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Health AI can tell if you are sleep deprived by listening to your voice. News Subscriber-only. Health The truth behind melatonin and why it may not help you sleep. Features Subscriber-only. Health Some doses of blue light from screens may not affect your sleep. News Free. Health The key to deeper sleep might be a high-protein diet.

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You can read our Cookie Policy here. Sleep is essential for function and survival and not getting enough can increase the risk of chronic health conditions including heart disease, depression and diabetes. A new study from Harvard Medical School suggests eating more protein may help.

A key process for sleep is suppressing sensory arousal, in essence, being able to block out the world around us. The exact mechanisms by which this occurs are not well understood.

The new paper outlines that information from different senses is processed through independent mechanisms as we sleep. Dragana Rogulja, an associate professor of neurobiology in the Blavatnik Institute at Harvard Medical School, identified a peptide that promotes sensory arousal suppression by genetically screening flies that were hard to wake.

Their team developed a system that delivered low, medium or high-intensity vibrations to sleeping flies, which enabled them to identify the flies that experienced the deepest sleep.

When more protein was included in the diet, more CCHa1 was produced by enteroendocrine cells in the gut. From the gut, CCHa1 travels to the brain, where it initiates dopaminergic signaling that supresses arousal. The team also showed that a higher protein diet in mice improved sleep quality, making the mice less likely to wake in response to mechanical disturbances.

Reference: Titos I, Juginović A, Vaccaro A, et al. A gut-secreted peptide suppresses arousability from sleep. doi: This article has been republished from the following materials. Note: material may have been edited for length and content.

For further information, please contact the cited source. I Understand. Could Adding More Protein to Your Diet Boost Sleep Quality? A new study suggests eating more protein may help.

We use cookies to provide you with a better experience. You can read our Cookie Policy here. Sleep is essential for function and survival and not getting enough can increase the risk of chronic health conditions including heart disease, depression and diabetes.

A new study from Harvard Medical School suggests eating more protein may help. A key process for sleep is suppressing sensory arousal, in essence, being able to block out the world around us.

The exact mechanisms by which this occurs are not well understood. The new paper outlines that information from different senses is processed through independent mechanisms as we sleep.

Dragana Rogulja, an associate professor of neurobiology in the Blavatnik Institute at Harvard Medical School, identified a peptide that promotes sensory arousal suppression by genetically screening flies that were hard to wake. Their team developed a system that delivered low, medium or high-intensity vibrations to sleeping flies, which enabled them to identify the flies that experienced the deepest sleep.

When more protein was included in the diet, more CCHa1 was produced by enteroendocrine cells in the gut. From the gut, CCHa1 travels to the brain, where it initiates dopaminergic signaling that supresses arousal. The team also showed that a higher protein diet in mice improved sleep quality, making the mice less likely to wake in response to mechanical disturbances.

Reference: Titos I, Juginović A, Vaccaro A, et al. A gut-secreted peptide suppresses arousability from sleep.

doi: Meta-analyses also showed no significant effect of increased protein intake on sleep outcomes number of studies for SQ, ST, SL, and SEff: 8, 8, 7, and 6, respectively , with very low certainty of evidence. However, results from sensitivity analyses, excluding high-risk studies, suggest a small effect on SQ in favor of high protein intake mean difference, Conclusion: This systematic review and meta-analysis indicate there is no clear relationship between increased protein intake and sleep.

However, the strength of the evidence is low and more randomized controlled trials that focus on this specific research question are warranted.

Systematic Review Registration: PROSPERO registration no. Keywords: dietary protein; protein intake; sleep duration; sleep latency; sleep onset; sleep quality.

Published by Oxford University Press on behalf of the International Life Sciences Institute. The dietary changes in carbohydrates also primarily affect rapid eye movement REM sleep Afaghi et al.

The researchers report that this drop in sleep at the start of the sleep cycle is connected to carbohydrate oxidation Sanlier and Sabuncular Accordingly, carbohydrate oxidation was found to be more elevated after consuming high-carbohydrate diets than after a high-fat diet, and carbohydrate oxidation was found to be lower during slow-wave sleep and higher during REM sleep.

Some researchers have shown that diets with high carbohydrates positively affect delaying sleep, and researchers have found that a diet rich in carbohydrates leads to a shorter latency time than a controlled diet.

Furthermore, those diets high in protein had less wakefulness Lindseth et al. Several studies showed that subjects with short sleep duration get more additional calories from refined carbohydrates or fat Grandner et al. It is believed that after consuming meals low in fat and high in carbohydrates, there is an upsurge in slow-wave sleep duration and a drop in the duration of sleep spent during the REM phase.

