The toll of racism? - The stress of discrimination, real or perceived, may be shortening black men's lives.

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 for his future, and those 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 males 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. Those are all good things when it comes to fleeing a wild beast or a suspicious sound in a dark parking lot. But for many African Americans, these responses may occur so frequently that they eventually result in a breakdown of the physiological system.