Each Extra Daily Serving of Fruit Was Linked to 13 Percent Lower Risk of Teen Depression Symptoms
Sydney researchers followed 6,537 school students for years. Fruit tracked with fewer symptoms and sugary drinks with more, but the authors warn this does not prove cause.
Outspoken Digest Nutrition Desk
Wednesday, October 21, 2026/2 min read
An apple a day will not cure a teenager's low mood, and the scientists behind a new Australian study are the first to say so. What they did find, after following more than 6,500 students through high school, is a pattern worth noticing: the more fruit teenagers ate, the less likely they were to develop symptoms of depression and anxiety later on.
The research, from the University of Sydney's Matilda Centre, appeared in the journal Child and Adolescent Mental Health, the university said on 19 October.
What did the study measure?
The team used data from the Health4Life study: 6,537 students at 71 secondary schools in New South Wales, Queensland and Western Australia, who were about 12.5 years old at the start. They completed surveys each year through high school. The university's account gives the follow-up as both three and four years in different places, so the exact length is unclear.
Students who already met the threshold for depression or anxiety at the start were excluded. That matters, because it lets the analysis ask whether diet came before symptoms, not after. The models adjusted for physical activity, age, sex and socioeconomic status, and diet was self-reported.
How much did fruit matter?
Each additional daily serving of any fruit was associated with a 13 percent lower risk of depression symptoms and a 7 percent lower risk of anxiety symptoms. Average intake ranged from two to two and a half servings a day, Medical Xpress reported.
Higher consumption of sugar-sweetened drinks, meaning soft drinks, cordials and sports drinks, was linked with greater risk of both conditions. The link appeared in boys and girls, and it was stronger in boys, particularly for anxiety.
Does this prove fruit protects mental health?
No. This is an observational study, so it cannot show that fruit prevents symptoms or that sugary drinks cause them. Teenagers who eat well may differ in ways the models did not capture, and self-reported diets can be inaccurate. Lead author Dr Lily Davidson said the team is not saying an apple will prevent depression or a soft drink will cause anxiety.
Senior author Associate Professor Katrina Champion pointed instead at the surroundings: making nutritious food affordable and reducing teenagers' exposure to sugary drinks, with schools, families and governments all playing a part.
What should families take from it?
This article is reporting, not medical or dietetic advice. Mental health problems have many causes, and a change in food is not a treatment. A teenager showing persistent low mood, worry or changes in eating should be seen by a doctor or another clinician who knows their history, and nobody should make restrictive diet changes for a young person without that guidance.
The authors' next job is to find out whether changing what teenagers eat changes how they feel, which needs trials and not surveys. Until then, the finding is a reason to make fruit easy to reach, not a promise.
Published in The Outspoken Digest
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Outspoken Digest Nutrition DeskDiet, food science and the evidence behind claims about what we eat.
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