Kiwifruit has proven itself as a powerful mood booster – and new research from the University of Otago has shown just how fast its effects can be.
In a study published in the British Journal of Nutrition, researchers found the furry fruit improved vitality and mood in as little as four days.
Co-author Professor Tamlin Conner of the Department of Psychology said the findings point to a tangible and accessible way for people to support their mental wellbeing.
“It’s great for people to know that small changes in their diet, like adding kiwifruit, could make a difference in how they feel every day.”
Vitamin C intake has been associated with improved mood, vitality and wellbeing, and lower depression. Vitamin C deficiency is associated with higher depression and cognitive impairment.
However, Conner said limited research has assessed how quickly mood improvements occur after introducing vitamin C supplements or whole food sources.
The researchers aimed to fill that gap with an eight-week dietary intervention of 155 adults with low vitamin C.
Participants took either a vitamin C supplement, placebo, or two kiwifruit daily.
They reported their vitality, mood, flourishing, sleep quality, sleep quantity and physical activity, using smartphone surveys.
The researchers found kiwifruit supplementation improved vitality and mood within four days, peaking at around 14–16 days, and improved flourishing from Day 14. Vitamin C, on the other hand, marginally improved mood until Day 12.
Lead author Dr Ben Fletcher, who conducted the research as part of his PhD at Otago, said understanding the nuances of when and how these effects occur day-to-day contributes to our knowledge of the potential benefits of vitamin C-rich foods and supplements on mental health.
“This helps us see that what we eat can have a relatively fast impact on how we feel.
“Our participants had relatively good mental health to begin with so had little room for improvement, but still reported the benefits of kiwifruit or vitamin C interventions,” he said.
While vitamin C tablets showed some improvements, Fletcher said the study underscores the potential synergistic effects of consuming whole foods like kiwifruit.
“We encourage a holistic approach to nutrition and wellbeing, incorporating various nutrient-rich foods into your diet.”
