Eating More Fruits and Vegetables May Lead to Optimal Sleep Duration

Good health depends on a healthy diet, sufficient physical activity and sleep. There are clear associations between these components; for example, a good diet provides energy for exercise, and many people report that it is important to get enough exercise to be able to get enough sleep. So how can nutrition affect sleep?

A new study examines the link between fruit and vegetable consumption and sleep duration. The research, carried out by a team from Finland’s University of Helsinki, the National Institute of Health and Social Welfare and the Turku University of Applied Sciences, is published in Nutrition Frontiers.

Why sleep is important and how it works

Sleep gives our body the opportunity to rest and recover from waking activity. Our heart, blood vessels, muscles, cells, immune system, cognitive abilities, and memory skills depend on regular, healthy sleep for optimal functioning, and a 2019 study suggests that sleep is important for repair DNA damage that occurs during wakefulness.

Restorative sleep occurs in 3 to 5 nightly cycles, each lasting on average 90 to 120 minutes. During each cycle, we begin with a stage of rapid eye movement (REM) sleep, then move through two progressively deeper periods of non-REM sleep before exiting. Our non-REM sleep becomes lighter and lighter until we reach a REM stage, after which a new cycle begins, or we wake up. Adults should aim to get 7 to 9 hours of sleep per night.

However, recent studies show that insomnia and reduced sleep duration are increasingly common among adults. Due to factors such as stress, fast food consumption and sedentary lifestyles, lack of sleep is emerging as a public health problem, linked to cardiovascular disease, decreased cognitive abilities and increased all-cause mortality.

In this new study, researchers wanted to explore how sleep duration might affect fruit and vegetable consumption, and vice versa. They also studied the role that individual chronotypes (activity preferences, such as morning or evening) might play in food choices and sleep duration.

Recommended intake of fruits and vegetables for adults

The World Health Organization recommends that people consume at least 400g of fruit and vegetables per day, while the most recent advice from the Nordic Council of Ministers recommends higher consumption, encouraging between 500g and 800g of ” vegetables, fruits and berries”, with half of consumption coming from vegetables.”

However, studies show that in many countries adults do not meet the minimum intake. According to the new study, 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 reviewed details from the 2017 National FinHealth Study. A total of 5,043 adults, ages 18 and older (55.9% female; mean age = 55 years (SD 16.0 )), submitted detailed responses to a 134-item questionnaire on the composition and frequency of their usual daily food intake over the past 12 years. months, and reported their chronotypes (tendency to sleep at a certain time of day) and typical sleep duration over a 24-hour period.

From these responses, three categories of sleep duration emerged: short (less than 7 hours/day; 21%), normal (7 to 9 hours/day; 76.1%) and long (9 hours or more/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%) classified themselves as intermediate chronotypes, while 22.4% specified that they were a morning type and 15.9% identified themselves as an evening type.

The researchers included chronotypes as study covariates, noting that many studies did not include them as potential confounders. However, some research shows that they can affect eating behaviors. The researchers say: “Studies have shown that evening chronotypes are often associated with unhealthy eating behaviors, including a propensity for obesity-related eating habits. »

Results: Quantity and specific choices of fruits and vegetables are important

Among the notable findings, normal sleepers showed higher fruit and vegetable intake than short and long sleepers, across all fruit and vegetable subgroups. However, eating different types of fruits and vegetables has shown varying results.

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

“Similarly, for normal sleepers and long sleepers, significant differences were again noted for green leafy vegetables and fruiting vegetables. However, other fresh and canned vegetables such as cabbage, mushrooms, onion, peas and beans did not show significant differences.

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

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

The researchers also observed that sleep duration categories might indicate, to a lesser extent, expected levels of fruit and vegetable consumption. This is consistent with the results of a study carried out in 2023 in the International Journal of Behavioral Nutrition and Physical Activity which revealed a decrease in fruit and vegetable consumption among adolescents the day following a night of short sleep.

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

Researchers observe that overall, reduced consumption of certain fruits and vegetables is linked to long and short sleep duration. They recommend more specific work in this area for better understanding.

“Targeted interventions focused on subgroups (of fruits and vegetables) with pronounced associations, such as green leafy vegetables and fruiting vegetables, can lead to impactful behavior change. Additional research, particularly longitudinal studies, is needed to better understand these associations and their public health. implications, especially in regions with similar population structures and dietary patterns to Finland,” they conclude.