Genes for immunity forged in a germ-filled past are often blamed for making our bodies overreact to harmless triggers such as pollen or food. But evolution may not be so one-sided.
Some infection-fighting gene variants that spread over the past 10,000 years appear to reduce the risk of asthma and other allergies, not increase it, researchers report April 14 in a preprint posted to bioRxiv.org.
The finding challenges a long-standing idea that modern allergies are simply the price we pay for immune systems tuned to a dirtier past. That idea is “too simplistic,” says evolutionary geneticist Will Barrie of the University of Cambridge in England, who was not involved