Drinking a glass of 100% fruit juice or a smoothie each day can lower depression scores and boost mental wellbeing, according to a new randomized controlled trial from Newcastle University. The study, published in the British Journal of Nutrition, shows that a simple, cost-effective dietary switch can meaningfully improve mood.
The Research
Dr. Courtney Neal and colleagues recruited 42 adults who ate two or fewer portions of fruits and vegetables daily. Participants were given financial and educational support to help them reach the UK's recommended “5-a-day” target. One group was instructed to meet this goal using only whole produce, while a second group added a small daily glass of 100% fruit juice or a smoothie. After four weeks, both groups increased their fruit and vegetable intake, but the juice-and-smoothie group saw a statistically significant drop in depression scores — a reduction of 2.52 points on a 27-point scale — compared to the whole-produce-only group. Researchers tracked metabolic health markers and found no adverse effects, and dietary recalls showed that juice did not displace fiber-rich whole foods; both groups increased fiber intake by 8–10 grams per day.
Why It Matters
Depression is one of the most common mental health conditions worldwide, and dietary interventions offer an accessible, low-cost complement to other treatments. This study suggests that even a small addition — one glass of 100% juice or a smoothie — can shift mood in a measurable way, likely by improving nutrient intake and brain blood flow. For people who struggle to eat enough fruits and vegetables, juice provides a practical bridge, without the metabolic downsides often feared. For cognitive health, better mood supports focus, motivation, and overall brain function.
What You Can Do
Consider adding one serving of 100% fruit juice or a smoothie to your daily routine. Combine it with whole fruits and vegetables to meet your 5-a-day target. Choose juices without added sugars, and pair them with fiber-rich foods to maintain digestive health. This simple, evidence-based swap could give your mental wellbeing a gentle boost.
Source: Neuroscience News
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