A Daily Glass Of Fruit Juice Was Linked To Lower Depression Scores In A New Clinical Trial

A randomized controlled trial from Newcastle University has found that adults who added one daily glass of 100 percent fruit juice or a smoothie to a diet already being improved toward the recommended five-a-day fruit and vegetable target showed significantly lower depression scores than those who increased their fruit and vegetable intake through whole produce alone. The study, published in the British Journal of Nutrition, recruited 42 adults who were eating two or fewer portions of fruit and vegetables per day and split them into three groups: one group continued their usual diet as a control, a second received support and educational resources to reach five-a-day using whole fruits and vegetables only, and a third received the same support but also drank one glass of fruit juice or a smoothie daily. All participants received a small weekly budget to support the dietary changes. After four weeks, both intervention groups had increased their fruit and vegetable intake meaningfully. But only the group that included juice showed a statistically significant improvement in depression scores, scoring 2.52 points lower on the 27-point PHQ-9 depression scale compared to the control group, with an average score of 2.93 in the juice group versus 5.45 in the control, a difference the researchers described as modest but real.

The finding is preliminary: the study included only 42 participants and lasted four weeks, and the researchers are careful to describe the results as promising rather than conclusive, calling for further research particularly among people already experiencing poor mental well-being. Importantly, both intervention groups also increased their daily fiber intake by an estimated 8 to 10 grams, and no adverse effects on metabolic health markers were observed in the juice group despite ongoing public conversation about the sugar content of fruit juice, suggesting that one glass per day within a balanced diet did not cause the metabolic concerns sometimes associated with liquid fruit consumption. Dr. Oliver Shannon, a lecturer in nutrition and ageing at Newcastle and one of the study's senior authors, said the finding backs up existing research reporting improved brain blood flow and cognitive function after citrus juice consumption, and that simple dietary changes including a daily glass of juice could play a role in supporting mental well-being. Only about 17 percent of UK adults currently meet the five-a-day recommendation, and fewer than 10 percent of teenagers do, making the identification of practical, low-cost approaches to increasing fruit intake alongside potential mental health benefits a meaningful public health finding regardless of the trial's small size.

Source:https://www.sciencedaily.com/releases/2026/08/260808235003.htm