Food behaviors, movement behaviors and sleep: what links?
Increasing fruit and vegetable consumption improves sleep characteristics in women
Sufficient and high-quality sleep is highly important for physical and mental health (Freeman, 2017; Milojevich, 2016). Yet, in the US, young adults have a high prevalence to suffer from poor sleep quality and short sleep duration (Gradisar, 2013). Indeed, about half of US young adults aged between 19-32 years self-reported problems with sleep, falling asleep, non-refreshing sleep or poor perceived sleep quality according to a nationally representative survey (Levenson, 2016). Many socioeconomic and lifestyle factors, including dietary intake, may influence sleep characteristics (Jansen, 2020a; Jansen, 2020b).
Therefore, the present study aimed to evaluate whether increases in fruit and vegetable consumption were associated with concomitant changes in insomnia symptoms, sleep duration and sleep quality. A secondary longitudinal analysis of data was performed using the baseline and 3-month follow-up data from the randomized trial “MENU Gen-Y”.
Participants increased fruit and vegetables intake by 1.2 servings on average at 3-month follow-up
The sample included 1,165 young adults who were low consumers of fruit and vegetables at baseline (<3 serving/day). The mean age was 26 years, with 71% women. Average sleep duration was 7h24 during weekdays and 8h16 on weekends.
Over a period of 3 months, participants increased their fruit and vegetables intake by 1.2 servings on average, although 23% did not change their intake and 8% consumed less fruit and vegetables.
As regards to sleep characteristics, sleep duration, sleep quality, and time to fall asleep remained, across all participants, constant over the 3-months period. Yet, young adults with the highest physical activity at baseline reported a reduction in time to fall asleep.
An increase in fruit and vegetables intake improved insomnia symptoms, sleep quality and time to fall asleep mainly in women
Overall, the presence of insomnia symptoms remained the same for approximately 76.29% of the participants; 9.97% worsened insomnia symptoms whereas 13.75% reported an improvement.
Over the 3-months period, participants who increased their fruit and vegetables consumption by 3 or more servings reported modest improvements in sleep latency and insomnia compared to those with no change or smaller increases in their intake. However, no differences in sleep duration were observed. Moreover, gender-stratified analyses revealed that associations between increasing fruit and vegetable intake and sleep quality were primarily found among women.
In particular, women who increased their intake by 3 servings/ day at 3 months were 2 times more likely to report improved insomnia symptoms. They have also reported a 4-minute reduction in time to fall asleep, a 0.2-point higher sleep quality score and were 80% more likely to change from having poor to good/excellent sleep quality compared to those who did not change or reduced their fruit and vegetable intake.
A link that could be explained by the quality of diets that include fruit and vegetables
The link between fruit and vegetables consumption and improvements in sleep could be explained by a few mechanisms. The first explanation could be the fact that fruit and vegetables are key components of anti-inflammatory diets known for their potential benefits to improve sleep by promoting production of melatonin and other neurotransmitters involved in onset and maintenance of sleep (Godos, 2019).
Increasing fruit and vegetables consumption is also related to improvement in other aspects of the diet such as a reduced intake of processed foods, meat, and/or snacking which have been associated with lower sleep quality (Crispim, 2011; Lana, 2019).
Gender differences found in the study may be due to notably higher prevalence of insomnia in women than men. Therefore, there may be more fluctuations in insomnia-related symptoms that are in turn sensitive to changes in lifestyle among women.
Based on: Jansen EC, et al. Changes in fruit and vegetable consumption in relation to changes in sleep characteristics over a 3-month period among young adults. Sleep Health. 2021;7:345-352.
- Design and intervention: A secondary longitudinal analysis of data was conducted utilizing the baseline and 3-month follow-up data collection from MENU GenY, a randomized trial that sought to improve fruit and vegetables intake using a tailored online intervention.
- Setting: Integrated health care systems in Detroit, Michigan and Danville, Pennsylvania.
- Participants: About 1165 young adults who were low consumers of fruit and vegetables (<3 servings/day) at baseline.
– Fruit and vegetables changes were categorized into 4 categories: no changes or decrease, 1 serving increase, 2 serving increase, and 3 or more serving increase.
– Changes in sleep characteristics were self-reported across the fruit and vegetables change categories: chronic insomnia classification (yes or non), sleep duration, quality, and time to fall asleep.
– Analyses were both overall and stratified by gender, adjusting for potential confounders (depression, physical activity, education, children, and study site).
- At 3-month follow-up, participants on average increased their fruit and vegetables intake by 1.2 servings.
- Women who increased fruit and vegetables intake by 3 or more servings showed improvements in insomnia symptoms, sleep quality, and time to fall asleep compared to women who did not change or decreased their fruit and vegetables intake. Associations were not as apparent among men.
- These findings highlight that increasing fruit and vegetables intakes among young women with low fruit and vegetables intake could be an additional therapeutic recommendation for those experiencing insomnia.