A salty diet may do more than harm your heart and kidneys. A new study suggests it can also inflame the brain, driving up blood pressure in ways scientists hadn’t fully recognized before.
Researchers at McGill University found that when rats consumed salt levels comparable to a fast-food-heavy human diet, their brains showed an inflammatory response. Immune cells in a specific brain region became activated, which in turn boosted levels of vasopressin, a hormone that raises blood pressure.
“This is new evidence that high blood pressure can originate in the brain, opening the door for developing treatments that act on the brain,” said study author Masha Prager-Khoutorsky, associate professor in McGill’s Department of Physiology.
High blood pressure, or hypertension, affects two-thirds of people over 60 and contributes to about 10 million deaths globally each year. The condition often develops without noticeable symptoms, but it sharply increases the risk of heart disease and stroke. While most treatments focus on the kidneys and blood vessels, this study, which was published in Neuron, highlights the brain as another key player. That insight may help explain why up to one-third of patients don’t respond to current medications.
The researchers note that rats were chosen for this study because their bodies regulate salt and water more like humans than mice, making the findings more relevant. Using new brain imaging tools, the team was able to watch these changes in real time, something that wasn’t possible until recently.
Next steps include investigating whether similar brain-driven processes occur in other forms of hypertension. If so, the brain could become a promising target for future treatments, especially for people whose blood pressure resists standard drugs.
This research was supported by the Canadian Institutes of Health Research, the Heart and Stroke Foundation of Canada and the Azrieli Foundation.