Researchers at University of Florence who carried out the study stated, "Physical exercise may be the best way to keep the brain sharp in old age."
Meta-analysis of 15 prospective studies
In order to investigate the link between physical activity and risk of cognitive decline in non-demented subjects, the researchers conducted a systematic meta-analysis of all the available data.
For this purpose, they carried out an extensive search through MedLine, Embase, Google Scholar, Web of Science, The Cochrane Library and bibliographies of related articles up to January 2010.
Following the review, 15 studies were included in the final analysis. These studies included 33,816 mentally healthy subjects who were tracked for a period of one to 12 years.
Revelations of the study
During the follow-up period it was noted that 3,210 of the study subjects exhibited signs of cognitive decline.
The investigators also took into account factors such as age, education, smoking, alcohol, use of NSAID medication, self-rated health as well as certain chronic conditions that could have an impact on cognitive functioning.
The evaluation revealed that physical activity, whether moderate or strenuous, provided a substantial and constant defense against the development of cognitive decline.
The analysis revealed that the risk of cognitive deterioration was 38 percent lower in people involved in high levels of physical activity opposed to those who led a sedentary life-style.
Furthermore, it was noticed that even low-to-moderate level exercise reduced mental impairment by 35 percent.
Limitations of the study
According to the investigators, the techniques used to measure cognitive decline and physical activity differed across the studies included in the review.
Also, the study was unable to establish how increasing levels of exercise led to higher protection against mental impairment.
