The study, published in The American Journal of Psychiatry, adds to increasing evidence that many subsequent diseases in life take root before and shortly after birth.
Robert Yolken, M.D., a neurovirologist at Johns Hopkins Children's Center explained:
"Lifestyle and genes are not the only factors that shape disease risk, and factors and exposures before, during and after birth can help pre-program much of our adult health.
Our study is an illustrative example suggesting that a dietary sensitivity before birth could be a catalyst in the development of schizophrenia or a similar condition 25 years later."
According to the researchers, this is the first study to show that maternal food sensitivity may cause disorders like schizophrenia to develop in their offspring later in life. Although the team found a strong association, they caution that this does not mean that gluten sensitivity will invariably cause schizophrenia.
Håkan Karlsson, M.D., Ph.D., a neuroscientist at Karolinska Institutet and former neuro-virology fellow at Johns Hopkins, said:
"Our research not only underscores the importance of maternal nutrition during pregnancy and its lifelong effects on the offspring, but also suggests one potential cheap and easy way to reduce risk is we were to find further proof that gluten sensitivity exacerbates or drives up schizophrenia risk."
After examining 764 birth records and neonatal blood samples of Swedish children born between 1975 and 1985, the researchers found that around 211 of them developed non-affective psychoses, such as schizophrenia and delusional disorders later in life.
The team used stored neonatal blood samples in order to measure levels of IgG antibodies to milk and wheat. They found that children born to mothers with abnormally high levels of antibodies to the wheat protein gluten were nearly 50% more likely to develop schizophrenia later in life than children born to mothers with normal levels of gluten antibodies.
Even after the team took into account other factors known to increase the risk of developing schizophrenia, such as gestational age, maternal age, mothers' immigration status and mode of delivery, they found that the association remained. However, children born to mothers with abnormally high levels of antibodies to milk protein were not at increased risk for psychiatric disorders.
The suspicion that psychiatric disorders stem from maternal food sensitivity arose during World War II by U.S. Army Researcher F. Curtis Dohan, M.D. According to Dohan, food scarcity in post-war Europe and diets lacking wheat results in considerably less hospitalizations for schizophrenia. Although the association was only observational, it has piqued the curiosity of researchers ever since.
In addition, prior studies have found that individuals with schizophrenia are significantly more likely to develop celiac disease. Even though gluten sensitivity is a hallmark of celiac disease, it is not enough to diagnose the condition.