’s. This process may involve a protein called EVA1C and could contribute to improved memory and better clearance of harmful proteins.Next Steps Toward Human TrialsThe findings also pave the way for further research and eventual testing in people. The technology behind the treatment is currently being developed for commercial use by Glengary Brain Health, a Cleveland-based company co-founded by Dr. Pieper.“This recovery-based treatment approach now needs to be tested in carefully designed clinical trials to see if the benefits seen in animals can be replicated in humans,” Pieper said.He added that future laboratory work will focus on identifying which components of brain energy balance matter most for recovery, exploring additional strategies that could complement this approach, and determining whether similar methods could work for other long-term, age-related neurodegenerative diseases as well.