Walking into a room and forgetting why you went in. Is that normal — or something more?

YOUR HEALTH — Issue No. 25

Almost every patient over 50 has had the conversation with themselves.

You walk into a room and forget why you went in. A name you have known for years won't come when you need it. You lose a word mid-sentence — it's right there, and then it isn't. You read the same paragraph twice.

And somewhere underneath that moment is a quiet question: is this the beginning of something?

It is one of the most common fears I hear in practice — and one of the most important things I can do for a patient is help them understand what is actually happening and what is not.

What normal aging actually looks like

The brain changes with age. This is not a failure — it is biology. And understanding what is expected makes it considerably easier to recognize what is not.

Processing speed slows. The brain takes slightly longer to retrieve information and execute tasks than it did at 30. This is one of the most consistent and well-documented changes in cognitive aging and it begins gradually in midlife.

Word retrieval takes longer. The name, the word, the fact — it is there, and it surfaces eventually. This is the tip-of-the-tongue experience that becomes more common with age. It is not memory loss. It is retrieval delay.

Multitasking becomes harder. The ability to manage multiple streams of information simultaneously declines with age. This is a real change — but it is normal, and it does not indicate disease.

Learning new things takes more repetition. New information requires more exposure before it consolidates into memory. This is normal aging of the memory encoding process — not dementia.

The critical point in all of these: normal cognitive aging does not interfere with daily function. You may take longer. You may need more repetition. But you can still manage your finances, your medications, your appointments, and your relationships. The word comes back. The task gets done.

That distinction — does this affect my daily function? — is the most important clinical question in this conversation.

What is not normal — and when to pay attention

Mild cognitive impairment — MCI — sits between normal aging and dementia. Memory changes exceed what is expected for age, but daily function is largely preserved. It is a clinical state worth knowing about because it is common, it is often the first recognizable sign that something is changing, and it is not inevitable dementia.

People with MCI have a substantially higher risk of developing dementia than cognitively normal adults — but many people with MCI remain stable for years, and some improve. The clinical picture matters enormously: the underlying cause, the pattern of changes, the presence of reversible contributors, and the modifiable risk factors all influence where it goes.

Warning signs worth bringing to a provider:

Getting lost in familiar places — a neighborhood walked a hundred times, a route driven for years.

Forgetting recent conversations — not what happened years ago, but what was said this morning or yesterday.

Asking the same question multiple times within a short period — without realizing it has been asked before.

Significant personality or behavior changes — withdrawal, suspicion, uncharacteristic irritability.

Difficulty managing tasks that were previously routine — medication management, paying bills, following a recipe.

Confusion about time, date, or place — not misremembering a day of the week, but genuine disorientation.

These are not senior moments. They are signals worth talking to your provider about. Not explaining away.

One more thing — sudden confusion is different.

A gradual change in memory or thinking deserves a scheduled appointment. Sudden confusion is different. If someone suddenly becomes confused or disoriented, has trouble speaking, develops weakness, or has a significant and abrupt change in behavior — seek urgent medical attention. That is a different clinical situation and it should not wait.

"Can I just take Prevagen for this?"

This is the question I want to spend a moment on — because if you have watched television in the last decade, you have seen the advertisements.

Prevagen is a supplement containing apoaequorin — a protein derived from bioluminescent jellyfish — marketed for years as a memory aid for aging adults. The commercials showed dramatic charts. The claims were specific and confident: clinically shown to improve memory, results within 90 days.

In December 2024, a federal court issued an injunction prohibiting the makers of Prevagen from claiming it improves memory or cognitive function. This was the conclusion of a lawsuit brought by the Federal Trade Commission and the New York Attorney General — litigation that began in 2017 and went to trial.

The company's own clinical study — the only published trial of the product — found no statistically significant improvement over placebo on any of the nine cognitive measures it set out to test.

Between 2007 and mid-2015, Prevagen generated approximately $165 million in US sales — according to figures cited by federal regulators in their lawsuit.

This is not an isolated story. It is an illustration of something that runs throughout the supplement conversation — marketing can run far ahead of evidence, particularly when the target audience is older adults who are quietly worried about their memory and looking for something they can do.

There is no supplement with established clinical evidence for preventing cognitive decline or dementia. That includes Prevagen, ginkgo biloba, high-dose B vitamins in patients without deficiency, and the many products currently marketed with phrases like "supports brain health." The word "supports" is doing a lot of work on those labels.

