One good way of slowing down your eating rate, in fact, is to eat more textured foods. Many studies recommend choosing solids over liquids (think oranges rather than orange juice), and high-viscosity foods over low-viscosity ones (oatmeal and flaxseeds instead of white rice or pasta).
“The texture of food can affect how full we feel, and therefore potentially help those struggling with obesity to lose weight by reducing their food intake,” says Kumar.
A boost for brain health
Nutrition and digestion aside, researchers are increasingly uncovering that chewing plays an important role in other aspects of our wellbeing – especially brain health – as we get older. “There is growing interest in the ‘bite–brain axis,’ which proposes that mastication is directly linked to brain health,” says Kumar. Tooth loss, for instance, has also been linked with a higher risk of Alzheimer’s disease and dementia.
Wouldn’t it be really cool if you can rehabilitate the brain by rehabilitating the dentition? – Mats Trulsson
Memory is affected, too. In a survey involving more than 28,500 people older than 50 across 14 European countries, participants with good chewing ability or those without dentures performed better on a battery of cognitive tests. They demonstrated significantly better word recall, verbal fluency, and numeracy skills than those with chewing problems. In one study of 273 healthy people between the ages of 55 and 80, scientists found that those who retained a greater number of their natural teeth had better semantic memory (linked to knowledge and facts of the world) and long-term memory.
But why does chomping ability have anything to do with memory? Some researchers point to the multiple neural circuits connecting our chewing apparatus to the hippocampus – the region of the brain responsible for spatial learning and making new memories, which is one of the first to be damaged by Alzheimer’s. Others suggest that chewing, especially moderately hard substances, may increase blood flow to the brain, as Japanese researchers demonstrated in experiments with gum chewers. “The theory is that chewing works like a pump, pumping blood to the brain,” explains Trulsson. This keeps the brain sharp and working well, he says.
To determine whether poor chewing ability can actually cause cognitive decline, and whether rehabilitation is possible, Trulsson’s team is currently running an experiment replacing patients’ missing teeth with implants and then studying their brain function before and up to a year after the procedure. MRI brain scans will also be used to examine if white matter lesions, a marker of poor brain vascular health, shrink with treatment.
“Wouldn’t it be really cool if you can rehabilitate the brain by rehabilitating the dentition?” says Trulsson, who has recruited over 80 patients for his trial so far.
Heightening alertness
In some instances, chewing has also been found to improve concentration in the general population. One meta-analysis, comprising 21 studies, detected a weak but statistically significant improvement in attention levels of gum-chewing participants compared to non-chewers during some cognitively demanding tasks. (This research was funded by gum manufacturer Mars Wrigley, suggesting a potential conflict of interest.)
In an unrelated study of 80 participants, chewing improved alertness levels by 10% during a series of cognitive tasks. Gum-chewers also performed better on an intelligence test.
