It may be easier to avoid Alzheimer’s and dementia if you frequently bite into hard food. A Swedish study on aging shows that if, as you grow older, you can still chomp down on chewy foods like apples, you run a lower risk of losing your mental abilities.

The researchers examined tooth loss, chewing ability and cognitive function in a random sample of 557 Swedes aged 77 or older. Those who had difficulty chewing hard items such as apples had a significantly higher risk of developing cognitive disorders. The correlation between chewing and cognition remained even when sex, age, education and mental health problems (variables that are often reported to impact on cognition) were controlled. They also found that whether a person had dentures or his own teeth made no difference, as long as he could still chew.

The researchers think that hard chewing may help stimulate blood flow to the brain that helps to keep this organ from deteriorating.