Chewing and Brain Function
A Broad Impact on Health
Who would have thought that the action of chewing food had a role other than to start the digestion process! Increasing research studies have found that mastication (technical term for the the action of chewing food) has a major impact on many aspects of our health. Chewing and brain function effects have been found in connection to learning, memory, focus and concentration.
Raw fruit and vegetables, nuts and seeds and meat all demand more chewing. Many processed foods and cooked foods are softer and easier to chew through. One of my pet hates when it comes to commercial food products are those ridiculous pouches of soft pureed fruit that kids consume direct from a tube, instead of chewing through an apple or orange! Now we know that this will have a negative impact on their brain, memory and learning.
On average, it is estimated that we chew 800 to 1,400 times a day. We generally recommend chewing our food slowly, at least around 15 times, but for many foods we don’t need that long and realistically swallowing is in an instinctive behaviour. We simply know when food is chewed well enough and then we naturally swallow. While it may seem logical that easy to digest food is a good thing, in reality we haven’t evolved with soft foods. Many of the pathways that stimulate digestive juices and gut motility (that are essential for digestion) stem from the action of chewing and the taste of foods. Bitter foods for example are highly stimulating for digestion and chewing sends signals to the brain that stimulate the gut to prepare for food.
Good Teeth Are The Key!
As we age, many people have declining memory and focus and concurrently may also suffer from poor dental function. With bad teeth, elderly people often resort to soft foods that don’t tax the teeth, however this may lead to unexpected negative consequences. Not only will the gut not get clear signals for digestive juice manufacture, we now know there are more broad problems that can arise in distant regions of the body. In particular, we know that mastication has a direct impact on learning and memory formation and so poor dental health can impact the brain. For instance, research has shown that the systemic effects of tooth loss are a risk factor for Alzheimer’s disease.
The hippocampus is the brain region that is involved with forming memories and it seems that the action of mastication, stimulates this area. Functional MRI studies can compare the difference in brain region activity in different populations. The acquisition of memory in elderly people was significantly enhanced by chewing, but benefits of chewing had less effects in younger people.
Interestingly, another study found that lower intakes of nutrient-dense foods and higher intakes of unhealthy foods were also both independently associated with smaller left hippocampal volume. So it seems that it is both the processed foods being both nutrient poor and requiring less chewing that create a perfect storm for brain impairments.
Researchers have also found that a reduction in corticosterone production is another way that mastication can have a role in poor brain function. Thus a chronic stress state is induced by poor chewing activity and this can in turn lead to learning and memory impairments. Concurrently, the act of chewing during stressful conditions was shown to attenuate the effects of stress on cognitive function. This has been further explored by some researchers with a recommendation to chew gum as a way of enhancing memory and cognition and delaying the development of dementia and also ameliorate the effects of stress on the brain.
So there are so many reasons to chew your food well, and make sure the foods you eat include some types that require lots of chewing – like raw veggies! Also, it serves that foundational to this whole approach is to also ensure optimal dental hygiene. So if you choose to chew gum to boost your memory, make sure it is sugar free or contains xylitol which has been shown to reduce oral bacteria and prevent gum disease.
To learn more about maintaining healthy teeth through whole foods – see this previous article.