Why chewing well is much more important than you think, according to science
Science discovered that chewing well goes far beyond helping with digestion. Its effects on the brain, the immune system, and appetite control surprised the researchers themselves.
Chewing seems to be one of the most automatic and insignificant acts of the day. It is done without thinking, dozens of times, without giving it much importance. But the latest scientific evidence is radically changing that perception. Different research teams have discovered that this everyday gesture activates mechanisms that go far beyond digestion and impact the immune system, brain function, appetite control, and mental health. What they found opens new lines of prevention for complex diseases and forces us to rethink something that is almost taken for granted.
The immune system starts in the mouth
One of the most surprising findings comes from a joint investigation between The University of Manchester and the National Institutes of Health in the United States. The study demonstrated that the simple act of chewing stimulates immune cells called Th17 in the gums, whose function is to protect the oral cavity against bacterial and fungal infections.
What was unexpected was the mechanism behind that activation. Biologist Joanne Konkel, part of the research team, explained that it is not the presence of bacteria that triggers this protective response, but chewing itself. The constant friction of food generates micro-damage in the gums that activates the factors responsible for producing these defensive cells. Until now, it was believed that this type of immune mechanism was only activated by contact with beneficial bacteria, as occurs in the intestine or skin. The mouth, it seems, works differently.
However, this finding has a less favorable side. Overstimulation of Th17 cells can be counterproductive and associated with periodontitis, a disease that not only affects dental health but is also linked to complications such as diabetes, rheumatoid arthritis, cardiovascular diseases, and premature births. As in many other biological processes, balance is key.
Chewing well preserves memory and slows cognitive decline
The relationship between chewing and the brain is one of the most active areas of current research. Studies reviewed by Japanese and European teams documented that the loss of chewing ability, common in older adults due to tooth loss or the use of soft diets, is associated with progressive cognitive decline and a higher risk of dementia.
The mechanism involves several neurosensory pathways. The information generated by the chewing movement travels to the hippocampus, the brain region key for memory and learning, through circuits that include the trigeminal nerve, the thalamus, and the cerebral cortex. This sensory stimulus promotes neurogenesis, that is, the formation of new neurons, and synaptic plasticity, two essential processes for keeping memory active as the years go by.
When that stimulus is reduced due to tooth loss or an excessively soft diet, the hippocampus receives fewer signals. The result is a lower neuronal and synaptic density that accelerates cognitive decline in older adults. Maintaining dental health and chewing foods with different textures emerges, in this context, as a concrete and accessible preventive strategy.
An unexpected ally against stress
The effects of chewing on the brain are not limited to aging. Trials conducted under stress conditions demonstrated that chewing helps counteract the suppression of neurogenesis that stress causes in the hippocampus, thus preserving the capacity for learning and memory even in times of high pressure.
The explanation is hormonal: chewing under stress modifies cortisol secretion and improves the brain's adaptability to adverse situations. In humans, even chewing sugar-free gum showed immediate improvements in memory tests and reaction times, an effect attributed to increased cerebral blood flow and the modulation of key neurotransmitters for cognitive functioning.
It is not a replacement for other stress management strategies, but rather a simple and underestimated tool that science is beginning to take seriously.
The role of chewing in appetite control
Another of the mechanisms that research is unraveling is the influence of chewing on the hormones that regulate hunger and satiety. Hormones such as cholecystokinin, glucagon-like peptide 1, ghrelin, and peptide YY respond directly to the chewing process and influence the sensation of fullness and gastric emptying.
The evidence suggests that slow and mindful chewing promotes the secretion of hormones that signal to the brain that it is enough, helping to regulate meal sizes without any additional effort. This mechanism is particularly relevant in the prevention and treatment of obesity and type 2 diabetes, two of the most widespread metabolic conditions globally.
Eating quickly, on the other hand, reduces the time available for these hormonal signals to reach the brain, which favors excessive intake almost without the person noticing.
An everyday gesture with profound consequences
What science is revealing about chewing forces a change in how we think about this automatic act. It is not about good manners or vague recommendations to "eat slowly." It is about a complex physiological process that activates immune responses, stimulates the brain, regulates hormones, and protects long-term health.
Experts agree on recommending a varied diet that includes foods of different textures and regular care of oral health as an integral part of healthy aging. Two simple habits that, in light of this evidence, carry much greater weight than they are usually recognized.
Chewing well does not change life overnight. But with awareness and regularity, it can be a small habit with a great impact on our overall health.