Kiwifruit has been proven to be a powerful mood booster, and new research from the University of Otago has shown just how rapid its effects can be. In a recently published study British Journal of NutritionResearchers found that the soft fruit improved vitality and mood in just four days.

Research results and implications

Co-author Professor Tamlin Conner, from the Department of Psychology, says the findings provide a concrete and accessible way for people to support their mental health.

“It’s great for people to know that small changes to their diet, like adding kiwi, can make a difference to how they feel every day.”

Vitamin C intake is associated with improved mood, vitality, well-being, and reduced depression; Vitamin C deficiency is associated with greater depression and cognitive impairment. But Professor Conner says limited research has assessed how quickly mood improves after administering vitamin C supplements or whole food sources.

Research methodology

Researchers aimed to fill this gap with an 8-week dietary intervention in 155 adults with low vitamin C levels. Participants took a vitamin C supplement, a placebo, or two kiwis per day. They then reported their vitality, mood, well-being, sleep quality, amount of sleep and physical activity via smartphone surveys.

Key results

Researchers found that eating kiwi increased vitality and mood for four days, days 14-16. He found that it reached its peak on days 14 and that well-being increased from day 14 onwards. Vitamin C, on the other hand, slightly improved mood by day 12.

Lead author Dr., who conducted the research as part of his doctoral study. I’m Fletcher. Understanding the nuances of when and how these effects occur on a daily basis adds to our knowledge of the potential benefits of vitamin C-rich foods and supplements for mental health, Otago says.

“It helps us see that what we eat can affect how we feel relatively quickly.

“Our participants’ mental health was relatively good to begin with, so there was little room for improvement, but they still reported benefits from the kiwi or vitamin C intervention,” he says.

Innovations

He adds that although vitamin C pills showed some improvement, the study highlights the potential synergistic effect of consuming whole foods like kiwis.

“We encourage a holistic approach to nutrition and wellness by incorporating a variety of nutrient-dense foods into your diet.”

Aside from its direct implications for people looking to improve their mental health, Professor Conner says the study represents a new methodology in nutrition research.

“Using intensive smartphone surveys provides real-time insight into daily changes in sentiment-related results.”