Eating more fruits and vegetables can lead to optimal sleep duration

Good health depends on healthy nutrition and sufficient exercise and sleep. There are clear associations between these components; For example, good nutrition provides energy for exercise, and many people report that getting enough exercise is important for their ability to get enough sleep. How can diet affect sleep?

A new study examines the link between fruit and vegetable intake and sleep duration. The research, conducted by a team from Finland’s University of Helsinki, the National Institute for Health and Welfare and Turku University of Applied Sciences, is published in Limits in nutrition.

Why sleep is important and how it works

Sleep gives our bodies a chance to rest and recover from waking activities. Our hearts, blood vessels, muscles, cells, immune systems, cognitive skills and memory abilities depend on regular, healthy sleep for optimal functioning, and a 2019 study suggests that sleep is important for repairing DNA damage that occurs while awake.

A good night’s sleep occurs in 3 to 5 night cycles, each lasting an average of 90 to 120 minutes. During each cycle, we start with a phase of non-rapid eye movement (REM) sleep, then move through two progressively deeper periods of non-REM sleep before emerging. Our non-REM sleep becomes lighter and lighter until we reach a REM phase, at which point a new cycle begins, or we wake up. Adults should aim to sleep 7 to 9 hours per night.

However, recent studies show that insomnia and shorter sleep duration are becoming increasingly common in adults. Due to factors such as stress, fast food consumption, and sedentary lifestyles, sleep deprivation has become a public health problem, linked to cardiovascular disease, decreased cognitive skills, and an increase in all-cause mortality.

In this new study, the researchers wanted to investigate how sleep duration could influence fruit and vegetable consumption, and vice versa. They also examined the role that individual chronotypes (preferences for the timing of activities, such as morning or evening) might play in food choices and sleep duration.

Recommended intake of fruit and vegetables for adults

The World Health Organization recommends that people consume at least 400 grams of fruits and vegetables daily most recent advice of the Nordic Council of Ministers recommends a higher intake, with between 500 g and 800 g of “vegetables, fruits and berries encouraged, with half of consumption coming from vegetables.”

However, research shows that adults in many countries do not meet the minimum intake. According to the new research, only 14% of Finnish men and 22% of Finnish women consume the recommended daily minimum of 500g of berries, fruits and vegetables.

The research team examined details from the National FinHealth 2017 Study. A total of 5,043 adults aged 18 years and older (55.9% female; mean age = 55 years) [SD 16.0]), submitted detailed responses to a 134-item questionnaire about the composition and frequency of their usual daily food intake in the most recent twelve months, and reported their chronotypes (tendency to sleep at a certain time of day) and typical sleep duration within a certain time. Period of 24 hours.

Three sleep duration categories emerged from these responses: short (less than 7 hours/day; 21%), normal (7–9 hours/day; 76.1%), and long (9+ hours/day; 2.9%). . Short sleepers had an average sleep duration of 6 hours; for normal sleepers the average duration was 7.7 hours, and for long sleepers the average duration was 10.1 hours. A majority of participants (61.7%) categorized themselves as intermediate chronotypes, while 22.4% identified themselves as morning types and 15.9% identified as evening types.

The researchers included chronotypes as a study covariate, noting that many studies have not included these as potential confounders. However, some research shows that they can influence dietary behavior. The researchers state: “Studies have shown that evening chronotypes are often associated with unhealthy dietary behaviors, including a tendency toward obesity-related eating habits.”

Findings: Both the quantity and the specific choice of fruit and vegetables are important

One of the notable results was that normal sleepers showed higher fruit and vegetable intake than both short and long sleepers across all fruit and vegetable subgroups. However, intake of different fruits and vegetables produced varying results.

The study explains: “In the vegetable subgroup, significant differences were observed in the consumption of green leafy vegetables, root vegetables and fruit vegetables (e.g. tomatoes, cucumbers) between normal and short sleepers.

“Significant differences were again noted for green leafy vegetables and fruit vegetables for normal versus long sleepers. However, other fresh and canned vegetables such as cabbage, mushrooms, onions, peas and beans showed no significant differences.

“In the fruit subgroups, a significant mean difference was observed in the consumption of berries and other fresh and canned fruits between normal and short sleepers. Conversely, for normal versus long sleepers, the only significant difference was observed in apple consumption.”

A relationship between fruit/vegetable intake and sleep duration categories, but not chronotypes

The researchers also noted that sleep duration categories could indicate expected levels of fruit and vegetable intake to a lesser extent. This is consistent with the results of a 2023 study in the International Journal of Behavioral Nutrition and Physical Activity which showed that adolescents had reduced fruit and vegetable intake the day after a night of short sleep duration.

This new study also found that chronotypes play a minimal role in the link between fruit and vegetable intake and sleep duration. The 2023 study found no association between fruit and vegetable intake and chronotypes.

The researchers note that overall reduced intake of certain fruits and vegetables is associated with long and short sleep duration. They recommend more specific work in this area for better understanding.

‘Targeted interventions aimed at [fruit and vegetable] subgroups with distinct associations, such as green leafy vegetables and fruit vegetables, can lead to impactful behavioral changes. Additional research, especially longitudinal studies, is needed to better understand these links and their implications for public health, especially in regions with similar population structures and dietary patterns as Finland,” they conclude.

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