Disturbing discovery: The basic ingredient that may impair men's memory

In a study published in the scientific journal "Neurobiology of Aging", which lasted for six years and included careful monitoring of older adults, researchers discovered that men who consume high amounts of sodium suffer from accelerated memory impairment compared to those who maintained a low dosage.

A team of scientists led by Dr. Samantha Gardner from Edith Cowan University monitored 1,208 participants with an average age of 71. The researchers estimated the amount of sodium consumed by each participant and performed memory and thinking tests every year and a half throughout the follow-up period.

The data showed that men who consumed the highest amounts of sodium experienced a sharp and significant decline in "episodic memory" performance — the brain mechanism responsible for the ability to recall personal experiences and specific events from the past. Surprisingly, in women, no link was found between salt consumption and impairment of memory ability.

The researchers emphasized that this is an observational study that points to a clear statistical link, but does not constitute absolute proof of a cause-and-effect relationship. The exact reason for the difference between the sexes is still unknown, and it is estimated that it may be due to biological differences in the structure of blood vessels, the effect of hormones on fluid and salt retention, or different reports on eating habits.

According to World Health Organization guidelines, it is recommended that adults limit daily sodium intake to less than 2,000 milligrams — an amount equal to about five grams of table salt (about one teaspoon in total).

Despite this, in the Western diet, more than 70% of sodium amounts come directly from processed and industrial foods, including store-bought bread, sausages and processed meats, hard cheeses, and ready-made meals, and not necessarily from the salt added during cooking or eating.

Excess sodium in the body causes an increase in blood pressure, hardens blood vessels, and may reduce normal blood flow to brain tissues. Previous laboratory experiments on animals have demonstrated that a high-salt diet triggers inflammation in the nervous system, damages tiny blood vessels in the brain, and even disrupts the composition of gut bacteria in a way that leads to direct impairment of spatial memory.

The study's findings serve as a significant reminder of the impact that processed food has on brain functions throughout the aging process. Along with this, the scientists emphasize that additional controlled clinical trials will be required to finally confirm whether a proactive reduction of salt in the daily menu indeed directly protects memory and slows cognitive decline with age.