Forget about crosswords and brain-training apps. There’s a new brain booster in town: chewing. But not just any chewing — chewing something hard.
Researchers recently have found that gnawing on tough materials, like wood blocks, can increase levels of a brain antioxidant linked to better memory and cognitive function. The findings, which may surprise many, reveal how something as mundane as chewing could play a role in protecting our brains from decline.
The Surprising Role of Chewing in Brain Health
Chewing is something most of us do without a second thought. Whether it’s a crunchy carrot or a soft piece of bread, our jaws move rhythmically, our teeth grind, and our tongues push food around effortlessly. But beneath this simple everyday act lies a stunningly complex neural dynamic.
Chewing is a rhythmic behavior, much like breathing or walking. It’s controlled by a network of neurons that fire in precise patterns, ensuring that the jaw, teeth, and tongue work in harmony. Sensory neurons in the mouth act as the first responders, sending signals to the brain about the texture, size, and hardness of the food. These signals are then relayed to rhythmic neurons, which generate the patterns of electrical activity that drive chewing.
“If you’re chewing on a carrot or a peanut that has a different consistency than chewing gum or something softer, then your mouth needs to know where the food is, where it’s positioned, and how hard it is, to predict how much pressure to apply,” said Arlette Kolta, a neuroscientist at the University of Montreal, who led a 2015 study that discovered that another type of cell that plays a role in the brain-mastication coordination process: astrocytes.
Previous studies found that chewing engages multiple regions of the brain, from the prefrontal cortex to the hippocampus — areas critical for memory, attention, and decision-making. Now, researchers from Kyungpook National University in South Korea found that chewing releases a molecule called glutathione, a powerful antioxidant that helps protect the brain from oxidative stress, which is linked to aging and neurodegenerative diseases like Alzheimer’s.
The Chewing Study
The study involved 52 healthy university students who were divided into two groups: one chewed paraffin wax gum, while the other chewed on wood blocks. Before and after the chewing sessions, the researchers used a specialized MRI technique to measure levels of glutathione in the participants’ brains. They focused specifically on the anterior cingulate cortex, a region involved in cognitive control. They also assessed the participants’ cognitive function using a standardized neuropsychological test.
While both groups showed some changes, the wood-chewing group experienced a significant increase in brain glutathione levels. “Chewing moderately hard material leads to an increase in the GSH concentration in the brain,” the researchers wrote. This boost in glutathione was also correlated with improvements in memory function, particularly in tasks involving working and story memory (the ability to retain and recall narratives or sequences of events over a longer period). In contrast, the gum-chewing group showed no significant changes in glutathione levels or cognitive performance.
So, why does chewing something hard make a difference? The researchers believe that chewing harder materials increases cerebral blood flow, delivering more oxygen and nutrients to the brain. This, in turn, might stimulate the production of glutathione, helping to neutralize harmful reactive oxygen species that can damage brain cells.
“The brain is especially vulnerable to oxidative stress,” the study notes.
A Brain Health Hack?
Glutathione levels naturally decrease with age, and this decline is thought to contribute to the onset of neurodegenerative diseases. While there are currently no effective ways to directly boost brain glutathione levels — oral supplements are quickly broken down in the gut, and intravenous treatments have a short lifespan in the bloodstream — this study suggests that something as simple as chewing harder foods could offer a practical solution.
Of course, that doesn’t mean that you need to chew wooden sticks. Raw vegetables like carrots and celery, nuts and seeds like almonds and walnuts, or fruits like apples and pears should work just as well. Incidentally, these are also healthy foods, so this is just another good reason to include them more in your diet.
As a caveat, the study has its limitations. The participants were young adults, and the effects of chewing on brain health might differ in older populations. The research also focused on a single brain region, leaving open the question of whether other areas might respond differently. And while the study controlled for the hardness of the materials, it didn’t account for other factors, like texture or taste, that could influence the results. Questions remain about the optimal type and duration of mastication required to boost brain health.
Still, the findings add to a growing body of evidence that chewing is more than just a mechanical process. It’s a brain-boosting activity that could have far-reaching implications for how we think about cognitive health.
The findings appeared in the journal Frontiers in Systems Neuroscience.
