Immigrants tend to be healthier than those born in Canada, but the "healthy immigrant" effect weakens over generations, a new study by Statistics Canada suggests.
According to the study, first-generation immigrants born outside of Canada, have lower hospitalization rates than successive generations born in the country.
“Two explanations exist for healthier new immigrants,” said clinician-researcher Joel Ray, who has conducted his own research on immigrant health in Canada.
“The first is that Canada generally accepts people into Canada through health-screening of all new Canadians who emigrate,” he said. “Then, separately, the very nature of the source countries having overall less obesity – and overall healthier lifestyles.”
Using data from the 2006 long-form census and hospital records, researchers found that recent immigrants were less likely to be hospitalized than immigrants whose families had been in the country for multiple generations.
And by the time immigrant families have been in Canada for three or more generations, the rates of hospitalization begin to "converge," the study says.
“It’s been shown that it takes about 10 years for a new immigrant to achieve the same body index as a Canadian-born Canadian” Ray said, explaining why first-generation immigrants may appear healthier.
Researchers examined three years of information from 2006 to 2009, and found that the "all-cause hospitalization rate" for first-generation immigrants was 609 per 10,000 population.
Among second-generation immigrants who were born in Canada but had at least one parent born outside the country, the rate rose to 792 hospitalizations per 10,000.
And among third-plus generation immigrants, whose parents were both born in Canada, the rate was 839 hospitalizations per 10,000.
The difference between generations was seen among both men and women.
Ray mostly attributes the decrease in health of immigrants to lifestyle choices. “It may be connected to more of a westernized lifestyle that has readily accessible high-caloric foods that in some countries may not have been available.”
The study also found a similar pattern when it looked specifically at circulatory diseases.
According to the report, the hospitalization rate for circulatory diseases among first-generation immigrants was 119 in 10,000.
Among second-generation immigrants, the rate was 142 per 10,000, and among third-generation immigrants, the rate was 152 per 10,000.
In addition to varying by generation, immigrant hospitalization rates also varied by country of origin.
For example, immigrants from South Asia had higher odds of hospitalization for circulatory problems, the study suggests, while those of Chinese descent were less likely to be hospitalized for similar issues.
Statistics Canada also notes that, based on age-standardized hospitalization rates, the health advantage in circulatory diseases among immigrants of South Asia was lost by the second generation.
Ray notes that immigrant groups may have different genetic pre-dispositions to certain health conditions, such as high blood pressure and that “some genetic pre-dispositions won’t increase once certain groups come to Canada.”
He also stresses the importance of the study and learning more about immigrant health.
“This is informative,” Ray says. “I think the idea that this sort of information and the way that it can be used really needs to be understood by the individuals it’s describing.”
