Unhealthy lifestyles associated with social deprivation may have detrimental effects on DNA before birth, say scientists. A study of adults living in Glasgow shows a correlation between deprivation and DNA methylation - a normal process that occurs mainly during embryonic development and regulates gene activity. Researchers suggest these differences in methylation may affect an individual's risk of developing disease later in life.
Professor Carol Tannahill, director of the Glasgow Centre for Population Health, which funded the study, said that the 'findings add evidence that people in poorer socio-economic circumstances may face an uphill health challenge from before birth'.
A team from the University of Glasgow analysed the DNA of 239 adults living in both impoverished and affluent areas of the city. The team work in the field of epigenetics - the study of factors that alter genes without changing the DNA sequence itself. This includes environmental factors which modify DNA through chemical changes like methylation.
In DNA methylation enzymes in the cell tag parts of the DNA to indicate that a certain gene should be turned on or off at a specific time and place. Such tags are largely set during the first stage of human embryonic development and are required throughout life to ensure the correct development and continued function of tissues and organs. In this study the DNA of people from deprived areas showed low levels of methylation.
Dr Paul Shiels, the epigeneticist who led the study, explained: 'Methylation levels decline throughout everyone's life as part of the natural process of ageing and can be slightly affected in adulthood by external factors such as diet, stress and lifestyle. Those external factors have a much greater effect on babies developing in the womb [...] so it's very likely that the significantly lower levels of methylation we're seeing in the most deprived areas of the city are set before birth'.
A direct relationship between social deprivation and genetic predisposition to ill health has not been firmly established by this study, though a correlation is suggested. Further investigation is therefore needed to determine the genetic impact on the offspring of expectant mothers living in deprived areas.
This study was published in the International Journal of Epidemiology.
