Sodium Linked to Cognitive Decline in Elderly

Does losing one's memory and ability to think clearly have to be part of aging? Obviously not, as there are plenty of people in their 90s who are as sharp as a tack.

So what accounts for some older people retaining their cognitive ability and others losing it?

Canadian researchers pondering that question have shed some new light on the subject. They have concluded 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. They say they have found evidence that high-salt diets coupled with low physical activity can be detrimental to cognitive health as you age.

The study by researchers Baycrest in Toronto and Institut Universitaire de Gériatrie de Montréal, may have significant public health implications, emphasizing the importance of addressing multiple lifestyle factors that can impact brain health.

Sodium's impact on the brain

"We have generated important evidence that sodium intake not only impacts heart health, but brain health as well," said Dr. Alexandra Fiocco, a scientist with Baycrest's Kunin-Lunenfeld Applied and Evaluative Research Unit (KLAERU) and the study's lead investigator.

While low sodium intake is associated with reduced blood pressure and risk of heart disease, this is believed to be the first study to extend the benefits of a low sodium diet to brain health in healthy older adults.

The study followed the sodium consumption and physical activity levels of 1,262 healthy older men and women (ages 67 – 84) residing 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).

Limit sodium to 2.300 mg per day

Most public health experts suggest people 14 years of age and older consume no more than 2,300 mg of sodium per day in their diet. For the purpose of the study, low sodium was defined as being below that amount, while high sodium consumption was set at nearly 3.100 mg, of higher, per day.

Physical activity levels were measured using the Physical Activity Scale for the Elderly.

"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," said Fiocco. "But 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."