A new study is raising one of the most hopeful questions in Alzheimer’s research in decades: what if the disease is not always a one way road?
Researchers found that restoring balance to a key cellular molecule called NAD+ prevented Alzheimer’s-like disease in mice and, even more striking, reversed major signs of advanced disease in animal models that were already badly impaired. The results were dramatic enough to challenge one of the oldest assumptions in brain science, that Alzheimer’s is essentially irreversible once it takes hold.
Credit is also due to Anti-aging commentator Nils Osmar and his Facebook group, Stop Aging Now, for helping bring attention to the study while also stressing the need for caution. Nils described it as “a promising study, but not proof of efficacy in humans yet,” which is a fair summary of where things stand.
The study was led by Andrew A. Pieper and a large team of collaborators working with human brain samples, mouse models, and cell culture systems. Pieper is affiliated with Case Western Reserve University and University Hospitals, and the paper states that he is also a cofounder of Glengary Brain Health, Inc.
That matters because the paper also discloses that Pieper and several coauthors “hold related patents.” Nils Osmar highlighted this conflict issue, noting that the lead researchers have a financial stake connected to the compound used in the study. That does not invalidate the work, but it does mean the findings should be viewed with careful scrutiny and confirmed by outside groups.
What Is NAD+
NAD+ stands for nicotinamide adenine dinucleotide. It is a molecule found in all living cells and plays a central role in energy production and cellular repair.
In this study, the researchers describe NAD+ homeostasis, meaning the brain’s ability to maintain healthy NAD+ balance, as a core part of brain resilience. When that balance breaks down, cells struggle to handle oxidative stress, DNA damage, inflammation, blood-brain barrier breakdown, and other problems tied to Alzheimer’s.
The researchers found that in both human Alzheimer’s brain samples and mouse models of Alzheimer’s, NAD+ balance was significantly disrupted. In human Alzheimer’s brains, they found about a 30 percent reduction in the NAD+/NADH ratio. In 5xFAD mice, the decline was about 30 percent by 6 months and 45 percent by 12 months.
That made NAD+ look less like a side issue and more like a central part of the disease process.
How The Study Was Conducted
The research was extensive and used several layers of testing.
The team worked with two major mouse models of Alzheimer’s. One model, called 5xFAD, is driven by amyloid pathology and develops many Alzheimer’s-like changes, including plaque buildup, tau phosphorylation, inflammation, synaptic damage, blood-brain barrier deterioration, and cognitive decline. The second model, called PS19, is driven by abnormal tau.
The researchers tested the compound P7C3-A20 in two different windows.
In the prevention group, mice were treated from 2 to 6 months of age, before full disease had taken hold.
In the reversal group, mice were treated from 6 to 12 months of age, when disease was already advanced and cognitive deficits were established.
The mice received daily intraperitoneal injections of P7C3-A20 at 10 mg per kilogram. The researchers then ran behavioral tests, brain tissue analysis, blood biomarker tests, microscopy, protein studies, and cell experiments using human brain microvascular endothelial cells.
They also looked at postmortem human Alzheimer’s brain tissue to see whether the same NAD+ disruption seen in mice was also present in people.
How NAD+ Was Increased In The Study
This is one of the most important details.
The researchers did not use common NAD+ boosters like NR, NMN, niacin, or direct NAD+ itself. Instead, they used P7C3-A20, which the paper describes as “a neuroprotective compound that restores NAD homeostasis without raising NAD to supraphysiologic levels.”
In simple terms, they used an experimental small molecule designed to help the brain restore normal NAD+ balance, not to flood the system with unusually high levels.
The paper says the effect depended on the NAD salvage pathway and was blocked by FK866, a NAMPT inhibitor. That suggests P7C3-A20 was working through the cell’s internal NAD recovery system rather than by simply adding NAD+ from the outside.
What The Study Found
The results were remarkable in mice.
The researchers reported that preserving NAD+ balance protected mice from developing Alzheimer’s-like disease. Even more surprising, when treatment began after major disease had already developed, the animals still showed major recovery.
