A Curtin University study has revealed that moving to Australia may increase hay fever and allergy symptoms in Chinese immigrants, as well as affecting their genetic make-up.
The researchers conducted two studies relating to allergy studies of Chinese immigrants arriving and living in Australia and the associated impact of Westernised life.
Senior Research Fellow, Dr Brad Zhang from Curtin’s School of Public Health, said in the first study, a total of 142 Chinese immigrants answered questionnaires relating to their allergy status and the length of time they had lived in Australia, they also underwent allergy tests.
“The research found that incidence of hay fever and levels of inflammatory molecule interleukin-10, an indication of allergy, both increased with increasing length of time in Australia. One in two Chinese immigrants had hay fever after living in Australia for a sufficient period of time,” Dr Zhang said.
“Chinese immigrants residing in Australia for at least 7.5 years were found to be more sensitised to both mixed rye grass and mixed grass than those who had been a resident for less than 7.5 years.
“Those who had lived in Australia for at least two years were more sensitised to two different species of house dust mite, indicating allergy, compared to those with less than two years of residency. The sensitisation to various allergens appeared to change with the time living in Australia.”
The second study involved analysing the DNA methylation (a naturally occurring mechanism that regulates genes) of 25 newly arrived Chinese immigrants that had lived in Australia for at least two years, compared with newly arrived Chinese immigrants. The DNA of longer-resident immigrants was found to have undergone more structural changes known as methylation, which in turn reduced the gene expression levels in these longer resident immigrants.
Dr Zhang said the research team did not know the exact influence of these epigenetic changes on human health and were conducting more studies to investigate the cause of these changes and its impaction on health, particularly in children.
“The two studies showed, in different ways, the effects that the Westernised lifestyle in Australia was having on the Chinese immigrants,” Dr Zhang said.
“Not only are they suffering high levels of hay fever and allergy the longer they have lived in Australia, but also their DNA methylation appears to be altered once they have lived here for two years or more.”