by Frederick H. Lowe
Thirty to thirty-seven percent of African Americans, most of them men, retain abnormally high levels of salt in their bodies, even while they sleep, as a result of daily stress.
The salt, about 160 milligrams, a teaspoon, or what is contained in a small bag of French fries, keeps systolic blood pressure higher than a healthy 120 for individuals known as salt retainers, Dr. Gregory Harshfield, hypertension researcher at the Institute of Public Health and Prevention at Georgia Health Sciences University, tells The NorthStar News & Analysis. The retention damages their vital organs, including blood vessels, the heart and kidneys.
Individuals consume 2,000 to 2,500 milligrams of salt daily through normal eating. However, stress causes an increase in the salt load for some individuals, which they retain long after the stress-inducing incident has passed. That stress can come, for example, from being yelled at by a boss or from seeing women securing their purses when they see a black man approaching.
Normally, a person can relieve the stress by getting up from his desk and taking a brief walk. But for a large percentage of African Americans, walking does not relieve the salt load, Harshfield said.
“The worst news is that the increased retention likely causes blood pressures to stay elevated even during sleep, which should be a recuperative time for the body,” Harshfield said. “Nighttime blood pressures are considered the truest reading since they are not affected by stress.”
He believes, but does not have any scientific evidence to support his theory, that African Americans retain a large salt load due in part to obesity. A large percentage of the adult population in the United States is obese, and African Americans tip the obesity scales at much higher levels than any other groups.
Dr. Harshfield reached his conclusions following a study of blacks and stress. He released his findings in early September during the Behavioural Economics, Hypertension Session of the Psychogenic Cardiovascular Disease Conference in Prato, Italy.
Harshfield now wants to develop a method of identifying salt retainers so he or others can work with these individuals’ physicians to treat their hypertension more effectively.