Hot dogs are as American as high blood pressure. And a new study shows the former can cause the latter. Researchers from the University of Texas Southwestern discovered a diet high in phosphate additives, found in processed foods like hot dogs and lunch meats, can trigger a brain signaling pathway to overactivate the sympathetic nervous system and increase blood pressure.
The sympatheic nervous system regulates cardiovascular function and scientists believe the results of this study could lead to treatment strategies for people with hypertension as a result of overconsumption of high-phosphate foods.
"This research uncovers a previously unrecognized brain-mediated mechanism by which high dietary phosphate intake promotes hypertension and sympathetic overactivation, highlighting central fibroblast growth factor receptor signaling as a novel therapeutic target," said the study's first author, Han Kyul Kim, Ph.D., Assistant Professor of Internal Medicine in the Division of Cardiology at UT Southwestern.
Inorganic phosphate is often used as a preservative or flavor enhancer is processed meats and other packaged foods. The study found the average adult in America and in other developed countries takes in far more phosphate and the recommended daily allowance.
Excessive intake can cause circulating fibroblast growth factor-23 (FGF23) to enter the brain and trigger hypertension.
Hypertension occurs when pressure pushing against a person's arterial walls is too high. Nearly half of American adults have high blood pressure, which can increase the risk of deadly medical events like heart attack and stroke.
Researchers ran tests on rats with high-phosphate diets as well as on those that had what is considered a normal phosphate level. The measurement was also recorded during an exercise-induced stress response.
The rats on a high-phosphate diet had increased levels of FGF23 in their serum, cerebrospinal fluid and brain stem. The FGF23 protein was able to cross the blood-brain barrier which caused high blood pressure at rest and during physical stress.
"FGF23 can cross into the brain and influence the brain stem centers that control blood pressure," said senior corresponding author Wanpen Vongpatanasin, M.D., Professor of Internal Medicine at UT Southwestern and Director of the Hypertension Section in the Division of Cardiology and the Hypertension Fellowship Program.