Daily Fruit Juice or Smoothie May Enhance Mental Well-Being, Study Finds

Consuming a daily glass of 100% fruit juice or a smoothie while adhering to the UK’s 5-a-day fruit and vegetable guideline could positively impact mental health, according to research from Newcastle University. The study revealed that adults typically ingesting lower amounts of fruits and vegetables showed improved mental well-being after increasing their dietary intake.

The randomized controlled trial, which involved 42 adults consuming two or fewer portions of fruits and vegetables per day, provided participants with financial and educational support to boost their intake towards the 5-a-day target. Over four weeks, participants were divided into three groups: one acting as a control group, the second group instructed to increase whole fruits and vegetables only, and the third group encouraged to include one glass of fruit juice or a smoothie daily along with whole fruits and vegetables.

Results indicated that both intervention groups increased their overall fruit and vegetable consumption. However, those who included juice or smoothies reported lower depression scores, with a statistically significant reduction of 2.52 points on a 27-point scale compared to the control group.

Positive Dietary Changes

Dr. Courtney Neal, who conducted the study while at Newcastle University and is currently at the University of Liverpool, emphasized the challenge many face in achieving the 5-a-day goal. She stated, “Our trial showed that when people with low fruit and vegetable intake were provided with targeted financial and educational support… they were able to make meaningful changes to their diet.”

Both intervention groups experienced an estimated increase of 8-10 grams in daily fiber intake, demonstrating that adding juice did not hinder the consumption of fiber-rich foods. Moreover, concerns regarding the sugar content of fruit juice did not translate to adverse effects on metabolic health markers among participants consuming fruit juice or smoothies.

Dr. Oliver Shannon, a senior author of the study, remarked that amid rising living costs in the UK, the price of fresh produce serves as a hurdle for many attempting to incorporate more fruits and vegetables into their diets. He noted, “Drinking a daily glass of fruit juice or a smoothie could be part of the solution and help people reach 5-a-day fruit and vegetable targets.” He added that the reduced depression scores among juice consumers merit further investigation, particularly among individuals struggling with mental health issues.

The peer-reviewed study was published in the British Journal of Nutrition, supported by the Fruit Juice Science Centre, and underscores the potential mental health benefits of relatively simple dietary modifications.