The Effects Of Kiwifruit Consumption On Sleep Quality, Fatigue And BMI Of Saudi Adults
Condition: Sleep Disturbance; Fatigue; Body Weight
MeSH terms: Dyssomnias; Parasomnias; Fatigue; Body Weight
Study type: Interventional

Summary: 
      Hypothesis: Kiwifruit contains antioxidants and serotonin which may be beneficial in the
      treatment of sleep disruption. Aim: to assess the effects of daily intake of kiwifruit on
      sleep quality, fatigue, and BMI among Saudi adults with poor sleep quality. Methods:
      Twenty-six female participants (14 cases, and 12 controls) were included. All participants
      were aged ≥18 years and were Saudi and had poor sleep quality. Pregnant, lactating and
      participants with any chronic diseases such as cardiovascular or neurological diseases, and
      history of using herbal or medications for inducing sleep for the last two months were
      excluded. Participants in the case group consumed 2 kiwifruits 1 hour before bedtime nightly
      for 6 weeks and the control group did not consume kiwifruit. The Pittsburgh Sleep Quality
      Index (PSQI) questionnaire was used to assess sleep quality before and after kiwi consumption
      (score ≥ 5 indicates poor sleep quality), Fatigue Severity Scale (FSS) was used to assess
      fatigue and anthropometrics were measured based on the WHO guidelines. After 6 weeks, sleep
      quality, fatigue and BMI were compared between cases and controls. Kiwifruit consumption may
      improve sleep quality in adults with self-reported poor sleep quality. Further investigation
      of the sleep promoting properties of kiwifruit is required.
    

Detailed description: 
      Introduction People spend almost one third of their lives in sleep and it is one of the main
      contributors to our life and wellbeing. Sleep quality has several components including sleep
      duration, timing, efficiency (time in bed spent asleep) and latency (the amount of time it
      takes to fall asleep). Sleep disruption may be defined as any change in the components of
      sleep quality. A cross-country comparative analysis reported the economic cost of
      insufficient sleep from 62,000 people in UK, US, Canada, Germany, and Japan. Insufficient
      sleep costs $411 billion annually for the US, $138 billion for Japan, £40 billion for UK, $60
      billion for Germany, and $21 billion for Canada. No study has measured the economic cost of
      sleep disruption in Saudi Arabia. This may be due to the fact that sleep medicine is
      relatively a new specialty in the medical community.

      The National Sleep Foundation recommends different sleep durations for individuals according
      to age. Adults aged between 18-64 years are recommended to sleep 7-9 h/day. In Saudi Arabia,
      33.8% of adults sleep less than 7 hours, and this was shown in women more than men. In
      meta-analyses, short sleep duration has been associated with an increased risk of obesity.
      Sleep disruption has been shown to increase the risk of cancer, type 2 diabetes mellitus,
      cardiovascular disease and coronary heart disease. Furthermore, sleep disruption has been
      associated with an increased risk of mortality. Collectively, sleep disruption has
      detrimental economic and health consequences and identifying the factors that may improve it
      is a public health priority. Thus, using interventions to improve sleep quality may help
      reduce disease risk and occurrence.

      Nutritional research studied the effects of micro and macronutrients and whole foods on sleep
      measures. Micronutrients studied in relation to sleep included tryptophan, zinc, B-vitamins
      and polyphenols. A recent systematic review explored the effects of macronutrient
      manipulation on sleep outcomes. Manipulating carbohydrate intake appeared to alter sleep
      outcomes in healthy individuals. Several food items were studied in relation to sleep
      outcomes including fish tart cherry juice and products and kiwi fruit. Despite these studies,
      nutritional advice that can be recommended for sleep hygiene is inconclusive due to limited
      interventional studies.

      Recently, kiwifruit has gained interest in regards to sleep outcomes. This may be due to the
      potential mechanisms of kiwifruit on sleep. Kiwifruit contain melatonin which is important
      for regulating the circadian rhythms and sleep cycles. Another potential mechanism is the
      high content of polyphenols, antioxidants, flavonoids, carotenoids, and anthocyanins that may
      decrease oxidative stress in people with sleep disorders or poor sleep quality. Furthermore,
      polyphenols may influence sleep through their effects on circadian rhythms, clock gene
      expression, and peripheral clocks. Kiwifruits contain a protein named actinidin which is
      involved in precursors of neurochemicals required for sleep-wake regulation. In addition,
      kiwifruit is rich in folate and vitamin c which are essential in the metabolism of amino
      acids into neurochemicals. Regardless of the potential mechanisms of kiwifruit on sleep, only
      two interventional studies were conducted to explore this relationship. However, one study
      did not include a control group and the intervention period in another study was only 4
      weeks.

      Therefore, investigators designed the study with the purpose of replicating the study with a
      control group and a longer intervention period to investigate whether kiwi has beneficial
      properties on sleep. Investigators conducted a randomized, controlled trial addressing
      whether intake of kiwifruit would improve sleep parameters in a Saudi student population with
      poor sleep quality.

      This study aims to 1) compare between sleep, fatigue and BMI in cases and controls at the
      start of the study and after 6 weeks in Saudi adults 2) Study the effects of kiwifruit
      consumption on sleep quality, fatigue, and BMI in Saudi adults.

