5 Of the Worst Brain Myths

Don't make the mistake of believing these myths!

By Austin Perlmutter, MD

With our non-stop exposure to a 24-hour news cycle built around sensationalism and a social media algorithm based on novelty and attention capture, it’s no wonder that we find ourselves perpetually inundated with overstated, incorrect and sometimes completely contradictory information about our health. While half-truths and “miracle cures” abound, many key scientific breakthroughs of the last half century have been slow to make it into popular understanding. This has been incredibly damaging as it relates to brain health. In today’s article, we are breaking down 5 of the most problematic myths about your brain and setting the record straight using the latest science.

Myth 1: I should only start focusing on brain health when something's obviously wrong.

This is the costliest myth on the list, because it gets the timeline exactly backwards. Unfortunately, this myth is still incredibly common around the world.

The diseases we fear most, like Alzheimer's and related dementias, are very rarely sudden events. The underlying brain changes, including the accumulation of proteins like tau and amyloid, begin to unfold decades before the first symptom appears. By the time memory problems are obvious enough to send someone to a doctor, the process has often been quietly in motion since midlife or earlier.

Here's the hopeful flip side of that same fact. The 2024 report of the Lancet Commission on dementia prevention concluded that close to half of dementia cases worldwide are linked to modifiable risk factors like managing your blood pressure, getting your hearing tested and treated, getting regular physical activity, and prioritizing air quality. Other research indicates the preventable burden of dementia may be as high as 72%! The point that most people miss: it’s never too early to prioritize brain health and dementia prevention. The best day to start is today!

Myth 2: I can't really change my brain, I’m stuck with what I’ve got.

The idea that the brain is relatively fixed in adulthood remains for many people, the scientific consensus. Basically, you were handed a set number of neurons, and after you became an adult, you were locked in.

We now know that's wrong, and the evidence is genuinely remarkable. One of my favorite examples comes from London taxi drivers, who spend years memorizing the city's tangle of 25,000 streets. When researchers scanned their brains, they found that a memory-and-navigation region called the posterior hippocampus was measurably larger than in non-drivers, and the longer someone had driven, the bigger it was. The brain had physically reshaped itself in response to how it was being used. Read my full article on that topic HERE

That capacity is called neuroplasticity, and it doesn't stop at learning street maps. Even the old dogma that adults can't grow new neurons has been overturned. Recent human studies confirm that the hippocampus continues to generate new neurons into old age, a process shaped by things like exercise, sleep, and stress.

None of this means you can think your way to a new brain overnight. But the idea that you're a passive passenger in your own skull is simply not supported by the science. Your brain is an adaptive, living organ that responds to how you treat it, at every age.

Myth 3: The tools or hacks that matter most are the sexy ones I see online.

Open any wellness feed and you'll get the impression that brain health lives inside a bottle of “just developed” supplements or a slick device promising to sharpen your mind in five minutes a day. These products are engineered to feel important. They’re backed by billions of dollars of marketing spend. That doesn't make them effective.

Contrast that with the unglamorous fundamentals like physical activity, quality sleep, a nutrient-dense diet, social connection, managing blood pressure and blood sugar. These rarely trend online, yet they're the interventions with the deepest evidence base behind them for protecting the brain over time.

I'm not anti-innovation, and there are certain products and supplements with evidence behind them. But I've come to believe that the more a brain product leans on novelty and hype, the more skeptical we should be. The tools that move the needle tend to be the ones that are too ordinary to go viral.

Myth 4: If I can't do it perfectly, why bother?

This one is quieter than the others, but it probably more people than any single supplement ever could. It's the belief that brain-healthy habits only "count" if you hit some exact target the perfect number of steps, the ideal minutes of exercise, the flawless diet. Miss the mark, and you might as well not try.

The research tells a much more forgiving story. Consider a large 2022 study in JAMA Neurology that tracked daily step counts in nearly 80,000 adults. Yes, a higher count — around 9,800 steps a day  was associated with roughly a 50% lower risk of dementia. But here's the part I wish more people knew: even about 3,800 steps a day was linked to a 25% reduction. Half the "optimal" number still delivered a substantial share of the benefit.

That pattern of meaningful benefit at low doses, with diminishing returns as you push toward the top shows up across brain health research. The relationship isn't all-or-nothing. It's a dose-response curve, and the steepest, most rewarding part of that curve is often the move from nothing to something.

So if the "perfect" routine feels out of reach right now, do the imperfect version. A walk you take beats the ideal workout you keep postponing. Put on your shoes and go around the block, it’s not about doing a 5k! In brain health, consistency at a modest level almost always outperforms perfection you can't sustain.

Myth 5: My attitude about my brain doesn't affect my brain.

Of all five myths, this is the one that often surprises people the most and the science behind it is some of the most fascinating in the field.

It turns out that how you think about your own aging and mental future appears to shape that future. In a landmark study published in PLOS ONE, Yale researcher Becca Levy and colleagues followed older adults and found that those with positive beliefs about aging were significantly less likely to develop dementia. The most striking finding: among people carrying APOE-ε4, one of the strongest genetic risk factors for Alzheimer's, those with positive age beliefs were nearly 50% less likely to develop dementia than those with negative beliefs. Attitude appeared to help offset a genetic vulnerability.

It's not just age beliefs. A large analysis of the Health and Retirement Study found that higher optimism was associated with a lower risk of developing dementia over years of follow-up. And optimism has been linked to longer lifespan and better healthy aging more broadly.

Why would perspective matter this much? The likely mechanisms are refreshingly concrete. Negative beliefs about aging tend to raise chronic stress, and chronic stress is hard on the brain. People with a more hopeful outlook are also more likely to keep exercising, stay socially connected, and take care of their health, the very behaviors that protect cognition. Perspective isn't magic; it's an upstream force that shapes everything downstream.

Crucially, these beliefs aren't fixed. They can shift and that means your outlook is one more modifiable brain-health factor, not a fixed trait you're stuck with. For a deep dive on this topic, check out my full-length piece HERE

The bigger picture

There is a key trend running through these five myths: each one, in its own way, tells you to do less. Wait longer, try nothing because you can't change anyway, chase shortcuts instead of fundamentals, quit if you can't be perfect, assume your mindset is irrelevant.

The science points the other direction. Your brain is changeable across your entire life. The fundamentals matter more than the fads. Imperfect effort still counts. And even your outlook is part of the equation.

The bottom line? You have far more agency over your brain right now than most people believe, and that is a real truth worth remembering.

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This content is for informational and educational purposes only and does not constitute medical advice. Please consult with a qualified healthcare provider before making significant changes to your diet or lifestyle.