High salt intake linked to faster memory decline in one group, study finds

Excess salt intake has long been linked to higher blood pressure, but now a new study has also tied it to quicker cognitive decline in certain groups.

In a six-year study of more than 1,200 older adults 60 and older, Australian researchers found that higher baseline dietary sodium intake was associated with faster decline in "episodic recall" in men, but not in women. 

"Episodic recall is a type of memory used to recall personal experiences and specific events from one’s past, such as where you parked your car or your first day of school," according to study author Samantha Gardener, Ph.D., a research fellow in neuroscience at the School of Medical and Health Sciences at Edith Cowan University in Western Australia.

"We did not see any relationship between the amount of sodium consumed and memory decline in females," she told Fox News Digital.

The finding suggests that sodium intake may be a modifiable risk factor for memory decline in older males.

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While males did report consuming a greater amount of sodium than females, which could explain why the increased cognitive decline was only observed in males, it could also be due to their higher diastolic blood pressure, according to Gardener.

"Elevated blood pressure is a recognized risk factor for cardiovascular disease and Alzheimer’s disease, and sodium plays a key role in blood pressure regulation," she said.

The research relied on data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging. The findings were published in the Neurobiology of Aging.

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"This study adds to the evidence that high-sodium diets may affect more than blood pressure," New Jersey-based registered dietitian Erin Palinski-Wade, who was not involved in the study, told Fox News Digital. 

"These study findings are a good reminder that sodium intake matters for brain and heart health, especially for adults who already eat more than recommended."

"While excess sodium may impact cognition, it is important to note that this was a longitudinal observational study, meaning it can show an association but cannot rule out other potential factors like overall diet quality, physical activity or other comorbidities," Palinski-Wade noted.

Also, the participants reported their sodium intake via a food frequency questionnaire, which could be subject to recall error, the researchers pointed out.

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As sodium exposure was measured only at baseline, changes in intake over time were not captured by the study. It also only included sodium content in foods and beverages, and did not include salt added during cooking or at the table.

The participants were mostly Caucasian, which means the results may not apply to other populations.

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"We were not able to identify why sodium intake is having this effect, and this will be researched in the future," Gardener told Fox News Digital.  

"These findings are preliminary, and further investigation is required to evaluate how sodium intake could be incorporated as one modifiable lifestyle factor aimed at delaying Alzheimer’s disease onset."

The current Dietary Guidelines for Americans recommends less than 2,300 mg of sodium per day for adults, which is equivalent to roughly 1 teaspoon of table salt.

Typical high-sodium foods in the U.S. diet include pizza, sandwiches and burgers, deli meats, and chips, crackers and salty snacks. 

Other high-sodium foods in the grocery store include canned foods, salad dressings, deli meats, cheeses and condiments, according to Tanya Freirich, a registered dietitian and certified diabetes care and education specialist in North Carolina.

Up to 80% of sodium intake comes from processed foods, she noted.

"Replacing one processed snack – such as beef jerky, olives, salted nuts, pretzels and bagged potato or corn chips – with an unprocessed snack is a great place to start," Freirich, who also was not involved in the research, told Fox News Digital.

Healthier, unprocessed snacks include fruit, lightly salted nuts, carrots and hummus, or lower-sodium versions of chips, she said.

"Replacing a few fast food meals with food prepared at home is also an excellent way to reduce your sodium intake by thousands of milligrams," the expert advised.

Palinski-Wade echoed that the majority of sodium in the diet doesn’t come from the salt shaker, but from ultraprocessed and prepared foods. 

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"Read the labels, monitor your intake, and fill your diet with foods that promote heart health, including whole fruits and vegetables, nuts and seeds, legumes, and lean proteins," she advised.

Successfully lowering sodium intake can reduce the risk of not only high blood pressure and cognitive decline, but also kidney and cardiovascular disease, the experts agreed.