      Study Hypothesis: Kiwifruit intake may improve sleep quality, fatigue and decrease BMI

      Materials and methods Study design: a pilot randomized controlled trial

      Participants: The study included university students aged ≥ 18 years with poor sleep quality
      from Umm Al-Qura University, Makkah, Saudi Arabia. Ethical approval was obtained from the
      Biomedical Research Ethics Committee at Umm Al-Qura University. No. HAPO-02-K-012. This study
      was carried out in accordance with the principles of the Helsinki Declaration. Participants
      were recruited through email and several social media platforms including WhatsApp™ and
      Twitter™ by a flyer between January-February 2022. Participants were invited to a screening
      visit (30-45 minutes) at Umm Al-Qura University Nutrition clinic to assess eligibility. In
      the screening visit, researchers explained the study aims and provided participants with a
      consent form and a kiwifruit consumption diary if eligible.

      Recruitment status: Completed

      Questionnaires:

      A questionnaire was created to be filled in by the participants in both visits. The
      questionnaire included a brief introduction and a consent statement "I agree to participate
      in this study. Before finishing the trial, I can freely and without consequences terminate my
      participation". In addition, it included demographic questions, sleep quality questionnaire
      (PSQI) and the Fatigue Severity Scale (FSS).

      Sleep quality Sleep quality was assessed using the validated Pittsburgh Sleep Quality Index
      (PSQI), which is an 18-item questionnaire. Two language versions of the PSQI were used;
      English, and the Arabic version that was translated by 10 Arabic bilingual translators was
      used. The PSQI is a subjective measure that assesses seven factors of sleep: sleep quality,
      sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep
      medication and daytime dysfunction. Each dimension scored between 0-3, with a total score
      ranging from 0-21. Higher scores indicate lower sleep quality. A global PSQI score higher
      than 5 points indicates poor sleep quality. Moreover, to analyze variables not considered by
      the PSQI, investigators included in the survey questions of stability of participants usual
      sleep/wake patterns and if they differ on weekends and how often they had naps.

      The Fatigue Severity Scale (FSS) Fatigue was assessed using the Fatigue Severity Scale (FSS)
      which is a self-administered questionnaire with 9 items (questions) investigating the
      severity of fatigue in different situations during the past week. Grading of each item ranges
      from 1 to 7, where 1 indicates strong disagreement and 7 strong agreements, and the final
      score represents the mean value of the 9 items. The researchers independently translated the
      original version of the questionnaire from English to Arabic. Prior to use in this study, the
      questionnaire was initially administered to 10 bilingual subjects, who completed both the
      Arabic version and the English version to determine the test-retest reliability. Fatigue was
      independent of the version.

      Study intervention Eligible participants were randomly assigned to either a non-kiwifruit
      feeding group (controls) or consumed two medium-size kiwifruit group [21] (cases) 1 hour
      before bedtime every night for 6 weeks (42 days in total). Randomization was performed by
      giving participants a note identifying the condition to which they were randomized; the note
      was placed in a sealed envelope. Blindness was not applicable since cases received kiwifruit
      and controls did not receive. Total number of kiwis consumed should be (14 kiwis (number of
      kiwis in one week) x 6 (number of weeks) = 84 kiwis in total. Participants consuming the
      kiwifruit were asked to keep a diary to record if they consumed them every day. During the
      6-week intervention period, participants received their kiwifruit every week on the first day
      of the week (Sunday) that is adequate for a week (14 kiwi fruits brand name: Sharbatly Co.
      Ltd, variety: Hayward, country of origin: Italy). The kiwifruits were supplied at optimum
      ripeness for consumption and were instructed to keep the kiwi in the fridge to prevent
      damage.

      Anthropometric measurements Participants' weight and height were measured via (GIMA Pegaso
      Digital Scale) on both visits to calculate their body mass index (BMI). WHO guidelines were
      used to take physical measurements of participants and BMI categorization was based on WHO.

      Statistical Analysis Data analysis was performed using Statistical Package for the Social
      Sciences, SPSS 23rd version. Frequency and percentages were used to display categorical
      variables. Mean and standard deviation were used to present numerical variables. The
      Shapiro-Wilk test was used to test normality. Independent t-test and paired t-test were used
      to test associations for normally distributed variables (age, duration of nap, BMI at both
      start and end of the study, fatigue score at both start and end of the study, PSQI at end of
      the study). While the Mann-Whitney U test and Wilcoxon Signed-Rank test were used for
      non-normally distributed variables (PSQI at start of the study). Pearson's correlation was
      also used to test for associations between numerical variables. The level of significance was
      set at 0.05.
    

Intervention name(s): Kiwifruit
Intervention type(s): Other
Intervention description(s): 2 kiwifruit for 6 weeks
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Eligible participants were randomly assigned to either a non-kiwifruit feeding group (controls) or consumed two medium-size kiwifruit group [21] (cases) 1 hour before bedtime every night for 6 weeks (42 days in total). Total number of kiwis consumed should be (14 kiwis (number of kiwis in one week) x 6 (number of weeks) = 84 kiwis in total. Participants consuming the kiwifruit were asked to keep a diary to record if they consumed them every day. During the 6-week intervention period, participants received their kiwifruit every week on the first day of the week (Sunday) that is adequate for a week (14 kiwi fruits brand name: Sharbatly Co. Ltd, variety: Hayward, country of origin: Italy). The kiwifruits were supplied at optimum ripeness for consumption and were instructed to keep the kiwi in the fridge to prevent damage.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Sleep; Fatigue; Body mass index; kiwifruit; Saudi Arabia; Randomized controlled trial