SunGold Kiwifruit and Psychological Health (GoKiPH): a randomised, crossover trial

Abstract

Gold kiwifruit consumption and increased vitamin C intake have been associated with improved mood, vitality, and wellbeing in healthy individuals^(1,2). However, to date, no studies have focussed exclusively on the efficacy of gold kiwifruit for improving such outcomes in participants with disturbed mood. A randomised crossover trial was undertaken to examine the efficacy of Zespri^TM SunGold^TM kiwifruit for improving psychological wellbeing and vitamin C concentrations in adults with sub-clinical levels of mood disturbance. In a two-period, non-blinded crossover trial, N = 26 adults aged 21 to 60 years (M = 36.1, SD = 11.0) with mild to moderate mood disturbance were randomised to a counter-balanced sequence. Participants consumed 2x SunGold kiwifruit daily or their typical diet for four weeks, with a two-week washout between periods. The primary outcome was change in mood disturbance, with secondary outcomes including plasma vitamin C, wellbeing, vitality and gut health. Results indicated a significant time x treatment interaction effect for mood disturbance (F(2,107.3) = 6.19, p = ,003) with significant improvements in mood disturbance scores between baseline and post-intervention during the SunGold kiwifruit period. A significant time x treatment interaction effect for blood plasma vitamin C (F(2,98.5) = 3.65, p = ,029) also demonstrated increased vitamin C concentrations during the SunGold kiwifruit period. A significant time x treatment interaction effect for wellbeing (F(2,104.7) = 4.5, p = ,013) was evident with wellbeing significantly improved between baseline and post-intervention during the SunGold kiwifruit period. The time x treatment interaction for vitality approached significance (F(2,104.7) = 2.89, p = ,06) with increases in vitality following SunGold kiwifruit consumption. These results provide preliminary evidence that SunGold kiwifruit consumption improves psychological wellbeing in mood-disturbed adults, which corresponds to increased plasma vitamin C concentrations. Future research is required to replicate this effect and to further demonstrate the potential benefit of whole-food interventions for treating mood-disturbance.