In a small randomized trial in the United Kingdom, adults who incorporated one serving of 100% fruit juice or a smoothie into their healthier diet experienced notable reductions in depression scores after just four weeks.

Daily consumption of 100% fruit juice or a smoothie can enhance mental health, supporting the UK’s Five Healthy Eating Five Days guidelines. Image credit: Joseph Musila.

“While many recognize the benefits of consuming five servings of fruits and vegetables daily, implementing this can be challenging,” stated lead author Dr. Courtney Neale, who conducted the study at Newcastle University and is currently at the University of Liverpool.

“Our trial demonstrated that targeted financial and educational support to overcome common obstacles in achieving five servings can lead to significant dietary improvements for individuals with low fruit and vegetable consumption.”

“We discovered that straightforward, cost-effective strategies, like drinking a modest glass of 100% fruit juice or a smoothie each day, can assist individuals in meeting their five-a-day target while also offering potential mental health benefits.”

In this study, Dr. Neale and colleagues focused on participants who consumed one glass of 100% fruit juice or a smoothie daily as part of a five-a-day healthy eating strategy.

Adults with insufficient fruit and vegetable intake received support to enhance their daily consumption, either with or without a glass of juice or a smoothie to comply with the five-a-day guideline.

The 42 participants were divided into three groups: a control group that maintained their usual diet, a group that increased their intake of whole fruits and vegetables, and a group that did the same while also consuming a daily glass of juice or a smoothie.

After four weeks, both groups showed a rise in fruit and vegetable consumption, but the group that added fruit juice reported lower depression scores.

Specifically, depression questionnaire scores were 2.52 points lower (out of 27) compared to the control group, indicating a modest yet statistically significant difference, with no adverse effects on metabolic health indicators observed.

Lead author Dr. Oliver Shannon, a Lecturer in Nutrition and Aging at Newcastle University, noted: “With the UK facing rising living costs, the price of fresh produce can be a significant barrier for individuals aiming to increase their fruit and vegetable intake.”

“This research indicates that incorporating a glass of fruit juice or a smoothie daily could be part of the solution to achieving the five-a-day goal.”

“The finding that juice consumers had lower depression scores is promising and warrants further investigation, particularly among those experiencing mental health issues.”

“This aligns with existing research suggesting improved blood flow to the brain and enhanced cognitive function following the consumption of citrus juices.”

“Simple dietary modifications, including increasing fruit intake and adding a daily glass of juice, may be pivotal in supporting mental well-being.”

For more information, refer to the study published in the May 22 issue of the British Journal of Nutrition.

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Courtney Neale et al. Including fruit juices and smoothies in the recommended five-daily intake of fruits and vegetables: a randomized controlled trial investigating effects on intake, mood, and health markers. British Journal of Nutrition published online on May 22, 2026. doi: 10.1017/S0007114526107569