Early life sugar exposure linked to higher adult anxiety risk

Exposure to sugar in the first 1,000 days of a child's life increases the risk of developing anxiety in adulthood, a new study from the University of Surrey reports. Scientists also found that sugar intake in early life can impact brain development with significant differences identified in 11 out of the 80 regions of the brain.

During this unique study, scientists from Surrey investigated how exposure to sugar in early life influences a person's mental health in adulthood, dietary behaviours and neurodevelopment. It was found that the risk of developing anxiety was lowest in those who were not majorly exposed to sugar in utero and during the first two years of life.

Dr Hana Navratilova from IPB University, Indonesia who led the on the work when she was at the University of Surrey, said:

"Research has shown that sugar exposure during the first 1000 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."

To learn more, the team analysed the medical data of over 45,000 UK Biobank participants, born between 1951 and 1956, when post-war sugar rationing was still fully in place, through to when it was phased out. Participants were then divided into groups of those who experienced sugar rationing in‑utero and then up to six, 12, 18 and 24 months of age, and those who underwent rationing in utero only. A control data group of similarly aged participants born when no rationing in the UK was in place, and a further group of children born in Ireland were also analysed.

Dr Navratilova found that women in particular, who did not experience/ or experienced rationing for a limited time, were more likely to develop anxiety.

An association between early sugar exposure and depression was also identified but reduced in significance after statistical adjustment suggesting that this condition may be influenced by diet later in adulthood.

As part of the study, scientists also examined brain imaging data alongside rationing exposure. It was found that 80 of the 139 brain regions of grey matter volume were significantly different among the different rationing groups. Further analysis revealed significant differences in 11 out the 80 brain regions between most of the rationing groups and those who were never rationed (for example, regions of cerebellum).

It was also found that those who were not exposed to sugar for the longest time (in utero and up to 24 months of age) also reported a lower preference for sweet food in adulthood. Scientists uncovered some differences in preferences for sweet foods between the rationed groups and those who had never experienced rationing, indicating that sugar exposure could lead to possible long-term dietary influences.

Professor Nophar Geifman, Professor of Health and Biomedical Informatics at the University of Surrey and senior author, concluded:

"The UK Biobank is a treasure trove of data that allowed us to look at this post war 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.

"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."

This study was published in the journal Translational Psychiatry.