The study, published in the journal Neurobiology of Aging, reports that older adults who lead sedentary lifestyles and consume a lot of sodium in their diet may be putting themselves at risk for more than just heart disease.
The researchers, led by Dr. Alexandra Fiocco from the University of Toronto, Canada, said the findings may have significant public health implications, by emphasizing the importance of addressing multiple lifestyle factors that can impact brain health.
“We have generated important evidence that sodium intake not only impacts heart health, but brain health as well,” said Fiocco.
“The results of our study showed that a diet high in sodium, combined with little exercise, was especially detrimental to the cognitive performance of older adults,” she explained.
The study followed the sodium consumption and physical activity levels of 1,262 healthy older men and women living in Quebec, Canada, over three years. The adults were recruited from a large pool of participants in the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge).
Participants were assessed as low, mid or high level sodium consumers based on a food frequency questionnaire they each completed. The researcher team then used a modified Mini-Mental State Examination to measure cognitive function in participants at year one (baseline) and annually for three additional years.
While a sedentary lifestyle and high salt intake was found to be associated with cognitive decline, the researchers noted that individuals with low activity levels, but low sodium intake were associated with cognitive maintenance over 3 years.
“Thus, the combination of low levels of physical activity and high levels of sodium intake is particularly detrimental to cognitive health,” said the researchers.
“This study suggests that sodium intake reduction, especially in low physical activity older adults, may further improve brain health in late life,” they added.
“The good news is that sedentary older adults showed no cognitive decline over the three years that we followed them if they had low sodium intake,” said Fiocco.
Dr. Carol Greenwood, senior author of the study added that the data from the study is “especially relevant as we know that munching on high-salt processed snacks when engaged in sedentary activities, such as watching TV or playing in front of the computer, is a frequent pastime for many adults.”
Source: Neurobiology of Aging
Published online ahead of print, doi: 10.1016/j.neurobiolaging.2011.07.004
“Sodium intake and physical activity impact cognitive maintenance in older adults: the NuAge Study”
Authors: A.J. Fiocco, B. Shatenstein, G. Ferland, H. Payette, et al