More Fruit, Fewer Sugary Drinks: Study Finds Links to Adolescent Mental Health

The study, published in the journal Child and Adolescent Mental Health, included 6,537 adolescents from 71 schools across Australia. At the beginning of the study, participants were approximately 13 years old on average. They regularly completed questionnaires reporting how many servings of fruit, vegetables, and sugar-sweetened beverages they consumed each day.

The researchers assessed symptoms of anxiety and depression using validated questionnaires. The outcomes reflected whether participants reached a predefined threshold for significant symptoms, rather than whether they had received a clinical diagnosis.

According to the findings, each additional daily serving of fruit was associated with a 13% lower risk of elevated depressive symptoms and a 7% lower risk of elevated anxiety symptoms. However, the association between fruit consumption and anxiety did not reach statistical significance when the data for boys and girls were analyzed separately.

By contrast, consuming sugar-sweetened beverages was associated with an increased risk of elevated symptoms of both conditions. These beverages included soft drinks, sports drinks, and other drinks with added sugar. The association was observed in adolescents of both sexes, but the estimated risk increases were higher among boys, particularly for anxiety. However, the researchers did not establish whether the difference between the sexes was statistically significant.

The authors suggested that the association between sugary drinks and mental health could be partly explained by inflammatory processes or changes in hormone levels, such as cortisol. However, these potential mechanisms were not tested in the study. The findings may also have been influenced by other dietary and lifestyle factors among the participants.