A new path to reversing Alzheimer’s: Restore brain energy

For decades, Alzheimer’s disease has been approached as something that might be prevented, delayed or slowed — but not reversed.

Research from Case Western Reserve University challenges that assumption.

Scientists found a way to restore a vital cellular process in brains already showing advanced Alzheimer’s-like damage.

What happened next got researchers’ attention…

A blood biomarker used to track Alzheimer’s disease moved back toward normal.

The findings point to an intriguing possibility:

Alzheimer’s may involve more than plaques and tangles. It may also involve a breakdown in the way aging brain cells produce energy, handle stress and repair themselves.

And if researchers can restore that machinery, damaged brains may have more capacity to recover than anyone expected.

There is an important limitation: the dramatic recovery occurred in animal models, not people.

But researchers also found evidence of the same underlying cellular disruption in human Alzheimer’s brain tissue.

So what exactly did they restore?

Quick answer: What did researchers discover?

NAD+, short for nicotinamide adenine dinucleotide, is found in every cell in your body.

Your mitochondria — the tiny structures that generate much of the energy your cells need — rely heavily on it.

But NAD+ does much more than help make energy. It also plays important roles in DNA repair, cellular stress responses and other processes that help cells function and survive damage.

The Case Western researchers found that normal NAD+ balance was more severely disrupted in the brains of people with Alzheimer’s.

They found the same problem in two very different mouse models of Alzheimer’s — one driven primarily by amyloid abnormalities and another by abnormal tau.

Then they asked a much bigger question:

What would happen if they restored that balance after the disease was already advanced?

The damaged brain began repairing itself

The researchers used an experimental compound called P7C3-A20.

Importantly, it wasn’t simply designed to flood the brain with NAD+.

Instead, it helped stressed brain cells maintain NAD+ homeostasis — keeping this critical molecule within the range cells need to function properly.

After treatment, researchers saw improvements in an extraordinary list of Alzheimer’s-related problems.

Tau phosphorylation decreased.

Oxidative stress and DNA damage improved.

Neuroinflammation decreased.

Damage to the blood-brain barrier was reversed.

The birth of new neurons in the hippocampus improved, as did synaptic plasticity — the brain’s ability to strengthen and reorganize connections between neurons.

And perhaps most strikingly, mice with advanced cognitive impairment fully recovered their cognitive function.

Blood levels of p-tau217 — a biomarker now used clinically to help identify Alzheimer’s pathology in people — also normalized.

Senior researcher Dr. Andrew Pieper said the results suggest the effects of Alzheimer’s may not necessarily be permanently fixed.

Under the right conditions, he explained, a damaged brain may retain an ability to repair itself and regain function.

That may be the most exciting part of this research.

Alzheimer’s and the brain’s energy problem

Your brain is an energy-hungry organ.

Neurons need tremendous amounts of energy to transmit signals, maintain their electrical balance, repair damage and communicate with neighboring cells.

Much of that energy comes from mitochondria.

And NAD+ is woven throughout mitochondrial energy production.

Research increasingly connects disturbed NAD+ metabolism with mitochondrial dysfunction, impaired cellular repair and several processes involved in aging and neurodegenerative disease.

That makes these findings particularly interesting for healthy aging.

They suggest the question may not simply be:

How do we remove amyloid or abnormal tau?

Another question could be:

Can an aging brain still repair itself if we restore the cellular machinery it needs to produce energy and respond to damage?

In these mice, at least, the answer was remarkably encouraging.

NAD+ and aging

This story becomes even more interesting when you consider what happens to NAD+ as we age.

NAD+ metabolism changes over time, and research suggests NAD+ availability generally declines with age.

That matters far beyond Alzheimer’s.

NAD+ supports mitochondrial function, DNA repair and cellular responses to metabolic and oxidative stress — processes involved in how virtually every tissue in the body ages.

That’s one reason NAD+ has become such a major focus of longevity research.

It has also fueled interest in supplements designed to support NAD+, particularly the precursors nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN).

A 2026 systematic review examining 113 human and rodent studies found that increasing NAD+ was frequently associated with improvements in metabolic, mitochondrial, inflammatory and functional measures in animal studies.

Human results have been less clear.

NR and NMN consistently affected NAD-related biomarkers and were generally well tolerated during the periods studied. But measurable improvements in metabolic, vascular and other health outcomes were inconsistent.

In other words, we know these compounds can influence NAD metabolism.

We do not yet know that taking them can prevent — much less reverse — Alzheimer’s disease.

More NAD+ isn’t necessarily better

There’s another important wrinkle.

The Case Western researchers specifically caution against assuming that if restoring normal NAD+ balance is beneficial, pushing NAD+ higher and higher must be even better.

That isn’t what their experimental treatment did.

P7C3-A20 helped cells maintain normal NAD+ homeostasis under severe stress rather than driving NAD+ to unusually high levels.

The researchers also raised concerns that excessive increases in NAD+ from some precursor approaches have promoted cancer in animal models.

That doesn’t mean ordinary use of an NAD+ precursor supplement causes cancer in people.

But it does underscore an important distinction:

The goal may be healthy NAD+ balance, not simply as much NAD+ as possible.

Supporting the machinery that powers your cells

There is currently no supplement shown to reproduce what P7C3-A20 accomplished in these mice.

But that doesn’t mean we have to wait for a future Alzheimer’s drug to think about the health of our mitochondria and cellular energy systems.

Exercise is one of the best-established ways to support mitochondrial health and stimulate the body to maintain and produce healthy mitochondria.

Good metabolic health matters, too. Chronically elevated blood sugar and metabolic dysfunction can increase oxidative stress and place greater demands on cellular energy systems.

Your body also needs adequate vitamin B3 because it uses B3 compounds as building blocks for NAD+.

NR and NMN represent another intriguing avenue. They are specifically designed to provide the body with precursors it can use to make NAD+, and research into their potential benefits for healthy aging continues.

But right now, the strongest message from this particular Alzheimer’s study isn’t that everyone should take an NAD+ supplement.

It’s something potentially much bigger.

For years, we have largely thought about Alzheimer’s damage as something that, once established, could only be slowed.

These researchers restored a fundamental part of cellular energy metabolism — and severely damaged brains began functioning again.

Of course, what happens in mice must now be translated to people.

But the findings raise an encouraging possibility:

An aging brain may have far more capacity for repair than we’ve assumed.

And protecting the cellular machinery that gives it the energy to do that may be an important piece of the healthy-aging puzzle.

Sources:

New study shows Alzheimer’s disease can be reversed to achieve full neurological recovery—not just prevented or slowed—in animal models — Case Western Reserve University

Pharmacologic reversal of advanced Alzheimer’s disease in mice and identification of potential therapeutic nodes in human brain — Cell Reports Medicine

NAD+ supplementation for anti-aging and wellness: A PRISMA-guided systematic review of preclinical and clinical evidence — Ageing Research Reviews

FAQ: What to know about NAD+, brain energy and Alzheimer’s