April 22, 2026 | Sodium plays an important role in many physiological functions, but excessive intake leads to an increased risk of cardiovascular disease and high blood pressure. Emerging research has also shown a strong association with nerve inflammation, endothelial dysfunction, and poor blood supply to the brain. In particular, high blood pressure can be a risk factor for Alzheimer’s disease.
Women are generally more likely to develop Alzheimer’s disease due to longevity, socioeconomic factors (lack of access to health care services and education), low estrogen after menopause, and genetic factors. But what about sodium intake? The effect of sodium on cognitive decline has not yet been properly observed.
Researchers from Edith Cowan University in Western Australia investigated the relationship between dietary sodium and cognitive decline over a period of 72 months. Their findings were published in Neurobiology of aging (DOI: 10.1016/j.neurobiolaging.2026.02.003).
High blood pressure and cognitive decline
There were 498 male participants and 710 female participants, bringing the total sample size to 1208. Participants were 60 years of age or older and did not have cognitive impairment. Those with a history of bipolar disorder, schizophrenia, Alzheimer’s disease dementia, recent cancer (excluding basal cell carcinoma), Parkinson’s disease, insulin-dependent diabetes, symptomatic stroke, uncontrolled diabetes, and excessive alcohol consumption were excluded from the study. Notably, most of the group was of Caucasian descent, and it is unknown how the association between sodium intake and cognitive decline may affect other populations.
Participants were assessed at baseline and four additional time points that were spaced 18 months apart. The assessment included six cognitive domains: episodic recall, recognition, executive function, language, attention, AUS, biomarkers, and the preclinical Alzheimer’s disease cognitive composite. Participants will report how often they consume a standard size serving of each food item. Sodium intake was calculated by multiplying the reported frequency of consumption of each food item by its corresponding sodium content and adding all items to obtain total daily sodium intake. Additional salt that may be added before or during eating or during cooking was excluded from the estimates.
The results found that there was a faster decline in episodic recall in male participants over 72 months. No associations were found in female participants. High salt intake leads to high blood pressure, a known risk for cardiovascular disease and cognitive decline due to the damage it causes to blood vessels throughout the body. Over time, constant pressure causes blood vessel remodeling, weak blood vessels, and decreased blood flow, including to the brain.
Other mechanisms that may explain the observed association with episodic memory include the possibility that high salt intake leads to region-specific neuroinflammation and oxidative stress, especially within limbic structures essential for memory processing. Specifically, it may affect the hippocampus, which is responsible for memory formation, including episodic memory. Because of its high synaptic plasticity, dense microvascular network, and sensitivity to oxidative damage, the hippocampus is particularly vulnerable to inflammation and metabolic stress.
Sensitivity analyzes that adjusted for systolic and diastolic blood pressure—separately and jointly—did not substantially change the observed associations between sodium intake and cognitive outcomes. This suggests that although blood pressure may partly contribute to the observed gender differences, it does not fully account for the relationship between higher salt intake and poorer cognitive performance in males.
Dr Samantha Gardner, a research associate at Edith Cowan University, said: “More research is certainly needed into gender-specific approaches and how to incorporate sodium intake as a modifiable lifestyle factor aimed at delaying the onset of Alzheimer’s disease.” In a press release.
The researchers also wrote that higher sodium intake, associated with decreased recall of events over time, was only found among participants with normal blood pressure and low levels of sodium intake. This pattern suggests that susceptibility to sodium-related cognitive changes may vary depending on the individual’s underlying vascular status. More research is needed to confirm whether the effects of sodium intake on cognition truly vary across vascular risk levels.
Great potential for exploration
The primary limitation of the study is the self-reported measures of the participants, which leaves the opportunity for miscalculation. Another limitation to consider is that participants who remained at all assessments would have had greater chances of not experiencing cognitive impairment. Conversely, self-monitoring individuals could have noticed cognitive decline and chosen to drop out of the study, perhaps to avoid facing a potential diagnosis. As such, the study may not be representative of people with cognitive decline.
Results show promise in the relationship between sodium intake and cognitive impairment. According to the gardenerHowever, future studies will be “crucial to determine the underlying mechanisms and provide future dietary recommendations aimed at reducing dementia risk.”
