SunGold Kiwifruit and Psychological Health (GoKiPH): A Randomised Controlled Crossover Trial

Background/Objectives: The consumption of SunGold kiwifruit, a fruit rich in vitamin C, has been associated with improved mood in healthy individuals with low vitamin C levels. However, no studies have examined this relationship in individuals with elevated mood disturbance. This study examined the potential for SunGold kiwifruit to improve psychological wellbeing in mood-disturbed adults. Methods: This study was a two-period, non-blinded crossover trial. Adults (n = 26) aged 18-60 years with mild to moderate mood disturbance were randomised with a two-week washout between periods. During each 4-week period, participants consumed either two SunGold kiwifruit daily or their usual diet. The primary outcome was mean change in total mood disturbance scores from the kiwifruit period compared to the diet-as-usual period. Secondary outcomes were blood plasma vitamin C concentration, wellbeing, vitality and gastrointestinal symptoms. Participants and researchers were unblinded to condition and intervention. Results: Scores for total mood disturbance (65.2%, p < 0.001), wellbeing (10.5%, p < 0.01) and vitality (17.3%, p = 0.001) significantly improved in the kiwifruit condition compared to the usual diet. Vitamin C (27.5%, p = 0.002) concentrations also improved and gastrointestinal symptom reduction was evident during kiwifruit consumption (16.2%, p = 0.003). There were no serious adverse events. SunGold kiwifruit consumption resulted in significant reductions in total mood disturbance scores and improvements in wellbeing, vitality and vitamin C concentrations. Gastrointestinal symptom severity also significantly reduced. Conclusions: Results provide preliminary evidence of the potential benefits of kiwifruit for reducing mood disturbance in adult populations. Further studies in diverse groups, including clinical populations, are warranted.