Dubai: Older men who consume more salt may experience faster memory decline, according to an Australian study that found a possible link between higher sodium intake and deteriorating cognitive performance in men, but not women.
The research, led by scientists at Edith Cowan University (ECU) and published in the peer-reviewed journal Neurobiology of Aging, found that men with higher sodium consumption experienced a significantly faster decline in episodic memory, which allows people to recall personal experiences, past events and everyday details, such as where they left their keys.
The study, titled Higher sodium intake is associated with episodic memory decline in cognitively unimpaired older males: A 6-year longitudinal study, examined 1,208 cognitively unimpaired older adults with an average age of approximately 71.
Researchers used data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study, following participants over six years to examine the relationship between dietary sodium intake, brain ageing and cognitive health.
Sodium consumption was assessed at the beginning of the study, while cognitive performance was monitored through four follow-up assessments conducted at 18-month intervals.
The findings showed that men who consumed more sodium experienced a significantly faster decline in episodic recall, while no comparable association was found among women.
Dr Samantha Gardener, an ECU researcher involved in the study, explained that the findings provided preliminary evidence of a relationship between higher sodium intake and changes in cognitive performance.
She emphasised the need for further research to understand the nature of the association and the biological mechanisms that might explain it.
Researchers identified several possible mechanisms through which excessive sodium intake could affect brain health, including increased neuroinflammation, damage to small blood vessels and reduced blood flow to brain tissue.
Earlier research has also suggested that high-salt diets could alter the gut microbiome and contribute to inflammation in the brain, potentially affecting memory and other cognitive functions.
However, some of these findings come from animal studies and cannot be directly applied to humans.
The World Health Organisation (WHO) recommends that adults consume less than five grams of salt a day, equivalent to approximately one teaspoon or less than 2,000 milligrams of sodium.
Many people exceed this limit without realising it because significant amounts of sodium are found in processed and ready-made foods, including bread, cold cuts, cheese, sauces and fast food.
The amount of salt in individual products can vary considerably depending on their ingredients, portion sizes and preparation methods.
Eating several salt-rich foods throughout the day can therefore make it easy to exceed the recommended daily intake.
Although the Australian study found an association between higher sodium consumption and faster memory decline in older men, it does not establish that eating too much salt directly causes memory loss.
The findings have nevertheless raised further questions about sodium's potential effects on brain health, alongside its established links to high blood pressure and cardiovascular disease.
