Your brain shrinks after 40. Learning a musical instrument can reverse it.

National Geographic

16 hours ago

Experts say the more we challenge our brains as we age, the more resilient it becomes—and 'learning a new instrument is a full-brain workout.' After the age of 40, the average brain decreases 5 percent in volume every decade, and brain degeneration hits peak acceleration around age 67. But one effective method for slowing neurodegeneration is learning an instrument. Photograph by Dimitri Otis, Getty Images
No matter how much we may try, we can't fight most effects of getting older. Eyesight fades, wrinkles deepen, and joint pain becomes almost inevitable. But cognitive decline? That might be more flexible than we think.
Although research shows the brain loses about 5 percent of its volume per decade after age 40, scientific findings suggest that picking up a new skill—like learning a musical instrument—can help preserve brain function well into our golden years.
That's the message underscored in the first episode of Limitless: Live Better Now, streaming on Disney+ and Hulu starting August 15, and on National Geographic starting August 25. In the episode, 41-year-old Australian actor Chris Hemsworth takes up drumming for the first time. In doing so, he's not just preparing to play in front of 60,000 screaming fans at an Ed Sheeran concert—he's demonstrating how learning an instrument later in life could support the health of his own aging brain.
This isn't a superpower for Hemsworth alone. A growing body of research suggests that activities that challenge the mind can be powerful tools in combating age-related cognitive decline.
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The gradual loss of brain tissue, known as brain atrophy, can begin as early as our 30s, "but it doesn't happen to everyone at the same rate,' says Daniel Gustavson, a cognitive psychologist at the University of Colorado Boulder.
When it does occur, atrophy often affects key areas like the prefrontal cortex, which is responsible for problem solving and adaptability, and the hippocampus, which governs memory and spatial navigation.
'You might notice decline in these areas when you struggle to recall details from a conversation or forget where you placed your keys,' explains Maya Shankar, a cognitive scientist featured on the Limitless series. 'When these things occur, they're more than just annoying—they reflect real changes in neural connectivity.'
Brain shrinkage is largely driven by the loss of neurons and specialized junctions in the brain called synapses, as well as a reduction in plasticity—the brain's ability to adapt and reorganize. Another contributing factor is the age-related decline in production and efficiency of neurotransmitters like dopamine, serotonin, and acetylcholine—a chemical messenger critical to memory and muscle movement. As these neurotransmitters decline, so does mental sharpness.
To make matters more complex, both gray and white matter also diminish with age. These nerve tissues play critical roles in protecting and supporting neural connections. Their deterioration can lead to a variety of symptoms, the severity of which often depends on genetics and lifestyle, says Golnaz Yadollahikhales, a neurologist at Cedars-Sinai Medical Center in Los Angeles.
While mild forgetfulness is common, she notes that more significant memory loss could be a sign of the early stages of cognitive decline or dementia. How mentally challenging activities help future-proof the brain
The antidote to age-related cognitive decline, scientists agree, is neuroplasticity—the brain's lifelong ability to rewire itself in response to new experiences. 'When we learn something new, we're literally building new neurons and pathways,' Shankar says. She likens it to finding a new route to work when your usual one is closed.
This adaptability underpins what researchers call cognitive reserve—the brain's capacity to compensate for age-related damage or changes. Yadollahikhales describes it as 'mental scaffolding' that helps keep you functioning even if one part of your brain starts to falter.
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An effective way to build cognitive reserve is by learning new, cognitively-demanding skills such as 'picking up a new sport, painting, cooking, writing, coding, dancing, or learning a new language,' says Shankar. These types of activities enhance white matter integrity, support healthy neurotransmitter activity, and improve communication between brain hemispheres by strengthening the corpus callosum, the brain's largest white matter tract.
'It's like a bridge because it plays a crucial role in communication between the right and left hemispheres,' says Yadollahikhales. Stronger inter-hemispheric connections can improve everything from multitasking to emotional regulation. Why learning a new instrument can help offset brain shrinkage
While many skills can stimulate the brain, 'learning a new instrument is probably the biggest bang for your brain buck,' Shankar says. That's because playing a musical instrument enhances executive function and working memory by 'engaging nearly every brain region and strengthening communication between them,' she explains.
Playing a musical instrument involves bimanual coordination and activates multiple brain structures simultaneously, thereby strengthening the corpus callosum. Some of these brain structures include those responsible for hearing, reading music, and coordinating hand and finger movement.
'Learning a new instrument is a full-brain workout,' says Gustavson. 'And that makes it a potent tool for building cognitive reserve.'
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Plenty of research backs this up. A 2022 Frontiers in Aging Neuroscience study found that older adults who received piano training for six months showed improved structural connectivity in brain regions associated with memory and language.
Other studies show that learning an instrument later in life can also boost memory, executive function, and even brain volume. In one trial, seniors with no prior music experience improved their verbal memory after just three months of learning the keyboard harmonica, a small handheld keyboard powered by the breath. How to get started learning a new instrument
If you want to use music to protect your brain health, choosing the right instrument matters. 'Pick one that excites you but also challenges you,' advises Yadollahikhales. 'If it's too easy, it won't stimulate neuroplasticity. If it's too hard, you'll quit. It needs to sit in that sweet spot of 'just hard enough.''
Piano, guitar, and drums are frequently recommended for their demand on bilateral coordination, but Gustavson emphasizes that most instruments can be effective—as long as they require sustained effort. 'Follow your heart, because the best instrument is the one you'll stick with,' he says.
Shankar also suggests thinking practically. 'Ask yourself: Will I practice this regularly? Do I enjoy the sound? Do I feel moved by what I'm learning?' Motivation matters, she says, because engagement is key to reinforcing new neural pathways.
For those hesitant to take formal lessons, other options include how-to apps, YouTube tutorials, or adult-friendly group classes. 'The social component of learning music can be just as powerful as the cognitive one,' adds Gustavson. 'It improves mood, encourages accountability, and adds a layer of fun.'
Most importantly? Start where you are, no matter your age. 'It's never too late,' says Michael Snyder, a genetics professor at Stanford School of Medicine. While it's easy to assume learning is just for the young, he says, it's the struggle itself—not the mastery—that fuels brain growth at any age.
In the end, we may not be able to stop the clock, but we can push back against its effects.
'It's easy to despair over age-related degradation of the brain, but all the research on neuroplasticity actually gives us reason to hope," Shankar offers. 'If our brains remain moldable throughout life, we can shape their trajectory and improve both our everyday experiences and our future.' "Limitless: Live Better Now" is streaming on Disney+ and Hulu starting August 15 and on National Geographic starting August 25. Check local listings.