In this study, drinks with a high level of carbohydrates raised the tendency to sleep duration compared to those with a low level of carbohydrates Sanlier and Sabuncular The effect of some foods and drinks on sleep appears due to their content and amount consumed.

Foods that contain protein make it easier to fall asleep. Carbohydrates are responsible for a sense of ease and comfort by impacting the level of serotonin.

Foods that affect tryptophan availability are two of the most promising sleep-inducing foods in synthesizing serotonin and melatonin. Melatonin synthesis is initiated through the synthesis of 5-hydroxy-tryptophan from tryptophan by tryptophanhydroxylase.

Then serotonin is synthesized from 5-hydroxy-tryptophan by 5-hydroxy-tryptophan decarboxylase. Another study revealed a link between lack of sleep associated with eating energy-rich foods for example, foods high in fats and refined carbohydrates , insufficient consumption of vegetables and fruits, and irregular eating habits Sanlier and Sabuncular A cross-sectional study showed that dietary protein intake relates to sleep quality, period, and pattern.

Protein intake has a positive association with sleep period, and those who consumed less protein have more insomnia episodes than those who consumed more Zhou et al. One study studied the effect of a diet consisting of high carbohydrates, fat, and protein compared to a control diet consumed daily for four days.

The high protein diet lowered the number of awakenings compared to the control diet. The effect of macronutrients on sleep is demonstrated by tryptophan, the precursor to serotonin and a sleep-inducing agent.

High glycemic index carbohydrates can increase tryptophan turnover. So, foods with high glycemic indexes are expected to stimulate sleep by increasing tryptophan and serotonin levels in the brain. Different pathways metabolize tryptophan to serotonin, melatonin, and niacin in the brain. It is also known that sleep deprivation reduces inhibitory control, stimulates negative moods, and affects the hormones that regulate appetite Sanlier and Sabuncular A high glycemic index GI diet is linked to stroke, cancer, and some chronic diseases Yu, et al.

Tryptophan competes with large natural amino acids in transport to the brain, so this change in the ratio may increase tryptophan in the brain. It is possible to notice the increase of serotonin levels in the brain after consuming carbohydrates; this mechanism explains the observations that a high-glycemic-index diet aids the sleep cycle Afaghi et al.

Also, it has been shown that diets with a high GI content stimulate inflammatory immune responses and lead to a rotation of the gut microbiome that may have an excellent effect on sleep quality Zhou et al. The essential amino acid tryptophan has a direct and essential impact on brain neurotransmitters.

It functions as a precursor to melatonin and serotonin, which means it has a connection to improving sleep quality and regulating circadian rhythms, and it can be obtained from the diet Lindseth and Murray Moreover, tryptophan intake in breakfast may be required for enhancing sleep initiation due to a high amount of serotonin-synthesized plasma melatonin in the pineal gland, which is synthesized again in the pineal gland during the day after the breakfast is consumed for several hours Watson and Preedy A comparative study was conducted to assess the impact of tryptophan-enriched cereal intake on improving sleep and showed that it is a facilitating and effective tool to improve sleep Bravo, et al.

Although, an experimental study about the effect of light exposure and tryptophan-rich breakfast during the daytime on the secretion of melatonin at night was conducted on 40 males aged 22—31 years old and lasted for five days and four nights.

The results showed that bright light exposure and a tryptophan-rich breakfast during the daytime encouraged melatonin secretion at night Fukushige, et al.

Additionally, a study of 40 patients with insomnia who had received gamma-aminobutyric acid GABA , which is a bioactive amino acid, for four weeks reported declined sleep latency and improved sleep efficacy.

Glutamine is a nonessential amino acid involved in GABA synthesis and is considered a sleep inducer. Tyrosine is also a nonessential amino acid; its metabolite is norepinephrine.

However, the association between tyrosine supplementation and sleep quality must be well studied. Snacks rich in branched-chain amino acids BCAA are helpful for cirrhotic patients who do not have explicit encephalopathy but have sleep problems.

BCAA supplementation improves sleep trouble; amino acid supplementation without BCAA-induced sleep disturbance. BCAAs can work as psychotropic substances directly working on the central nervous system.

OSA and restless legs syndrome are also known as causes of sleep trouble in patients with chronic liver disease Watson and Preedy Dietary fat showed great importance in regulating the body system.

Several studies have shown the effect of different kinds of fat on the sleep—wake cycle. It has been proven for the first time that a high-fat diet affects the circadian cycle among mice.

