- A new study looks at how salt intake impacts brain health.
- One group in particular appeared to be significantly affected.
- Here’s how salt intake may impact cognition over time, and how to keep your intake in check.
As much as scientists are looking into foods that improve brain health, they’re also spending time parsing out what may not be good for it. That brings us to the findings of a new study that looked at how salt intake affected a group of men and women’s cognition over a six-year period.
Meet the Experts: Jennifer Pallian, B.S.C., R.D., a registered dietitian and food scientist; Lauri Wright, R.D.N., dietitian and associate professor at the University of South Florida College of Public Health; and Alexander Zubkov, M.D., a board-certified neurologist at Minneapolis Clinic of Neurology.
The observational data shook out to this: Men with high salt intake appeared to experience more damage to their memories than women did. Below, a neurologist and dietitian weigh in and share how exactly sodium—an ingredient that is globally over-consumed and carries a wide-sweeping health burden, according to the World Health Organization (WHO)—impacts the brain.
How was the study conducted?
The study, published in Neurobiology of Aging, followed over 1,200 cognitively normal, older, mostly caucasian Australian adults for six years and tracked how their usual salt intake related to changes in their thinking and memory. To do so, participants took a food questionnaire (which did not note extra salt used at the table or during cooking) and participated in neuropsychological testing every 18 months, which looked at their episodic recall (memory of specific events), attention, language, executive function, and other symptoms related to the early development of Alzheimer’s disease.
As we mentioned, there wasn’t a clear link made between higher salt intake and overall cognitive decline in the whole group. The significant association appeared when the male cohort was examined. Specifically, older men with higher salt intake experienced a decline in their episodic recall abilities.
“Episodic recall is particularly important because it is one of the earliest cognitive domains affected in Alzheimer’s disease, and is closely linked to hippocampal function,” says Jennifer Pallian, B.S.C., R.D., a registered dietitian and food scientist. (The hippocampus is the memory center of the brain.) It’s worth reiterating, however, that the findings were observational, meaning that they cannot prove that salt directly causes memory decline.
How salt may affect memory over time
We already know that high salt intake is associated with high blood pressure, which poses cardiovascular health risks. These findings could give people more reason not to go for an extra shake or pinch.
In fact, Pallian and Lauri Wright, R.D.N., dietitian and associate professor at the University of South Florida College of Public Health note that the vascular health implications of a high sodium diet alone can influence brain aging and cognition. High blood pressure can damage brain blood vessels and increase inflammation, which impairs memory pathways and may also contribute to the accumulation of a damaging protein called amyloid, which is a well-known hallmark of Alzheimer’s disease, notes Wright.
There is also growing evidence that excess sodium can impair the brain’s networks of cells and tiny blood vessels, reducing blood flow, especially in vulnerable regions like the hippocampus, which supports episodic memory, adds Alexander Zubkov, M.D., a board-certified neurologist at Minneapolis Clinic of Neurology. Over time, those changes can show up as small declines in memory performance, he adds.
Even though both men and women study participants ate a lot of salt, the men ate more and had higher diastolic blood pressure, “so they likely bore a larger cumulative vascular and inflammatory burden from salt,” Dr. Zubkov notes. “It may be that only men crossed a threshold where the cognitive impact became measurable over six years.”
How to reduce your salt intake
Sodium intake is increasing in Americans largely due to its widespread presence across the food supply and its heavy use in ultra-processed foods, explains Pallian, which can make it difficult to cut back, but you can try by focusing on fresh, minimally processed foods, limiting packaged foods, using herbs and spices instead of salt for flavor, and choosing lower-sodium products by reading nutrition labels, she notes. The WHO recommends adults keep their intake to less than 2000 milligrams per day.
The bottom line
“When you put these findings together with what we already know about salt, blood pressure, and vascular brain injury, it strengthens the case for keeping sodium intake on the lower side as part of a comprehensive brain-protective lifestyle—especially for older men,” says Pallian.
Dr. Zubkov agrees that the findings are “consistent with the broader story that vascular risk factors and dietary patterns—like excess sodium—can quietly shape brain aging long before dementia appears.”
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