A study of twins conducted by Stanford University School of Medicine investigators shows that our environment, more than our heredity, plays the starring role in determining the state of our immune system, the body’s primary defence against disease. This is especially true as we age, the study indicates.
Much has been made of the role genes play in human health. Stunning advances in gene-sequencing technologies, in concert with their plummeting costs, have turned many scientists’ attention to minute variations in the genome – the entire toolbox of genes carried in virtually every cell in the body – in the hope of predicting people’s future health. Such studies have revealed a genetic contribution to health outcomes. But, with some notable exceptions, very few individual genetic variants contribute much to particular health conditions.
"The idea in some circles has been that if you sequence someone’s genome, you can tell what diseases they’re going have 50 years later," said Dr Mark Davis, professor of microbiology and director of Stanford’s Institute for Immunity, Transplantation and Infection. But while genomic variation clearly plays a key role in some diseases, he said, the immune system has to be tremendously adaptable in order to cope with unpredictable episodes of infection, injury and tumour formation.
"The immune system has to think on its feet," said Davis, senior author of the study.
[link url="http://med.stanford.edu/news/all-news/2015/01/environment-not-genes-plays-starring-role-in-immune-variation.html"]Stanford University School of Medicine press release[/link]
[link url="http://www.cell.com/cell/abstract/S0092-8674(14)01590-6"]Cell abstract[/link]