Terry Davis didn't know he was having a stroke, much less that, as an African-American male, he had a three to four times greater risk of suffering one than a white man. When a transient ischemic attack, or ministroke, hit nearly a year ago, he was 49. He woke up early, felt a little slackness on his right side, a little slowness in his speech. A professional tennis teacher, he canceled the day's lessons and, thinking more sleep was what he needed, went back to bed.
His wife, Carrie, still feels guilty that she got a little annoyed with his lethargy that day. "I thought, 'Snap out of it. Help me get the kids going,'" she says.
Davis is fine now. But the stroke scared him about his future, and the futures of his four sons, ages 8, 16, 18 and 21. These days, they all keep a more watchful eye on one another's health habits.
Statistically, black men in America are at increased risk for just about every health problem known. African-Americans have a shorter life expectancy than any other racial group in America except Native Americans, and black men fare even worse than black women. Some of it can be chalked up to poverty, the most powerful determinant of health, or to lifestyle factors. But even when all those factors are accounted for in studies, the gap stubbornly persists. Now researchers are beginning to examine discrimination itself. Racism, more than race, may be cutting black men down before their time.
It is possible, they believe, that the ill health and premature deaths can be laid -- at least in part -- at the feet of continuous assaults of discrimination, real or perceived.
"We have always thought of race-based discrimination as producing a kind of attitude," says Vickie Mays, psychologist and director of the UCLA Center on Research, Education, Training and Strategic Communication on Minority Health Disparities. "Now we think we have sufficient information to say that it's more than just affecting your attitude. A person experiences it, has a response, and the response brings about a physiological reaction."
The reaction contributes to a chain of biological events known as the stress response, which can put people at higher risk of cardiovascular disease, diabetes and infectious disease, says Namdi Barnes, a researcher with the UCLA center.
That protective response includes the release of cortisol, often called the stress hormone. It increases blood pressure and blood sugar levels and suppresses the immune system. For many African-Americans, these responses may occur so frequently that they eventually result in a breakdown of the physiological system.
"This whole phenomenon of cumulative biologic stress is real," says Nicole Lurie, director of the Rand Center for Population Health and Health Disparities.
The shorter life expectancy of black men has been an inflexible truth since slavery. The gap has slowly narrowed throughout the last century, and the most recent improvement is attributed to lower accident and homicide rates, along with life-sustaining treatments for AIDS, all of which afflict a greater proportion of black men.
Still, heart disease, stroke, hypertension, diabetes, obesity and most cancers strike black men sooner, and cut them down more often, than white men. And the higher incidence of disease among black men is set against a backdrop of an increased incidence of poverty, which carries with it a multitude of health problems. Poor people smoke more, exercise less and are more likely to be victims of accidents and violence.
It adds up to an average life span for black men that is 6.2 years less than for white men, and 8.3 less than the national average, 77.8 years, for all races and both genders.
"There's a whole boatload of things that are in the environments where they're more likely to grow up," Lurie says. "HIV, crime, that kind of stuff. There's a lot of extra dying going on from trauma."
Still, all the socioeconomic factors together don't fully explain racial disparities.
In a Feb. 9, 1990, study in the Journal of the American Medical Association, researchers compared black and white death rates per 100,000 people 35 to 54 years old and found the black rate 2.3 times higher. When they adjusted the data for known risk factors such as smoking, alcohol intake and diabetes, the gap narrowed to 1.9 times, and when they adjusted further for income, it narrowed to 1.4 times.
How people live, die and get sick depends on economic class as well as race, but all of the adjustments combined didn't completely explain the black-white mortality gap, leaving about a third of the problem unexplained, the researchers found.
"Life expectancy for everyone is increasing, but the disparities are not getting better," Lurie says.
Seeking to explain that gap, researchers have grown increasingly interested in the theory, based on a growing body of evidence linking stress to poor physical health, that racial discrimination can result in unremitting stress. That additional, continuing stress might explain some of the still mysterious gap.
UCLA's Mays was lead author on a paper published in the 2007 Annual Review of Psychology that examined studies looking at the responses of the brain and body to race-based discrimination. Experiences of racial discrimination can set the brain up for what's known as the fight-or-flight response. If it happens over and over again, in large doses of vulgar taunts or small doses of perceived slights, parts of the brain become overwhelmed.
"Let's say something occurs where [security follows] me around in a store," Mays says. "I think that's racist. My blood pressure goes up. I get upset. Then I go to a different store. Someone appears to start following me. I am primed from a previous experience and I feel it again. We call it a micro-assault."
According to research into stress, such emotionally packed memories are held in a part of the brain called the amygdala, which regulates fear responses through the release of hormones such as cortisol.
At first, the release of cortisol acts as an anti-inflammatory agent in the body. But if the body continually overloads with the hormone, the protective system shuts down and then actually reverses, increasing inflammation, which is linked to high blood pressure, cardiovascular disease and possibly diabetes.
Mays believes, and argued in the recent paper, that scientists know enough about people's reactions to racial discrimination and also the body's response to stress to link the two. "The literature is building," she says.
Studies keep pouring out showing racial disparities in health. A recent one in the September 2007 Annals of Epidemiology found that even in the so-called stroke belt of Southern states, where all races and both genders suffer the highest rates of stroke in the country, African-American men are stricken at the highest of the high rates.
The study's lead author, Dr. George Howard, chairman of the department of biostatistics at the University of Alabama at Birmingham, is not ready to finger discrimination as the primary cause. "It's a whole toxic cocktail of bad things, but if I had to pick one, it would be socioeconomic status," he says. "It's clear that racism plays a role, but I don't think it's the 800-pound gorilla."
Susan Brink writes for the Los Angeles Times.