According to the paper, restoring NAD+ homeostasis reversed tau phosphorylation, blood-brain barrier deterioration, oxidative stress, DNA damage, neuroinflammation, and several markers of synaptic failure. It also improved hippocampal neurogenesis and synaptic plasticity.
Most importantly, the mice recovered cognitive function. The paper states that “both lines of mice fully recovered cognitive function.”
In the 5xFAD mice, treatment improved performance in novel object recognition and the Morris water maze, two classic tests of memory and learning. In the PS19 tau model, animals treated at a near terminal stage showed improved cognitive performance within 15 to 30 days.
The study also found that blood levels of phosphorylated tau 217, an important Alzheimer’s biomarker used in people, were normalized in the treated mice. That gave the researchers an objective marker that matched the behavioral recovery.
Why This Study Is Getting So Much Attention
The real significance of the paper is not just that the mice improved. It is that the researchers are directly challenging the old idea that Alzheimer’s can only be slowed, never meaningfully reversed.
In the discussion section, the authors write that their findings “challenge the long-held view that AD is intrinsically irreversible.” They argue that restoring NAD+ homeostasis may rebuild the brain’s resilience rather than merely attacking one downstream target like amyloid.
That is a big shift. Instead of focusing only on clearing plaques or reducing symptoms, this approach suggests the brain may regain function if core metabolic balance can be restored.
Nils Osmar’s contribution is important because he draws a sharp line between what the study showed and what it did not show.
He points out that the researchers did not prove that P7C3-A20 is better than more common NAD+ boosting methods. As he put it, there is “no proof that their injected compound is superior to other ways of raising NAD+ if it should be true.”
He specifically mentions NAD+ precursors such as NR, NMN, and niacin as other possible ways to raise NAD+ levels. His argument is that if the study’s central insight is correct, namely that restoring NAD+ balance helps the brain resist or reverse Alzheimer’s pathology, then more accessible NAD+ boosters might also prove useful.
He also criticized the paper’s warning that NAD+ precursors “may also produce supraphysiologic NAD+ levels that promote cancer.” Nils called that claim “disingenuous,” arguing that if high NAD+ truly fueled cancer, then an injected compound that raises NAD+ related pathways could also face similar questions. He further noted that there is no proof from the material provided that NAD+ boosters are causing higher cancer rates in the real world.
Why More Common NAD+ Boosters Would Be Easier
This is where the study becomes especially interesting for the public.
The compound used in the research required daily injections into mice. That is a major barrier for routine use in real people, especially over long periods. By contrast, NR, NMN, and niacin are already known as NAD+ precursors and are much easier to take.
Nils argues that these methods would be easier and more common because they are simpler to administer and already widely used by many people trying to support metabolism and healthy aging. If future studies show that boosting NAD+ through these more familiar routes can produce similar brain effects, that would be far more practical than daily injections of an experimental drug.
But that is still an open question. This study did not test those alternatives.
What Are People Saying About This
The strongest voices in the material fall into two camps.
The researchers are highly optimistic. They say their findings provide “proof of principle for therapeutic reversibility of advanced AD” in preclinical models. They believe therapies aimed at restoring brain resilience through NAD+ normalization “merit clinical evaluation for prevention and reversal of AD and related dementias.”
Nils Osmar is hopeful but cautious. He repeatedly stresses that this was not a human trial and that human studies are now needed. He sees the study as promising, but he does not accept it as proof that this exact compound is the answer.
That may be the most sensible position of all. The results are exciting enough to deserve attention, but not strong enough to justify hype.
What This Means For The Outlook On Alzheimer’s Reversal
The outlook is more hopeful than it was before this study, but it is still early.
The study does something very important. It opens the door wider to the idea that Alzheimer’s may be biologically modifiable in deeper ways than many experts assumed. It suggests that the disease may involve a loss of brain resilience that could potentially be restored.
That is not a cure. But it is more than a small step.
