Self-rated physical fitness in midlife an indicator of dementia risk

A recent collaborative study from Finland, involving the follow-up of 3,559 adults for 30 years, has found that a simple question about self-rated physical fitness in midlife may reveal individuals who are at an increased risk of developing dementia. Those who reported poor self-rated physical fitness in midlife, at the mean age of 50 years, were four times more likely to get dementia during the next three decades compared to those with good self-rated physical fitness.

"Previous research has shown that self-rated health is a strong indicator of adverse health events. This is the first large population-based study investigating associations between self-rated physical fitness during the three decades from midlife to later life and dementia risk," says Postdoctoral Researcher, Dr Jenni Kulmala from the Gerontology Research Center at the University of Jyväskylä, Finland.

The association between poor self-rated physical fitness and dementia was most pronounced among noncarriers of the apolipoprotein E ε4 allele, that is, people who did not have a strong genetic susceptibility for dementia. A strong association was also observed among people with chronic diseases.

"Chronic conditions independently increase the dementia risk. Furthermore, if a person additionally feels that his or her physical fitness is poor, the risk is even higher. In terms of dementia prevention, maintaining good physical fitness seems to be especially important for people with chronic diseases," Kulmala says.

Poor self-rated fitness is known to be affected by lifestyle factors such as physical inactivity, poor mental wellbeing, lack of social connections, lower education, high body mass index and smoking. Perceived poor physical fitness therefore integrates several unfavourable aspects of lifestyle that have all been previously linked to increased dementia risk.

"The perception of poor physical fitness is most likely affected by different factors for different people. Therefore, I would encourage those who rate their fitness as poor to think about the factors behind this perception. Increasing physical and social activity, making better dietary choices or quitting smoking, for example, could change the rating into more positive. Individual choices that make you feel physically better may substantially decrease your future risk of developing dementia," Kulmala says.

The participants in this study came from the Cardiovascular Risk Factors, Aging and Incidence of Dementia (CAIDE) study, which is an ongoing joint effort of the Department of Neurology at the University of Eastern Finland, Kuopio; the National Institute of Health and Welfare, Helsinki, Finland; and the Aging Research Center of Karolinska Institute, Stockholm, Sweden. The aim of the CAIDE study is to investigate the connection between social, lifestyle and cardiovascular risk factors and cognition and dementia. The Academy of Finland has funded the research through Jenni Kulmala's project.

Journal Reference:

Jenni Kulmala, Alina Solomon, Ingemar Kåreholt, Tiia Ngandu, Taina Rantanen, Tiina Laatikainen, Hilkka Soininen, Jaakko Tuomilehto, Miia Kivipelto. Association between mid- to late life physical fitness and dementia: evidence from the CAIDE study. Journal of Internal Medicine, 2014; DOI: 10.1111/joim.12202