Tucking in to lots of junk food during pregnancy might help to ease those pregnancy pangs, but consumption of an unhealthy diet can pre-program unborn children’s preference for junk food in later life, warn researchers.
The new study data suggests that pregnant mothers who consume junk food may actually lead to an addiction-like response to junk food in children.
Writing in The FASEB Journal, the research team report data to suggest that a high intake of junk foods during pregnancy leads to changes in the development of the opioid signalling pathway in the brains of unborn children. This change results in the babies being less sensitive to opioids, which are released upon consumption of foods that are high in fat and sugar.
In turn, these children, born with a higher ‘tolerance’ to junk food need to eat more of it to achieve a ‘feel good’ response, they suggest.
"The results of this research will ultimately allow us to better inform pregnant women about the lasting effect their diet has on the development of their child's lifelong good preferences and risk of metabolic disease," said Dr Beverly Muhlhausler from The University of Adelaide in Adelaide, Australia – a researcher involved in the study.
"This study shows that addiction to junk food is true addiction," commented Gerald Weissmann, M.D., who is editor-in-chief of The FASEB Journal.
"Junk food engages the same body chemistry as opium, morphine or heroin,” he explained. “Sad to say, junk food during pregnancy turns the kids into junk food junkies."
"Hopefully, this will encourage mothers to make healthier diet choices which will lead to healthier children," said Muhlhausler.
Muhlausler and colleagues studied the pups of two groups of rats, one of which had been fed a normal rat food and the other which had been fed a range of human "junk foods" during pregnancy and lactation.
After weaning, the pups were given daily injections of an opioid receptor blocker - which blocks opioid signalling and therefore lowers the intake of fat and sugar by preventing the release of dopamine.
However the team found that the opioid receptor blocker was less effective at reducing fat and sugar intake in the pups of the junk food fed mothers, suggesting that the opioid signaling pathway in these offspring is less sensitive than for pups whose mothers are eating a standard rat feed.
The team concluded that their research shows that eating a junk food diet during pregnancy changes the development of the opioid signalling pathway in the baby's brain. This results in decreased sensitivity and therefore means children need to eat more junk food in order to attain a 'feel good' response.