- Diet contributes to overall well-being by influencing various aspects of physical and mental health.
- Researchers are still trying to understand which components of the diet may have the greatest impact on mental health.
- A recent study found that eating kiwi helped improve mood within a few days in people with low vitamin C levels.
Following a healthy diet helps support quality of life, but researchers and nutritionists are still trying to understand the mechanisms that drive the link between food and mood.
A recently published study British Journal of Nutrition examined how kiwi and vitamin C affected mood and how quickly participants experienced mood improvements.
The results show that eating kiwi improved mood after 4 days, and the effect on vitality and mood was slightly stronger than in study participants taking vitamin C supplements.
The findings point to the effects of vitamin C on mental health and that whole food sources may be the best way to get this nutrient.
Fruits are part of a healthy diet, and kiwi is one option that offers many benefits.
For example, kiwi may aid gastrointestinal function and improve blood sugar and lipid levels. It contains fibre, potassium, vitamin E and very high levels of vitamin C.
Previous studies suggest that vitamin C supplements and vitamin C-rich fruits may help improve mood.
For the current study, researchers hypothesized that vitamin C may play a role in mood and healthy brain function. They were wondering how fruit intake could potentially affect mental health over a period of time.
This particular study analyzed data from a three-arm placebo-controlled trial. Participants were adults aged 18 to 35 with low plasma vitamin C levels.
The researchers divided the participants into three groups: One group was given a daily vitamin C supplement, the second group was given two kiwis a day, and the third group was given a daily placebo tablet.
Researchers used smartphone surveys to collect data from participants, and they had blood tests taken every 2 weeks.
They were unable to blind participants or researchers to the kiwi intervention. But researchers and participants did not know who received the vitamin C tablet versus the placebo until the study was completed.
Participants received their assigned intervention or placebo for four weeks and answered surveys every other day. The surveys collected data on several components, including:
- energy and fatigue
- mode
- developing
- sleep quality and quantity
- physical activity levels
Based on their analysis, the researchers found that participants who consumed kiwi saw improvements in mood and vitality in approximately 4 days, and improvement in growth by day 14.
For these participants, mood improvements peaked between day 14 and day 16. Participants in the vitamin C supplement group saw improvements in mood by day 12.
Study author Tamlin Conner, PhD, a psychological scientist and professor in the Department of Psychology at the University of Otago in New Zealand, said: Today’s Medical News:
“As part of this placebo-controlled nutritional study, we used smartphone technology to investigate mood over an 8-week period and found improvements in mood following the introduction of a whole food vitamin C product (Sungold kiwi) in as little as four days and two days later.” It reaches its peak around the week.
Our research program suggests that it is valuable to frequently measure real-time mood changes in daily life within intervention trials to understand patterns and time frames of change. “We were surprised that participants randomly assigned to the whole food condition (2 Sungold kiwis per day) showed improvements in mood even four days after the intervention.”
The study points out the importance of including vitamin C in the diet and how this nutrient can benefit mental health. It also suggests that the benefit may be most pronounced when obtained from whole food sources.
“This trial highlights an important difference between food-based vitamins and those that come from synthetic sources,” said study author Rick Miller, registered dietitian and nutritionist.
“These are not equivalent and a ‘whole food first’ approach should always be the first port of call to meet nutritional needs and symptoms that may be associated, such as mood.”
Despite the promising findings supporting the benefits of kiwi consumption, the study has some limitations.
First, it was observational, so it cannot prove that kiwi fruit causes mood improvement or other results. Second, it relied on participants’ self-reporting, which does not always guarantee accuracy.
The study was also conducted over 8 weeks and only included a relatively small number of adult participants within a certain age range.
The setup of the surveys may also have limited the findings. For example, researchers included only limited data from the mood states rating scale profile in participant surveys, and researchers only sent surveys to participants every other day.
Participants were also relatively healthy psychologically, so it is unclear how beneficial the intervention would be for those who are more emotionally distressed.
The researchers also did not specify how long participants needed to consume the supplements or kiwi, and future research could examine the impact of this timing on the results.
Ethnic differences between groups may also have affected the results. The researchers also acknowledge that other components of kiwifruit other than vitamin C likely contributed to the participants’ observed mental health benefits. Finally, the researchers acknowledge that there is a risk of positive response bias in the assignment of some clinics to the kiwi or tablet intervention and that some clinics have an element of non-randomization.
Dr. Conner highlighted the following areas for continued research:
“We want other scientists to test time-course patterns in mood following nutritional interventions. Replication is important in science. For whom are dietary interventions most beneficial? Do some people benefit more or less from vitamin C? What demographic, psychological, or behavioral factors predict variability in the mood benefits of vitamin C?” Are there environmental differences?
Overall, the results still point to the benefits of kiwi and vitamin C for mental health.
Double board of directors Dr. “The strength of the findings for people with low vitamin C levels is impressive and it was impressive to see that kiwifruit stood out from vitamin C tablets, suggesting a lack of response to placebo vitamin C tablets,” said Alex Dimitriu. Certified psychiatrist and sleep medicine specialist and founder of Menlo Park Psychiatry and Sleep Medicine in California, told MNT. Dr. Dimitriu was not involved in the research.
“A good guidance would be to add a fruit control that is not high in vitamin C, as well as kiwi fruit. “For people who do not eat enough citrus fruits or possibly have low vitamin C levels, studies such as these support that getting more vitamin C in their diet would provide a significant benefit from a relatively risk-free and cost-free intervention,” he added.
“Given the obvious benefits of normal vitamin C levels, this study underscores the importance of consuming healthy amounts of citrus fruits.”[or] vitamin C in one’s diet. “The speed of these developments in our impatient world is remarkable.”