"Differences in hypertension due to acculturation status may be a result of changes in traditional lifestyles and dietary practices, including meal patterns and food choices," says lead author Mark S. Kaplan, Dr.P.H.

Asian immigrants who lived in Canada for not more than four years had a prevalence of hypertension below 3 percent compared with a prevalence greater than 7 percent among immigrants who had lived in Canada for five years to nine years. Ten or more years of residence correlated to a prevalence rate of greater than 13 percent, the researchers report.

The study included data on nearly 2,000 Asian immigrants surveyed as part of the 1996-1997 Canadian National Population Health Survey. The prevalence of hypertension in people over the age of 20 years was 10 percent across the entire survey.

The study also showed that overweight or psychologically distressed immigrants had roughly two-fold the risk of hypertension of their peers. These factors, as well as age, sex, education status, smoking and drinking status, physical activity, health status and access to health care, were controlled for in determining the effects of duration of residence on hypertension.

One weakness of the study is that hypertension rates are based on survey respondents' answers to a question about whether they had been diagnosed with the condition rather than actually taking blood pressure measurements, says Kaplan. He added that the results should be interpreted with caution.

"The relationship between acculturation and health status is a complex one," he says. "One firm conclusion that can be drawn from our study is that there is a clear pattern in the prevalence of hypertension that follows a timeline of cultural adaptation."