The study reviewed the data of 295 men, born between 1900 and 1920, from the Finland, Italy and Netherlands Elderly (FINE) Study. Beginning in 1990, researchers measured the duration and intensity of physical activities such as walking, bicycling, gardening, farming, sports, odd jobs, and hobbies. Cognitive functioning was tested with the Mini Mental State Examination.
The study showed that over 10 years the cognitive decline in men who had reduced their daily physical activity by an hour or more was 2.6 times greater than the decline in men who maintained their activity.
Men who performed their daily physical activity with a lower intensity 10 years later had a 3.6 times stronger decline than men who maintained the intensity level. Men who engaged in activities of the lowest intensity had up to 3.5 times greater decline than men who participated in activities with a higher intensity. There was no decline among those who increased the duration or intensity of their activities.
Activities of medium-to-low intensity, such as walking three miles per day, was associated with less cognitive decline than the lowest-intensity activity like walking less than three miles per day. The benefit of the medium-to-low intensity activities is that it will be easier for people to participate in them and achieve favorable results, compared with activities with a higher intensity, according to study author Boukje M. van Gelder, MSc.
"Our study suggests that being physically active in old age could keep the brain fit," said van Gelder, of the National Institute for Public Health and the Environment in Bilthoven, the Netherlands.
Physical activity may improve blood flow to the brain and thereby reduce the risk of stroke, dementia, and cognitive decline. Activity may stimulate the neurogenesis, or growth of nerve cells, in the hippocampus, the region of the brain involved in memory functions. This helps the brain build up a "reserve" to help prevent further mental deterioration.
Past studies have suggested a link between levels of activity and cognitive decline in the elderly, but differences in methodologies make it difficult to conclusively determine the relationship.
"The small number of healthy participants in the FINE study is a disadvantage but the study's length is an advantage, and the results were consistent and significant," said van Gelder. "Future research should include more extensive cognitive testing than the Mini Mental State Exam, which is reliable but is only a screening test."
The FINE study is a part of the HALE project (Healthy Aging: Longitudinal study in Europe) and was supported by a grant from the European Union.
The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Parkinson's disease, ALS (Lou Gehrig's disease), dementia, West Nile virus, and ataxia.
For more information about the American Academy of Neurology, visit its Website at www.aan.com.