People who exercise and have higher physical fitness levels during middle age have a significantly reduced risk of developing dementia later in life.
The finding came from a new study conducted by Laura F. DeFina, MD, of The Cooper Institute in Dallas, and her team, and was published in the journal Annals of Internal Medicine.
Similarly, a study published in Archives of Neurology indicated that people over the age of 90 who have poor physical performance are at increased risk of developing dementia. In that report, a physical task was considered standing with good balance, walking, and getting up from a chair.
Dementia can be defined as the continuous deterioration in cognitive function - the ability to process thought. The deterioration is more than what is typically experienced in normal aging and results from damage or disease, most commonly Alzheimer's disease.
There were 19,458 non-elderly adults involved in the new study who were asked to take an exercise treadmill test between 1971 and 2009, so that the researchers could evaluate their baseline fitness levels.
In order to analyze the association between cardiorespiratory fitness levels during middle age and the development of dementia in advanced age, the scientists examined Medicare data for the individuals who became eligible to receive benefits between January 1, 1999 and December 31, 2009.
A diagnosis of all-cause dementia was considered for patients who had at least one skilled-nursing facility, hospital outpatient, home health agency, inpatient, or physician or supplier claim with any diagnosis code correlating with senile dementia, presenile dementia, and Alzheimer's disease among patients with three or more years of Medicare coverage.
Four codes linked to vascular dementia were also incorporated. At ages 70, 75, 80, and 85, the authors recorded whether or not the patients were affected by dementia.
Results showed that the individuals who were physically fit earlier in life had a significantly reduced chance of developing dementia, compared to those were not as physically fit.
The investigators concluded:
"Higher midlife fitness levels seem to be associated with lower hazards of developing all-cause dementia later in life. The magnitude and direction of the association were similar with or without previous stroke, suggesting that higher fitness levels earlier in life may lower risk for dementia later in life, independent of cerebrovascular disease."
A scientist in an Accompanying Editorial pointed out that although physical activity is linked to many health advantages, it can still be challenging to get patients to follow an exercise routine.
However, the editorial explained, the results of this research should encourage people to increase their levels of physical activity, as Alzheimer's is one of the most feared diseases among Americans.
Written by Sarah Glynn