8 Brain Health Myths You Should
Stop Believing Right Now

Brain health is one of those topics where popular culture has decisively outrun the science. Phrases we've heard since childhood — "we only use 10% of our brains," "left-brained people are logical, right-brained people are creative," "crossword puzzles keep your mind sharp" — have become so embedded in everyday conversation that most people accept them without question. The problem is that many of them are simply wrong, and some may actually lead people away from the habits and strategies that genuinely support a healthy mind.

Here, we take eight of the most widespread brain health myths and hold them up to the light. What does the science actually say? And more importantly — what should you be doing instead?

Myth 1: We Only Use 10% of Our Brain

This might be the most durable myth in all of neuroscience. The idea that vast reserves of untapped brain potential are just waiting to be unlocked sounds inspiring — it has driven everything from self-help books to blockbuster movies. But it has no basis in reality.

Brain imaging technology — including functional MRI and PET scans — consistently shows that virtually all regions of the brain are active throughout the day. Different regions activate depending on what you're doing: the motor cortex fires when you move, the visual cortex processes what you see, and so on. Over the course of a full day, essentially every part of the brain sees significant activity.

From an evolutionary standpoint, a brain that used only 10% of its tissue would be extraordinarily wasteful. The human brain represents about 2% of body weight but consumes roughly 20% of the body's energy. Evolution doesn't preserve expensive organs that sit largely idle.

The "10% myth" likely originated from misinterpretations of early neuroscience research and William James's writings on human potential — not from any actual brain imaging data.

Myth 2: Crossword Puzzles Prevent Dementia

The idea that keeping your mind active through puzzles will ward off cognitive decline is appealing, and it's not entirely without merit. Mental engagement matters. But the specific claim that crossword puzzles prevent dementia has significantly overstated the evidence.

Research suggests that regular crossword practice makes you better at crosswords — a phenomenon called "near transfer." The cognitive skills you use solving a crossword don't easily transfer to unrelated cognitive tasks, a finding referred to as the "far transfer" problem. The 2014 ACTIVE trial, one of the largest brain training studies ever conducted, found that specific cognitive training improved performance in the trained domain but didn't reliably reduce dementia risk in general.

What does appear to offer broader protection? A combination of physical exercise, quality sleep, diverse social engagement, stress management, and a nutritious diet — not any single mental activity in isolation.

Myth 3: Memory Loss Is Inevitable After 50

The assumption that significant memory decline is an unavoidable rite of passage of middle age has discouraged many people from taking action at the very time they could make a meaningful difference. The reality is considerably more nuanced.

Some aspects of memory do change with age — processing speed slows, working memory becomes somewhat less efficient, and retrieval of specific details may take longer. But "slower" is not the same as "broken." Many people remain cognitively sharp and functional well into their 70s, 80s, and beyond. The degree of decline varies enormously from person to person and is profoundly influenced by lifestyle factors that are within your control: physical activity, diet quality, sleep, stress levels, social connection, and ongoing mental engagement.

Treating memory decline as inevitable creates a self-fulfilling prophecy. People who believe their memory will fail tend to make less effort to protect it — and may notice every small lapse far more acutely than people who expect to stay sharp. Learn more in our article on why memory declines with age.

Myth 4: Brain Training Apps Make You Smarter

The commercial brain training industry has generated billions of dollars on the promise that a few minutes of daily app-based puzzles will enhance general intelligence, prevent cognitive decline, and sharpen memory. Unfortunately, the scientific evidence doesn't support these broad claims.

In 2014, a statement signed by more than 70 leading neuroscientists and cognitive psychologists cautioned consumers that the claim that brain games offer consumers a scientifically grounded way to improve broad cognitive functions is not supported by the scientific literature. The consensus remains largely the same today — brain training games improve your score on those specific games but don't produce meaningful general cognitive improvement.

This doesn't mean mental stimulation has no value. Learning genuinely new skills — a foreign language, a musical instrument, a new craft — does challenge the brain in ways that may support neuroplasticity. The difference is novelty and genuine difficulty. If an activity becomes easy, it's no longer sufficiently challenging to drive adaptation.

Myth 5: You're Either Left-Brained or Right-Brained

Pop psychology has long promoted the idea that logical, analytical people are "left-brained" while creative, artistic people are "right-brained." It's a tidy narrative — but it doesn't reflect how brains actually work.

A large 2013 study analyzing brain imaging data from over 1,000 participants found no evidence of consistent left-brained or right-brained dominance at the individual level. While it's true that certain functions are somewhat lateralized — language processing often involves more left-hemisphere activity, for instance — the brain works as a highly integrated system. Creative tasks draw on both hemispheres. So do analytical ones.

The harm in this myth is that it encourages people to mentally limit themselves — "I'm not a math person, I'm right-brained" — based on a neurological fiction.

Myth 6: Alcohol Kills Brain Cells

This myth is partly right but mostly misleading. Acute alcohol intoxication does not directly kill neurons the way it's often described. What alcohol does — particularly with chronic heavy use — is damage the dendrites (branching extensions) of neurons that facilitate communication, disrupt neurogenesis (the formation of new brain cells), and cause widespread disruption to brain circuits and neurotransmitter systems.

Chronic heavy drinking is clearly damaging to brain health. It increases the risk of dementia, impairs memory consolidation, and can lead to thiamine (Vitamin B1) deficiency — which causes Wernicke-Korsakoff syndrome, a severe memory disorder.

However, occasional moderate alcohol consumption has a different (though still debated) profile. The key takeaway: heavy, chronic alcohol use is genuinely harmful to the brain, but the mechanism is more complex than "each drink kills X brain cells."

Myth 7: You Can't Grow New Brain Cells as an Adult

For most of the 20th century, mainstream neuroscience held that the adult brain was essentially fixed — you were born with a set number of neurons, and from then on it was a slow process of attrition. This is now known to be incorrect.

The discovery of adult neurogenesis — the formation of new neurons — in the hippocampus overturned this assumption. Research has shown that the hippocampus, the brain's primary memory-formation hub, continues to generate new neurons throughout adult life. The rate of neurogenesis is influenced by lifestyle: exercise promotes it, while stress and sleep deprivation suppress it.

Beyond neurogenesis, the concept of neuroplasticity extends throughout the brain. Existing neural connections are continuously strengthened, pruned, and reorganized in response to experience, learning, and environmental input. Your brain is far more malleable than the old science suggested.

Myth 8: A Poor Memory Is Just "Who You Are"

Perhaps the most limiting of all these myths is the belief that memory ability is a fixed trait — something you either have or you don't. This leads people to shrug off memory lapses as personality quirks rather than recognizing them as something that can be meaningfully supported and improved.

Memory is a skill that responds to practice, strategy, and — critically — to the conditions you create in your life. Sleep quality, exercise habits, diet, stress levels, and the specific memory techniques you use all influence how well your memory functions. People who adopt memory-supporting habits and use proven techniques (like spaced repetition, active recall, and elaborative encoding) consistently outperform those who rely on passive exposure alone.

Additionally, natural ingredients studied for cognitive support — including Bacopa Monnieri, Lion's Mane Mushroom, and Phosphatidylserine — have attracted research interest for their potential to support the neurological foundations of memory function. Supporting your brain with the right nutrients and lifestyle factors is very much within your control.*

*These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease.