News Release

Chewing ability linked to reduced dementia risk

Peer-Reviewed Publication

Karolinska Institutet

Can you bite into an apple? If so, you are more likely to maintain mental abilities, according to new research from Karolinska Institutet in Sweden.

The population is ageing, and the older we become the more likely it is that we risk deterioration of our cognitive functions, such as memory, decision-making and problem solving. Research indicates several possible contributors to these changes, with several studies demonstrating an association between not having teeth and loss of cognitive function and a higher risk of dementia.

One reason for this could be that few or no teeth makes chewing difficult, which leads to a reduction in the blood flow to the brain. However, to date there has been no direct investigation into the significance of chewing ability in a national representative sample of elderly people.

Now a team comprised of researchers from the Department of Dental Medicine and the Aging Research Center (ARC) at Karolinska Institutet and from Karlstad University in Sweden have looked at tooth loss, chewing ability and cognitive function in a random nationwide sample of 557 people aged 77 or older. They found that those who had difficulty chewing hard food such as apples had a significantly higher risk of developing cognitive impairments. This correlation remained even when controlling for sex, age, education and mental health problems, variables that are often reported to impact on cognition. Whether chewing ability was sustained with natural teeth or dentures also had no bearing on the effect.


The results are published in the Journal of the American Geriatrics Society (JAGS). The study was financed with grants from several funds, including the Swedish Council for Working Life and Social Research and the Swedish Research Council.

Publication: 'Chewing Ability and Tooth Loss: Association with Cognitive Impairment in an Elderly Population Study', Duangjai Lexomboon, Mats Trulsson, Inger Wårdh & Marti G. Parker, Journal of the American Geriatrics Society, online early view 4 October 2012.

For further information, please contact:

Professor Mats Trulsson
Department of Dental Medicine – Karolinska Institutet
Tel: +46 (0)8-5248 8036 or +46 (0)70-636 8036

Professor Marti G. Parker
Aging Research Center – Karolinska Institutet and Stockholm University
Tel +46 (0)8 690 6869
Websites: and

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