The study was conducted on mice. Their objective was to show that alterations in diet affected the circadian clock. This study showed that mice on a high-fat diet had longer and higher activity levels, resulting in less sleep Kohsaka, et al. Similarly, a study on humans was conducted to determine whether there was an association between fat diet intake and sleep period.

A study was conducted in in Jiangsu, China, by collecting data through a national survey. It concluded that individuals with higher fat consumption had fewer hours to sleep less than seven hours and suffered decreased sleep duration Shi et al. On the contrary, a study has shown that individuals who consumed a high-fat diet had better sleep quality.

The study aimed to evaluate the relationship between serum fat on sleeping disturbances. A negative correlation was found between the fat concentrations and the level of sleep disturbances Irmisch et al. Even though previous studies showed positive and negative results regarding fat consumption, they claimed no relation between fat content in food and sleep Landström et al.

Saturated fatty acids SFAs have a particular effect on body weight and health conditions. It has been proven in many studies that SFAs are a risk factor for many diseases, mainly cardiovascular disease Sacks, et al.

Consuming sugars and saturated fat have been associated with short sleep duration and fewer recovery and ad libitum diets by the inpatient sleep interruption study Frank et al. However, studies examining the relationship between SFAs and sleep quality are rare—a randomized clinical trial of patients with 26 normal body weight adults on a controlled diet.

Cholesterol also affects sleep quality, as a study has shown that a high cholesterol-containing diet can cause non-restorative sleep Grandner et al. Although, more studies have shown that high and low cholesterol consumption can negatively affect the duration and quality of sleep Santana ; Gangwisch, et al.

Polyunsaturated fatty acids PUFA have a good reputation for health in general, and it is known that omega-3 PUFA helps prevent cardiovascular disease Aung, et al.

A previous study on hamsters examined the role of omega-3 regarding melatonin rhythms; the aim was to find the effect of an omega-3 PUFA deficit diet on melatonin levels. They concluded that deficiency in omega-3 PUFA caused a disturbance in sleep by affecting the melatonin rhythm Lavialle, et al.

Additionally, fatty acids have shown several effects on sleep quality. A clinical study about the association between fatty acids and sleep quality was conducted on 63 obese patients 54 male and 9 female aged 18 to The unsaturated fatty acid was positively correlated with total sleep time.

The study showed a positive effect of omega-3 PUFA on sleep quality among obese individuals with OSA. This study aimed to determine the relationship between sleep quality and gluteal adipose tissue fatty acids. On the other hand, a case report suggested the opposite regarding omega-3 PUFA.

The study claimed that high eicosapentaenoic acid EPA fish oil supplements are a possible cause of sleep disturbance in successfully depression-treated patients. Sleep disturbances were diminished once the supplements were stopped Blanchard and McCarter Table 1 summarizes some studies with various methods in different age groups that were conducted to examine the relationship between sleep quality and energy intake.

Micronutrient intake has additionally been suggested to affect sleep patterns Frank et al. Vitamins and minerals affect the quality of sleep and are interconnected to the effect on melatonin production.

Exogenous melatonin is safe and beneficial in enhancing quality and sleep—wake cycles Sanlier and Sabuncular Based on many studies, vitamin B12 and vitamin B12 thiamine have been consumed at higher levels in people who sleep regularly than those with insomnia.

Besides, several well-designed studies support valerian A herb that is mostly used to treat sleeping disorders, especially insomnia as an effective supplement for improving sleep patterns Watson and Preedy Pyridoxine deficiency is thought to increase the risk of mental disorders and disturb sleep.

Additionally, it is believed to reduce night-time leg cramps. Some minerals and vitamin deficiencies can disturb sleep Sanlier and Sabuncular The development of daytime neurocognitive impairment may be related to Vitamin D deficiency. It may advance the risk of developing OSA by promoting chronic rhinitis, decreased airway pressure, and enlarged adenoid tonsils.

More research is required to determine the complex relationship between regular sleep duration and vitamin D Watson and Preedy A double-blind clinical trial study with 89 adult participants with sleep disorders, aged between 20—year-old, divided into two groups: intervention with 50 unit of vitamin D supplement and placebo.

Moreover, vitamin C, found in citrus fruits and vegetables, protects the brain from the memory loss associated with sleep deprivation. Also, vitamin B6 pyridoxine is widely found in food items that act as an enzyme in hundreds of enzymatic reactions Zhao et al.

Iron plays a significant role in many enzymatic processes. Iron and tetrahydrobiopterin are tyrosine hydroxylase cofactors. Also, iron is associated with the functions of opioid peptides, GABA, and serotonin Partinen et al.

