A number of studies have shown that African Americans are more likely than Caucasians to have high blood pressure. Although genetic factors are often blamed, new research suggests that this racial gap is largely due to environmental - and potentially preventable - factors.

The new study compared the rates of high blood pressure (hypertension) between black and white subjects in different populations.

For blacks, populations in Nigeria, Jamaica and the US were studied, while for whites, populations in the US, Canada and five European countries were studied.

If racial origin played a major role in high blood pressure, then rates of the condition for each race would be expected to be about the same regardless of where people lived. Instead, the researchers found wide variation in rates, ranging from 14 percent for blacks in some geographic regions to 44 percent in other places. For whites, the rates ranged from 27 percent to 55 percent depending on where people lived.

The lowest rate of high blood pressure (13.5 percent) was among blacks living in Nigeria, while the highest (55.3 percent) was among whites in Germany.

Among blacks, rates of the condition were higher for people living in more industrialized places. For example, Nigerians had a rate of 13.5 percent, Jamaicans a rate of 28.6 percent and US blacks a rate of 44 percent.

The traditional emphasis placed on genetics to explain the large number of African Americans with high blood pressure could be distracting the healthcare community from fighting the lifestyle factors that are actually causing the condition, the study’s authors cautioned.

The authors, Dr. Richard S. Cooper from Loyola University Stritch School of Medicine in Maywood, Illinois, and colleagues, published their report in the January 5 issue of the journal BMC Medicine.

SOURCE: BMC Medicine, January 5, 2005