Study Links Daily Fruit Juice Intake to Lower Depression Symptoms

Could your morning smoothie do more than satisfy your sweet tooth? It might give your mood a little lift, too.

A new randomized trial, published in the British Journal of Nutrition, suggests that adding 100% fruit juice or a smoothie to a diet richer in fruits and vegetables may help support mental well-being, while also making it easier to reach recommended daily fruit and vegetable targets.

Researchers from Newcastle University studied 42 adults who typically consumed two or fewer portions of fruits and vegetables each day. Participants were randomly assigned to three groups for four weeks: a control group that maintained its usual diet, a group encouraged to reach five daily portions using whole fruits and vegetables, and a third group that followed the same advice while also drinking one glass of fruit juice or a smoothie each day.

Both dietary intervention groups successfully increased their fruit and vegetable intake. However, the juice and smoothie group showed an additional benefit: depression scores fell by 2.52 points on a 27-point scale compared with the control group.

Researchers also estimated that both intervention groups increased their daily fiber intake by around 8–10 grams, suggesting that participants continued adding whole, fiber-rich foods rather than simply replacing them with juice.

Importantly, no adverse changes in metabolic health markers were detected in the juice and smoothie group during the four-week study.

The findings add to growing research exploring links between diet and mental health. However, the study was small and short-term, hence, the results cannot prove that fruit juice directly reduces depression or establish long-term health effects.

The researchers suggest that practical, affordable options such as a small serving of 100% fruit juice or a smoothie, alongside whole fruits and vegetables, could help people increase overall fruit and vegetable consumption.

REFERENCE: Courtney Neal, et al.; Including fruit juice and smoothies within 5-a-day fruit and vegetable intake recommendations: a randomised controlled trial investigating impact on levels of intake, mood and markers of health. British Journal of Nutrition, 2026; 1 DOI: 10.1017/S0007114526107569