According to a recent study, immigrants who have spent more of their lives in Canada are at a higher risk of developing multiple sclerosis (MS) than those who have spent less time in the country. It’s important to note that while the study shows an association, it does not prove that living in Canada for a longer period of time directly causes MS.This article is from the online version of Neurology®, which is the medical journal of the American Academy of Neurology. The research does not confirm that living a longer life in Canada causes MS, but it only indicates a connection. Study author Manav V. Vyas, MBBS, MSc, PhD, who is affiliated with St. Michael’s Hospital in Toronto, Canada and is a member of the American Academy of Neurology, mentioned that previous research has suggested that immigrants generally have better health than long-term residents, possibly because healthy individuals are more likely to immigrate. The aim was to investigate whether the decreased risk of MS diminishes over time as individuals assimilate.The research included 1.5 million immigrants who arrived in Canada between 1985 and 2003 and had health insurance for at least two years without a diagnosis of MS. They were then monitored until 2016. During this time, 934 individuals were diagnosed with MS, resulting in a rate of 0.44 cases per 100,000 person-years. This is significantly lower than the estimated rate of 15 to 17 cases per 100,000 person-years in the general Canadian population. The difference in MS rates may be due to immigrants adopting healthier lifestyles in Canada or being exposed to different environmental factors that affect their risk.The study measured the length of time each individual participated. The researchers used the individual’s age upon arrival in Canada and the years since immigrating to determine the percentage of their life spent in Canada. On average, participants had spent 20% of their lives in Canada.
The study revealed that individuals who had spent 70% of their lives in Canada were 38% more likely to develop MS compared to those who had spent only 20% of their lives in the country. This finding considered other variables that could impact the risk of MS, including gender, age, and other medical conditions.
The study did not identify any discrepancies between males and females, The study focused on Canada’s immigration classes, which include family, refugee, and economic. The data did not cover environmental factors related to MS, but it is theorized that the increased risk of MS over time may be attributed to lifestyle factors like smoking and dietary changes, environmental factors such as sunlight exposure, and biological factors like the gut microbiome composition. Vyas also mentioned that immigrants may be more vulnerable to these risk factors due to social determinants of health.”Income, education, neighborhood, and access to nutritious food.”
One potential drawback of the research is that it identified new MS cases through the healthcare system, and immigrants may have different tendencies compared to non-immigrants when it comes to seeking care for their symptoms due to cultural background, age, time spent in the country, familiarity with the language, or other factors related to the healthcare system.
The research received support from the MS Society of Canada and the Consortium of Multiple Sclerosis Centers.
