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 ZespriTM SunGoldTM 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.