A recent study by researchers from Ireland and the United States looked at how different sources of protein can affect sleep quality, trying to find out whether plant proteins are more beneficial than animal proteins or vice versa. Quality sleep is defined by experts as calm and refreshing, and it can be evaluated according to several parameters.

According to the results of this study, published in the European Journal of Clinical Nutrition, there is a clear connection between a certain type of protein and the way you sleep. Although the total amount of protein consumed does not have a significant effect on sleep, studies have shown that plant-based protein can provide important benefits, while animal-based protein can negatively affect sleep quality.

The researchers analyzed data from more than 98,000 participants (83,338 women and 14,796 men) from three different groups of US health professionals. The researchers assessed the participants’ diets, including protein intake, and monitored sleep quality using various measures such as sleep duration, time to sleep, sleep efficiency, and sleep disturbance.

Plant proteins improve the quality of sleep, animal proteins reduce it

The results showed that women who consumed more plant-based protein reported better sleep quality, while increased intake of animal protein, particularly processed red meat and poultry, was associated with worse sleep. In men, the relationship was not so clear, but significant benefits of animal protein consumption were not observed.

The analysis of types of meat gave a more detailed view. For example, eating unprocessed red meat negatively affected sleep quality in women, but no significant effects were observed in men. In contrast, processed meat and poultry were associated with poorer sleep quality in both sexes.

Interestingly, milk protein improved sleep quality in one of the cohorts. On the other hand, fish consumption had no significant effect on sleep quality.

Why vegetable proteins are better

One of the reasons why vegetable proteins have a positive effect on sleep, according to experts, is the content of tryptophan, an essential amino acid for the production of serotonin and melatonin, substances that help sleep. In addition, plant proteins provide an optimal ratio of tryptophan to other large neutral amino acids (LNAAs), thereby promoting the ability of tryptophan to cross the blood-brain barrier and reach the brain, where it can be converted into growth-promoting sleep hormones.

However, plant proteins may provide additional sleep benefits not only through their tryptophan content, but also through other nutrients. For example, many foods high in plant protein are also excellent sources of magnesium, an important mineral linked to quality sleep, muscle relaxation and stress reduction. Foods like legumes, nuts, seeds, and whole grains contain, in addition to protein and tryptophan, a rich mix of vitamins and minerals that can promote more restful sleep.

Vegetables are also rich in fiber, which is also good for sleep. A high fiber intake can improve digestion and help stabilize blood sugar levels throughout the night, preventing nighttime awakenings and promoting uninterrupted sleep.

In addition, plant proteins are often found in foods with increased content of phytonutrients and antioxidants. These bioactive compounds, such as flavonoids and carotenoids, reduce inflammation and fight oxidative stress that might otherwise disrupt circadian rhythms and sleep quality.

Another theory about the benefits of plant proteins focuses on their effect on the intestinal flora. Regular consumption of plant protein helps enrich and maintain a healthy gut microbiome, an important element in the synthesis and balance of neurotransmitters and hormones that regulate sleep cycles, such as serotonin and melatonin.

Conversely, diets high in animal protein can sometimes have a negative effect on sleep, possibly due to high levels of saturated fatty acids and cholesterol, which can negatively affect heart health and disrupt sleep. In addition, some animal proteins can stimulate the production of hormones and inflammatory compounds that disrupt the hormonal balance necessary for deep, restful sleep.

However, the researchers note that the relationship between diet and sleep is complex and that there are other factors that can affect sleep quality, such as overall diet quality, caffeine intake or stress.

What is sleep quality and how is it measured?

Quality sleep simply means good sleep, meaning sleep that is restful and restorative. According to the US National Sleep Foundation, sleep quality is different from sleep satisfaction, which refers to a more subjective assessment of how you feel about your sleep. The quality of sleep is more difficult to measure than the duration of sleep, but it is not entirely subjective. The guidelines provide an overview of sleep quality goals and include some individual and age differences. In general, four aspects are evaluated to measure sleep quality:

• 1. Sleep latency: measures the time it takes to fall asleep. If you fall asleep within 30 minutes or less after going to bed, it means you are sleeping well;
• 2. Waking during the night: Refers to how often you wake up during the night. Frequent night awakenings can disrupt sleep cycles and impair sleep quality. If you wake up only once or not at all, it means that you sleep well;
• 3. Awake: This measure indicates the amount of time you stay awake at night after you first fall asleep. People with high quality sleep stay awake for 20 minutes or less during the night;
• 4. Sleep efficiency: The time you actually spend sleeping while in bed is called sleep efficiency. This figure should ideally be 85% or more for optimal health benefits.

What does poor sleep quality mean?

Not surprisingly, poor sleep quality is characterized by opposite factors. If you take more than 30 minutes to fall asleep, if you wake up more than once during the night, or if you take more than 20 minutes to fall back asleep after waking up, your sleep quality is considered poor

You’ll probably feel tired the next day, even if you get the recommended 7-9 hours of sleep. It is important to note that there are certain individual and age differences in these factors. For example, with age, it is usual to wake up at night more often. As long as you can quickly fall asleep in place, it won’t affect your sleep.

How to improve the quality of sleep

In order to improve the quality of sleep, it is important to follow a healthy daily routine. Dr. Michaela Orosh, a primary care pediatrician with expertise in somnology, offered some tips:

• By waking up at the same time every day, you help maintain your circadian rhythm. Exposure to light immediately after waking up is also important, as natural daylight affects the body’s internal clock;
• It is useful to reduce the impact of blue light from device screens 1-2 hours before bedtime. A dark environment promotes the production of melatonin, a hormone necessary for restful sleep;
• Exercising at the same time every day and avoiding long periods of inactivity is important for sleep quality;
• It is important to separate the workplace from the resting place so that the bed is not associated with work stress or personal problems;
• Day and night activities must be clearly distinguished. With the onset of darkness, it is recommended to limit strenuous activities and relax by reading, meditating or watching movies.

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