Summary: Researchers found that kiwifruit rapidly improves mood and vitality, with effects noticeable in just four days. The study involved an 8-week intervention with 155 adults with low vitamin C levels, comparing the effects of vitamin C supplements, placebo, and kiwifruit.
While vitamin C showed marginal mood improvements, kiwifruit supplementation led to a significant boost in vitality, mood, and overall flourishing. This research not only highlights the fast-acting benefits of kiwifruit on mental health but also emphasizes the advantages of whole foods over supplements.
Key Facts:
- Kiwifruit was found to improve mood and vitality within four days, peaking around 14-16 days.
- The study suggests whole foods like kiwifruit have synergistic effects on mental health, surpassing those of vitamin C supplements.
- This research introduces a novel method using intensive smartphone surveys for real-time tracking of mood changes.
Source: University of Otago
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, says the findings provide a tangible and accessible way for people to support their mental well-being.
“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, well-being, and lower depression, while vitamin C deficiency is associated with higher depression and cognitive impairment.
However, Professor Conner says 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 8-week dietary intervention of 155 adults with low vitamin C.
Participants took daily either a vitamin C supplement, placebo, or two kiwifruit. They then 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 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, says 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 says.
He adds that, while vitamin C tablets showed some improvements, the study underscores the potential synergistic effects of consuming whole foods like kiwifruit.
“We encourage a holistic approach to nutrition and well-being, incorporating various nutrient-rich foods into your diet.”
In addition to the direct implications for individuals seeking to improve their mental well-being, Professor Conner says the study introduces a novel methodology in nutritional research.
“The use of intensive smartphone surveys offers a real-time understanding of the day-to-day changes in mood-related outcomes.”
About this diet and mental health research news
Author: Ellie Rowley
Source: University of Otago
Contact: Ellie Rowley – University of Otago
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Smartphone survey data reveals the time course of changes in mood outcomes following vitamin C or kiwifruit intervention in adults with low vitamin C” by Tamlin Conner et al. British Journal of Nutrition
Abstract
Smartphone survey data reveals the timecourse of changes in mood outcomes following vitamin C or kiwifruit intervention in adults with low vitamin C
Vitamin C-rich foods can improve mood; however, the timecourse of these benefits is unknown. This study utilised intensive longitudinal smartphone surveys from a three-armed placebo-controlled trial to determine mood-related changes following supplementation with vitamin C (250 mg tablet/d), kiwifruit (2 SunGold™ kiwifruit/d) or a placebo (1 tablet/d). Secondary data were analysed from the KiwiC for Vitality trial (Trial ID: ACTRN12617001031358).
Adults (n 155, 63 % female, aged 18–35 years) with low plasma vitamin C (<40 μmol/l) completed a 14-d lead-in, 28-d intervention and 14-d washout. Participants self-reported vitality (SF-36), mood (POMS total mood disturbance), flourishing (flourishing scale), sleep quality, sleep quantity and physical activity every second day using smartphone surveys.
Plasma vitamin C, measured fortnightly, reached saturation after 2 weeks of vitamin C or kiwifruit supplementation. Kiwifruit supplementation improved vitality and mood within 4 days, peaking around 14–16 days, and improved flourishing from day 14. Vitamin C marginally improved mood until day 12.
Incremental AUC analyses revealed significant overall effects of kiwifruit consumption on vitality and mood compared with placebo, which were stronger than effects for vitamin C tablets, but attenuated when adjusting for covariates. Sensitivity analyses of participants with low baseline vitamin C status revealed improved mood (vitamin C and kiwifruit) and flourishing (kiwifruit only).
This is the first study to use intensive smartphone surveys to model the day-to-day timecourse of mood-related states following vitamin C intervention and highlights the value of using smartphone surveys to reveal the temporal changes in mood-related outcomes following nutrient supplementation.