What does have evidence — genuinely compelling evidence — is a different conversation entirely.

What actually moves the needle

The 2024 Lancet Commission on dementia prevention identified 14 potentially modifiable risk factors. The Commission estimated that addressing all 14 could potentially prevent or delay up to 45% of dementia cases worldwide.

That is not a small number — and it is one of the most empowering clinical facts in this issue. Nearly half of dementia cases are potentially modifiable. This does not mean every case is preventable — it means the risk factors we can address are meaningful and worth addressing.

Here are the factors with the strongest relevance for Plain Medicine's audience:

Blood pressure — hypertension in midlife is one of the most consistently documented risk factors for dementia. The same elevated pressure that damages arteries in the heart and kidneys damages the small cerebral vessels that support brain tissue over decades. If you read Issue #23 on blood pressure — this is why that conversation matters beyond cardiovascular disease. Controlling blood pressure is one of the most evidence-supported things a person can do for long-term brain health.

Sleep — during sleep, the brain's glymphatic system — its waste clearance mechanism — clears metabolic byproducts including amyloid beta, the protein that accumulates in Alzheimer's disease. Consistently disrupted sleep impairs this clearance. Treating sleep apnea is particularly relevant — untreated sleep apnea accelerates both cardiovascular and cognitive risk.

Physical activity — regular aerobic exercise is one of the most consistently supported modifiable factors for brain health across the literature. It increases blood flow to the brain, supports neuroplasticity, reduces inflammatory markers, and has been shown to increase the volume of the hippocampus — the brain region central to memory formation. The recommendation is not elite athleticism. It is consistent moderate-intensity movement most days of the week.

Hearing loss — one of the most underappreciated risk factors on the Lancet list. Untreated hearing loss increases cognitive load — the brain expends more resources decoding sound, leaving fewer resources for memory and executive function. Social withdrawal driven by hearing difficulty compounds the effect. Randomized trials have provided encouraging evidence that treating hearing loss may slow cognitive decline, particularly in older adults at higher risk. If you have been told you have hearing loss and have not addressed it — this is worth taking seriously beyond the obvious quality of life reasons.

Social connection — a 2024 meta-analysis of more than 600,000 participants across 21 longitudinal studies found that loneliness increases dementia risk by 31%. Social connection is not simply a quality-of-life issue. It is associated with cognitive health and is now recognized as a modifiable dementia risk factor on the Lancet Commission list. For Plain Medicine's audience — retirement, loss of a spouse, children moving away — the structural pressures on social connection in the over-50 population are real. Maintaining meaningful engagement matters.

Vision loss — newly added to the 2024 Lancet Commission list. Untreated vision loss reduces sensory input and engagement with the world in ways that appear to accelerate cognitive decline. Treating correctable vision problems — cataracts, refractive error — is a meaningful and accessible intervention.

Cholesterol — also newly added in 2024. High LDL cholesterol in midlife is now recognized as a modifiable dementia risk factor based on large cohort studies. The cardiovascular and cognitive risk reduction arguments for managing LDL are now pointing in the same direction.

Something worth saying plainly:

The supplement industry has spent years selling hope to people who are afraid of losing their minds. The fear is understandable. But there is no supplement with established evidence for preventing dementia. The things that have the strongest evidence are much less marketable.

Blood pressure control. Exercise. Sleep. Hearing. Vision. Connection. Cholesterol.

The brain is not separate from the body. What protects the heart protects the brain. Plain Medicine has been covering these topics all year — because they are connected. The same underlying mechanisms — vascular health, inflammation, sleep, social engagement — run through all of them.

None of that comes in a bottle. All of it has evidence.

The Member deep-dive this week covers mild cognitive impairment in clinical depth — what the diagnosis actually means, the reversible causes that must be ruled out before accepting it, what cognitive testing involves and when to ask for it, and what the supplement evidence actually shows for brain health.

Next week: The direct-to-consumer wellness industry — AG1, Balance of Nature, and what the evidence shows about the products being marketed most aggressively to adults over 50.

Plain Medicine is published for educational purposes only and does not constitute medical advice or establish a patient-provider relationship. Always consult your healthcare provider before making medical decisions.

— Kyle