Genetic inheritance is important to enjoy good health, but there are other factors that significantly influence and depend on us, such as eating a balanced diet that provides us with the necessary nutrients, practicing regular physical exercise and getting enough sleep. These factors are also related to each other and, for example, good nutrition provides energy for exercise and physical activity helps you sleep better. Therefore, the type of diet could affect sleep.
Now, a new study by a team from the Finnish University of Helsinki, the National Institute of Health and Welfare and the Turku University of Applied Sciences has analyzed the connection between fruit and vegetable intake and sleep duration. Their findings have been published in Frontiers in Nutrition.
Sleep provides the body with the opportunity to rest and recover from waking activity. Our hearts, blood vessels, muscles, cells, immune systems, cognitive abilities, and memory-building abilities depend on regular, healthy sleep for optimal functioning, and a 2019 study suggests sleep is important for repairing DNA damage. that occurs during wakefulness.
Restful sleep is divided into three to five nightly cycles, each lasting between 90 and 120 minutes, on average. During each cycle, we start with a stage of non-rapid eye movement (REM) sleep, then go through two increasingly deeper periods of non-REM sleep before emerging from them. 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 sleep between 7 and 9 hours per night.
However, recent studies show that insomnia and shorter sleep duration are increasingly common among adults. Factors such as stress, fast food consumption and a sedentary lifestyle mean that lack of sleep is becoming a public health problem linked to cardiovascular diseases, decreased cognitive ability and an increase in mortality from all causes.
Links between type of diet and sleep duration
The authors of the new study wanted to explore how sleep duration could influence fruit and vegetable consumption, and vice versa. They also investigated the role that individual chronotypes (activity time preferences, such as morning or evening) might play in dietary choices and sleep duration.
The World Health Organization recommends that people consume at least 400 g of fruits and vegetables a day, while the most recent advice from the Nordic Council of Ministers recommends a higher intake, specifically between 500 and 800 g of “vegetables, fruits and berries, and half of consumption will come from vegetables.
However, studies show that adults in many countries do not meet the minimum intake. According to 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 the details of the 2017 National FinHealth Study. A total of 5,043 adults, ages 18 and older (55.9% women, with a median age of 55 years) submitted detailed responses to a 134-item questionnaire about the composition and frequency of their usual daily food intake over the past 12 months and reported on their chronotypes (tendency to sleep at a certain time of day) and typical sleep duration within a 24-hour period.
People who slept what is considered normal showed a higher intake of fruits and vegetables than people who slept little or long in all fruit and vegetable subgroups
With these responses, three categories of sleep duration were established: short (less than 7 hours/day; 21%), normal (7-9 hours/day; 76.1%) and long (9 or more 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 heavy sleepers the average duration was 10.1 hours. The majority of participants (61.7%) classified themselves as having 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 a study covariate, noting that many studies have not included them as potential confounders. However, some research shows that they can influence dietary behaviors. “Studies have shown that nocturnal chronotypes are often associated with unhealthy dietary behaviors, including a propensity for obesity-related eating habits,” the researchers state:
The results revealed that people who slept what is considered normal showed a higher intake of fruits and vegetables than people who slept little or long in all fruit and vegetable subgroups. However, the intake of different types of fruits and vegetables yielded variable results. “In the vegetable subgroup, significant differences were observed in the consumption of leafy green vegetables, root vegetables, and fruit vegetables (e.g., tomatoes, cucumbers) between short and normal sleepers,” the researchers explain.
“Similarly, between normal sleepers and long sleepers, significant differences were again seen for leafy greens and fruit vegetables. However, for other fresh and canned vegetables such as cabbage, mushrooms, onion, peas and beans, no significant differences were observed.
“In the fruit subgroups, a significant mean difference in the consumption of berries and other fresh and canned fruits was observed between short and normal sleepers, conversely, between short and normal sleepers, the only significant difference was observed in the consumption of apples”.
The researchers also noted that sleep duration categories might indicate, to a lesser extent, expected levels of fruit and vegetable intake. This aligns with the results of a published in 2023 in International Journal of Behavioral Nutrition and Physical Activity which found a decrease in fruit and vegetable intake among adolescents the day after a short night of sleep. This new study also found that chronotypes play a minimal role in the connection between fruit and vegetable intake and sleep duration. The 2023 study found no link between fruit and vegetable intake and chronotypes.
Researchers note that, in general, lower intake of certain fruits and vegetables is related to short and long sleep duration. They recommend more specific work in this area to improve knowledge. “Specific interventions that focus on subgroups [de frutas y verduras] with pronounced associations, such as leafy greens and fruit vegetables, can lead to impactful behavior change. “Additional research, and especially longitudinal studies, are needed to better understand these associations and their implications for public health, especially in regions with population structures and dietary patterns similar to those of Finland,” they conclude.
