Immigrants' health declines the longer in Canada: study
TORONTO - The longer immigrants reside in Canada, the greater their risk of
developing cardiovascular disease -- and that effect is most pronounced among
people of Chinese origin, a study suggests.
Doctors have long known that the longer people stay after immigrating to
western countries like Canada, the less healthy they become, said principal
investigator Maria Chiu, a doctoral fellow at the Institute for Clinical
Evaluative Sciences.
"What we did not know was whether the degree to which this change happened
was different for ethnic groups that lived in Canada."
Using population and health data, Chiu and her co-authors looked at the
prevalence of risk factors for heart disease and stroke among immigrants who
had lived in Ontario for 15 years or longer, compared to those who had resided
in the province for less than 15 years.
They found that longer-term residents exhibited increased risk factors for
cardiovascular disease -- among them Type 2 diabetes, obesity, smoking and high
blood pressure -- compared with more recent ethnically matched immigrants.
"And it didn't matter whether you were white, Chinese, South Asian or
black, this trend was seen across all the major ethnic groups living in
Canada," Chiu said Monday. "We also noticed that the degree to which
cardiovascular health declined was different across different ethnic
groups."
Canadians of Chinese descent showed the worst decline in heart health over
time, she said, followed by whites, blacks and South Asians.
Diabetes appears to be the primary reason: the disease was almost twice as
common among long-term residents of Chinese and Caucasian descent than among
more recent immigrants of the same ethnic backgrounds.
"This is likely driven by higher rates of obesity in these
groups," said Chiu, noting that those living in Canada for 15 years or
more had a 30 to 40 per cent higher obesity rate compared to their shorter-stay
counterparts.
"Chinese are gaining more weight and developing more diabetes the
longer they live here, more than any other ethnic group," she said.
"It's no secret that the western diet is not the healthiest, and it's been
found that the longer people stay in the western culture, the more likely they
are to pick up bad habits, such as eating more frequently at fast-food
restaurants, eating food high in fat and added sugars, and eating between
meals.
"These bad habits are likely picked up by all the ethnic groups, but
our study suggests that the Chinese and white groups are likely to adopt these
bad habits to a greater degree than the other groups."
The study, published Tuesday in the Canadian Journal of Cardiology, also
found smoking was a prominent risk factor for blacks and South Asians who had
been in Canada 15 years or more -- and the difference was most evident among
females.
"So South Asian and black females who were born in Canada or lived in
Canada for at least 15 years were three to four times more likely to smoke than
their recent immigrant counterparts," said Chiu, calling it a surprising
finding since Ontario and the rest of the country have strict anti-smoking
laws.
"We would have expected a decrease. But obviously there is
vulnerability in the female population of people of South Asian and black
descent that we really need to target our anti-smoking messages to, a little
more effectively."
Higher psychosocial stress was also found among South Asian females who had
been in the country at least 15 years, and although the researchers don't know
the reasons behind it, stress rates correlated with increased tobacco use
within this group.
While having a different genetic makeup can explain in part why some
ethnicities are more prone to certain diseases, environment is also known to
play a role. The question for researchers has long been which is it: one or the
other or a combination of both?
"What makes this study interesting is that we compared similar genetic
makeup, meaning Chinese versus Chinese who lived here longer versus those who
were recent immigrants and we looked at how they differed," Chiu said.
"So you're looking at people with similar genetic makeup and the only
thing that's different between them is how long they've stayed here in a
western culture.
"So this study further emphasizes that we can't blame all the risks of
cardiovascular disease on genetics. We can't use that excuse that, 'Oh, we have
bad genes, we can't help but get heart disease."'
She said the findings suggest that better strategies are needed to educate
immigrants about trying to avoid adopting unhealthy dietary and other lifestyle
habits in their new country that put them at an elevated risk of potentially
deadly heart disease and stroke.
"Prevention is better than cure ... we need to protect the health of
new immigrants from the get-go."
Some organizations, including the Heart and Stroke Foundation, have launched
initiatives aimed specifically at ethnic populations.
"Having a better understanding of how length of time living in Canada
impacts cardiovascular risk factors will help us to develop tailored prevention
strategies to ensure the long-term heart health of all Canadians," said
Vincent Bowman, director of research for the foundation's Ontario division.
Such programs are critical now -- more than 250,000 immigrants settle in
Canada each year -- and for the country's future, said Chiu.
"Immigrants represent a large and growing segment of our Canadian
population and we know that by 2031, immigrants are going to be responsible for
the net growth of the Canadian population. So there's a need to better
understand how we can preserve the healthy lifestyles of people who recently
immigrate to Canada and how we can reduce the negative influences for the
future."
