High Salt Intake Promotes Tau Phosphorylation, Leading to Cognitive Decline

A high-salt diet affects endothelial dysfunction and tau regulation in the brain, according to new research being presented at the 144th Annual Meeting of the American Neurological Association.

While it is well known that salt intake is associated with poor vascular outcomes, including stroke and dementia, it is unclear how specific processes in the brain are affected by salt.

To investigate this connection, the researchers observed tau phosphorylation, and calpain and Cdk5 activity in the brains of mice fed with a high-salt diet or a normal diet for 12 weeks.

After 12 weeks, the researchers found that a high-salt diet increased tau phosphorylation both at Ser Thr (AT8) and Thr (RZ3) in both neocortex and hippocampus, and increased the catalytic activity of both calpain and Cdk5.

However, 10 g/L of L-arginine in drinking water prevented these increases in tau phosphorylation and suppressed the activity of calpain and Cdk5 that were induced by the high-salt diet.

Cognitive impairment induced by a high-salt diet was not seen in this mouse model.

“The findings unveil a previously unrecognized link between dietary habits, endothelial dysfunction, and tau pathology, and suggest that avoiding excessive salt intake might be beneficial in maintaining both vascular and cognitive health,” the researchers concluded.

—Amanda Balbi

Reference:

Faraco G, Hochrainer K, Segarra SG, et al. Dietary salt induces cognitive impairment by promoting tau pathology. Paper presented at: 144th Annual Meeting of the American Neurological Association; October 13-15, 2019; St. Louis, MO. https://onlinelibrary.wiley.com/doi/10.1002/ana.25587.