By University of Surrey
Exposure to higher levels of sugar during the first 1,000 days of life may be associated with an increased risk of anxiety in adulthood, according to a new study from the University of Surrey.
Researchers also found that early-life sugar exposure may have lasting effects on brain development. Differences were identified in several areas of the brain among people who experienced varying periods of sugar rationing early in life.
Researchers investigated how sugar exposure during early life was associated with mental health in adulthood, dietary behaviors and neurodevelopment. The findings suggest that the risk of developing anxiety was lowest among people who experienced sugar rationing in utero and during the first two years of life.
Dr. Hana Navratilova of IPB University in Indonesia, who led the work while at the University of Surrey, said, “Research has shown that sugar exposure during the first 1,000 days of life may influence the risk of suffering from several chronic diseases, such as diabetes. Because we’ve seen in our previous work links between the liking of sugary foods and mental health issues, we were specifically interested in understanding if having sugar in early life could contribute to incidences of mental health issues such as depression and anxiety later in life.”
“Knowing the full impact that sugar can have on our physical and mental health, across our lifespan, could help inform public health policy and reshape our diets,” she added.
A Natural Experiment From Postwar Sugar Rationing
To examine the relationship, researchers analyzed medical data from more than 45,000 UK Biobank participants born between 1951 and 1956, spanning a period when postwar sugar rationing remained in place in the United Kingdom and its subsequent phaseout.
Participants were divided into groups based on how long they experienced sugar rationing, including exposure in utero and through the first six, 12, 18 or 24 months of life. Another group experienced rationing only in utero. Researchers also analyzed a control group of similarly aged participants born when sugar rationing was not in place in the United Kingdom, as well as a group born in Ireland.
Researchers found that women who did not experience sugar rationing, or experienced it for a shorter period, were more likely to develop anxiety.
An association between early sugar exposure and depression was also identified. However, the relationship became less significant after statistical adjustments, suggesting that depression risk may also be influenced by dietary habits later in adulthood.
Lasting Effects on the Brain and Sweet Preferences
The research team also examined brain imaging data in relation to participants’ early exposure to sugar rationing. Of 139 brain regions examined for gray matter volume, 80 showed significant differences among the rationing groups. Further analysis identified significant differences in 11 of those regions when most rationing groups were compared with participants who had never experienced rationing. The differences included regions of the cerebellum.
Researchers also found that participants who experienced sugar rationing for the longest period – from in utero through 24 months of age – reported a lower preference for sweet foods in adulthood. Differences in preferences for sweet foods among the rationing groups and those who never experienced rationing suggest that early sugar exposure may have long-term dietary influences.
Professor Nophar Geifman, professor of health and biomedical informatics at the University of Surrey and senior author of the study, said the historic circumstances surrounding sugar rationing provided researchers with a rare opportunity to investigate the potential long-term effects of early nutrition.
“The UK Biobank is a treasure trove of data that allowed us to look at this postwar diet rationing, giving us unique insight into the impact of sugar exposure on our mental health. It is highly unlikely that this sort of dataset would exist again, whereby so many people did not have excess sugar in their diets and then had it slowly phased in over a prolonged period of time,” Geifman said.
“What we have found is that rationing of sugar in early life is linked to reduced sweet liking and lower risk of anxiety. Despite increased sugar consumption after rationing amongst participants, early nutritional environments appear to have lasting relevance for mental health,” she said.
The study was published in the journal Translational Psychiatry.
