Association between diet and sleep quality: A systematic review

Efficacy of lifestyle medicine on sleep quality: A meta-analysis of randomized controlled trials

OBJECTIVES

Randomized controlled trials (RCTs) on the efficacy of multicomponent lifestyle medicine (LM) interventions for improving sleep quality have yielded inconsistent findings. This study marks the first meta-analysis to evaluate the efficacy of multicomponent LM interventions in improving sleep quality.

METHODS

We searched six online databases for RCTs that compared multicomponent LM interventions to an active or inactive control group in an adult population and assessed subjective sleep quality as a primary or secondary outcome using validated sleep measures at any post-intervention time-point.

RESULTS

A total of 23 RCTs with 26 comparisons involving 2534 participants were included in the meta-analysis. After excluding outliers, the analysis revealed that multicomponent LM interventions significantly improved sleep quality at immediate post-intervention (d = 0.45) and at short-term follow-up (i.e., <three months) (d = 0.50) relative to an inactive control group. Regarding the comparison with active control, no significant between-group difference was found at any time-point. No meta-analysis was conducted at the medium- and long-term follow-up due to insufficient data. Subgroup analyses supported that multicomponent LM interventions had a more clinically relevant effect on improving sleep quality in participants with clinical levels of sleep disturbance (d = 1.02) relative to an inactive control at immediate post-intervention assessment. There was no evidence of publication bias.

CONCLUSION

Our findings provided preliminary evidence that multicomponent LM interventions were efficacious in improving sleep quality relative to an inactive control at immediate post-intervention and at short-term follow-up. Additional high-quality RCTs targeting individuals with clinically significant sleep disturbance and long-term follow-up are warranted.

Time in Bed, Sleeping Difficulties, and Nutrition in Pregnant New Zealand Women

We consider the relationship between time in bed (TIB) and sleeping difficulties with demographic variables and nutrient intakes in the second (T2) and third (T3) trimester of pregnancy. Data were acquired from a volunteer sample of New Zealand pregnant women. In T2 and T3, questionnaires were administered, diets were obtained from one 24 h recall and three weighed food records, and physical activity was measured with the use of three 24 h diaries. In total, 370 women had complete information in T2 and 310 in T3. In both trimesters, TIB was associated with welfare or disability status, marital status and age. In T2, TIB was associated with work, childcare, education and pre-pregnancy alcohol consumption. There were fewer significant lifestyle covariates in T3. In both trimesters, TIB declined with increasing dietary intake, especially water, protein, biotin, potassium, magnesium, calcium, phosphorus and manganese. Adjusted for weight of dietary intake and welfare/disability, TIB declined with increasing nutrient density of B vitamins, saturated fats, potassium, fructose and lactose; and TIB increased with carbohydrate, sucrose and vitamin E. Subjective sleeping difficulties increased with the week of gestation, morning sickness severity, anxiety, dairy and saturated fat intake, and they decreased with fruit, vegetable and monounsaturated fat intake. The study highlights the changing influence of covariates throughout the pregnancy and corroborates several published findings on the relationship of diet and sleep.

Impact of COVID-19 on dietary intake, sleeping patterns and physical activity levels among Malaysian University students

OBJECTIVES

The COVID-19 pandemic has brought a significant impact on people's behaviour and lifestyles. Limited research has been conducted on the impact of COVID-19 on Malaysian university students' lifestyle modifications. This study aims to identify the impact of COVID-19 on dietary intake, sleeping patterns and physical activity levels among Malaysian university students.

METHODS

A total of 261 university students were recruited. Sociodemographic and anthropometric data were collected. Dietary intake was assessed using PLifeCOVID-19 questionnaire, sleep quality was assessed using Pittsburgh Sleep Quality Index Questionnaire (PSQI) while physical activity level was assessed using International Physical Activity Questionnaire-Short Forms (IPAQ-SF). SPSS was used to perform statistical analysis.

RESULTS

30.7% of the participants adhered to the unhealthy dietary pattern, 48.7% had poor quality of sleep and 59.4% engaged in low physical activity levels during the pandemic. Unhealthy dietary pattern was significantly associated with a lower IPAQ category (p=0.013), and increased time spent sitting (p=0.027) during the pandemic. Participants being underweight before the pandemic (aOR=2.472, 95% CI=1.358-4.499), increased takeaway meal consumption (aOR=1.899, 95% CI=1.042-3.461), increased snacking between meals consumption (aOR=2.989, 95% CI=1.653-5.404) and engaged in a low level of physical activity during pandemic (aOR=1.935, 95% CI=1.028-3.643) were the predictors of unhealthy dietary pattern.

CONCLUSIONS

The university students' dietary intake, sleeping patterns, and physical activity levels were impacted in different ways during the pandemic. Strategies and interventions should be developed and implemented to improve the dietary intake and lifestyle of the students.

Intake of ultra-processed foods and sleep-related outcomes: A systematic review and meta-analysis

The aim of this review article was to evaluate the association between the intake of ultra-processed foods and sleep-related outcomes through a systematic review and meta-analysis. Pubmed, LILACS, Scielo, Scopus, Embase, and Web of Science were searched on December 31, 2021, for studies that evaluated the association between ultra-processed foods and sleep-related outcomes (self-reported sleep duration and quality). Pooled odds ratios were assessed through a random-effects model; heterogeneity was evaluated using the I² statistic. Fifteen cross-sectional studies were included; 14 showed that the high intake of ultra-processed foods was statistically significantly associated with sleep-related outcomes (sleep duration and quality). In the crude analysis, compared with low intake, high intake of ultra-processed foods increased the odds of sleep-related outcomes, with increased odds among children and/or adolescents, and null results among adults. When adjusted for cofounders, we found statistically significant results for all ages. The high intake of ultra-processed foods was associated with sleep-related outcomes, with moderate credibility of the evidence. Longitudinal studies and clinical trials confirming these findings are necessary.

