The longer a south Asian immigrant spends in a western country, the more likely he or she is to develop high blood pressure, a study finds.

The research provides more evidence that the shift towards a western lifestyle is damaging to health.

Canadian scientists looked at the health records of almost 2,000 Asian immigrants.

In total, one in ten of them was found to have high blood pressure.

This can be dangerous as it increases the risk of heart disease and stroke.

Long stay problems

However, those immigrants who had only been in the country for a few years were far less likely to have high blood pressure.

Only 3% of this group reported the problem

Those settled in the west for between five and nine years had an increased risk - 7% of the group had hypertension.

Finally, 13% of those resident in Canada for 10 or more years had high blood pressure.

UK evidence

Dr Mark Kaplan, from the School of Community Health at Portland University, who led the study, said: "It may be a result of changes in traditional lifestyles and dietary practices, including meal patterns and food choices.

"The relationship between acculturation and health status is a complex one.

"One firm conclusion that can be drawn is that there is a clear pattern in the prevalence of hypertension that follows a timeline of cultural adaptation."

There is clear evidence in the UK that south Asians are more prone to heart disease than Caucasians.

Early deaths from coronary heart disease among Indians, Bangladeshis, Pakistanis and Sri Lankans are around 50% higher than the UK average.

A British scientist said that, while the situation in Canada might be different, south Asians arriving in the UK tended to maintain a similar diet rather than fully embrace western foods.

Dr Janet Cade, from the Nuffield Institute for Health said: "It is possible that their lifestyle is less active in the UK, which makes them more prone to weight gain.

"So it may not simply be that western diets are less healthy."

The study was published in the Journal of Epidemiology and Community Health.