Several studies have reported that magnesium enhances melatonin secretion in the pineal gland by promoting the N-acetyltransferase activity of serotonin as the central enzyme in melatonin synthesis, which can enhance sleep quality. Lack of vitamins such as B vitamins or minerals such as magnesium might negatively impact sleep.

Physiologically, this relies on the synthesis impacts of melatonin and serotonin Sanlier and Sabuncular Table 2. The impact of PA on sleep duration and quality studies conflicted on this subject. Some concluded that PA positively affected relieving stress and improved sleep quality Hori et al.

In contrast, other studies have concluded negative results Choi and Sohng It is well known that PA affects sleep quality positively Benloucif, et al. Most people reported sleeping better if they did any activity during the day. Several studies have shown that people with medium to high PA levels had better sleep quality Benloucif, et al.

Moreover, A prospective open-label study has shown that there is evidence that daily walking was beneficial in improving subjective sleep quality in both active and inactive individuals. After four weeks of walking intervention, it was found that the Pittsburgh Sleep Quality Index PSQI had improved along with sleep duration and latency Hori et al.

A study examined whether exercise training improved sleep quality for adults and older adults with sleeping disorders. The study targeted adults over 40 years old with sleeping disorders using self-reported PSQI or polysomnography.

The study intervened with a formal aerobic or resistance training program. It was conducted significantly reduce sleep latency for the exercise group. However, the results did not differ in sleep efficiency, sleep disturbance, or daytime functioning Yang et al.

Although, a prospective open-label study concerning improving subjective sleep by walking intervention examined a sample of healthy workers and divided them into two groups; subjects without PA habits and subjects with PA habits. A walking intervention with a target of 10, steps every day for a month was completed.

PSQI measurements were administered twice, before and after the study. It also improved sleep latency and duration Hori et al. More studies were interested in finding a positive effect on subjective and objective sleep quality.

An experimental study aimed to observe the impact of a month moderate to intense PA intervention on subjective and objective sleep quality. A sample of 66 inactive participants aged 55 or older with mild to moderate sleeping problems was given a month program to increase their PA.

The study improved some subjective and objective sleep dimensions. However, a systematic study demonstrated in showed no effect of PA on sleep quality or quantity, and the researchers studied the latest eight years of publications. They reviewed and analyzed the selected researchers systematically and concluded 14 studies.

Comparing the PA and sleep quality was based on moderate to vigorous PA levels. They found that some studies had a negative result with no effect of PA on sleep quality.

They also concluded that PA could be a modifiable risk factor for improving sleep in further studies Wang and Boros Many studies have agreed upon the positive effect of PA on sleep quality.

However, negative results still existed. A study has shown no noticeable effect of PA on sleep quality. A floor-seated exercise program FSEP was implemented on 77 older adult participants. Sleep quality had no significant effects Choi and Sohng Studies showcasing the association between nutrition, sleep quality, and PA have been discussed in this review.

These associations were concerned with the positive and negative correlations that were regarded with those studies. Several studies examined the effect of macro- and micro-nutrients on sleep parameters. Some studies proved that there was a positive correlation between nutrient intake and quality of sleep.

Nutrients such as tryptophan-rich foods, antioxidants, melatonin, micronutrients, and fruits positively affect sleep quality. Moreover, the leading cause of sleep restriction was excessive energy intake. Specifically, short sleep duration was mainly correlated with excessive energy intake of carbohydrates and fat.

Nevertheless, to what extent diet can impact sleep remains to be seen. For this reason, some diet nutrients and models can be utilized as sleep modulators. More studies about the effect of eating habits and the timing of meals should be conducted to understand the precise impact of nutrition on sleep quality.

The relationship was as follows: wherever the exercise rate increased, the amount of sleep improved. However, some studies claimed that PA did not affect sleep enhancement. Those studies needed further investigation on their side. The primary strength comes from its focus on diet and PA as an intervention to enhance sleep quality by focusing on diet and PA intervention rather than searching broadly for all sleep quality interventions to enhance such as medication and other therapy.

It also benefits life quality, mental health, work performance, and social life. Moreover, no national study shows that the prevalence of sleep disorders in Saudi Arabia can be generalized.

The limitations of this work were the focus on the studies that involved adults as samples. The main gap found during the research process was the significant need for studies reporting the relationship between those three dimensions nutrition, PA, and sleep quality. There was even no questionnaire conducted to assess the relationship between the dimensions.

Moreover, there needed to be more clinical trials with restricted instructions and with accurate outcomes. This was a scoping review aimed at identifying the beadth and scope of research on the topic.

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