Many faces of sleep regulation: beyond the time of day and prior wake time

The two-process model of sleep regulation posits two main processes regulating sleep: the circadian process controlled by the circadian clock and the homeostatic process that depends on the history of sleep and wakefulness. The model has provided a dominant conceptual framework for sleep research since its publication ~ 40 years ago. The time of day and prior wake time are the primary factors affecting the circadian and homeostatic processes, respectively. However, it is critical to consider other factors influencing sleep. Since sleep is incompatible with other behaviors, it is affected by the need for essential behaviors such as eating, foraging, mating, caring for offspring, and avoiding predators. Sleep is also affected by sensory inputs, sickness, increased need for memory consolidation after learning, and other factors. Here, we review multiple factors influencing sleep and discuss recent insights into the mechanisms balancing competing needs.

Polyphenol-Rich Beverages and Mental Health Outcomes

Emerging evidence suggests that diets rich in plant-based foods and beverages may exert plausible effects on human health tackling the risk of chronic diseases. Although the data are promising for numerous outcomes, including cardiovascular diseases, the data on mental health are limited. The aim of this study was to investigate the association between individual polyphenol-rich beverages intake and mental health outcomes, such as perceived stress, depressive symptoms, and sleep quality, among adult individuals living in the Mediterranean area. The demographic and dietary characteristics of a sample of 1572 adults living in southern Italy were analysed. Multivariate logistic regression analyses, controlling for confounding factors, were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between individual polyphenol-rich and alcoholic beverages containing polyphenols and mental health outcomes. The multivariate model adjusted for background covariates and the Mediterranean diet showed that individuals with a moderate intake (up to 1 cup/glass per day) of coffee and tea were less likely to have high perceived stress (OR = 0.61, 95% CI: 0.45-0.84) and depressive symptoms (OR = 0.56, 95% CI: 0.39-0.80), respectively. Furthermore, regular coffee and moderate/regular red wine drinkers were less likely to have depressive symptoms (OR = 0.72, 95% CI: 0.54-0.95 and OR = 0.74, 95% CI: 0.54-0.99, respectively). No significant associations were retrieved for the intake of polyphenol-rich and alcoholic beverages and sleep quality. In conclusion, the results of the present study suggest that polyphenol-rich beverages may be associated with mental health, in terms of depressive symptoms and perceived stress. Nonetheless, further research exploring how the polyphenol-rich beverages impact brain health and what the optimal patterns of consumption are for different populations are warranted.

Sedentary behaviour and sleep quality

High-quality sleep is an important factor in sustaining health and improving well-being. Previous evidence has demonstrated the positive associations between increased physical activity and reduced sedentary behaviour (SB) with sleep quality. The substitutional relationships between SB, light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) need to be considered when examining how a particular behaviour may impact sleep quality. No studies, to our knowledge, have explored these substitutional relationships in middle-aged adulthood. Using an isotemporal substitution approach, this study examined the associations of replacing sedentary time with physical activity on sleep quality measures in a sample of middle-aged adults in Japan. Data from 683 adults aged 40-64 living in Japan were used. The average daily time spent in SB, LPA, and MVPA was objectively assessed by accelerometers. Two self-reported sleep quality measures were obtained using questionnaires, including rest by sleep and sleep quality. Multivariable linear regression models were used to assess the associations of SB, LPA, and MVPA with the sleep quality measures stratified by gender. We found that each 60 min unit of SB or LPA replaced with MVPA was favourably associated with rest by sleep among women (β = 0.16, 95% CI 0.07, 0.28, p < 0.001; β = 0.18, 95% CI 0.07, 0.32, p < 0.05, respectively). There were no significant associations between SB, LPA, and MVPA with sleep measures in men across all three models. These findings indicate that higher MVPA has a positive association with sleep quality in middle-aged women.

Overall diet quality and proinflammatory diet in relation to risk of obstructive sleep apnea in 3 prospective US cohorts

BACKGROUND

Inflammation-related mechanisms may be important in the development of obstructive sleep apnea (OSA), and diet plays a crucial role in modulating inflammation. Current epidemiologic evidence for the associations between dietary patterns and OSA risk is limited to cross-sectional studies.

OBJECTIVES

We investigated prospectively the associations of overall diet quality and proinflammatory diet with OSA risk.

METHODS

We followed 145,801 participants in the Nurses' Health Study (NHS) (2002-2012), NHS II (1995-2013), and Health Professionals Follow-up Study (1996-2012). Alternative Healthy Eating Index 2010 (AHEI) and Empirical Dietary Inflammatory Pattern (EDIP) scores were calculated based on validated FFQs administered every 4 y. Cox models were used to estimate HRs and 95% CIs.

RESULTS

We documented 8856 incident OSA cases during follow-up. In pooled analyses adjusted for potential confounders, higher diet quality (higher AHEI scores) was associated with lower OSA risk (HR comparing the highest with the lowest quintile of AHEI: 0.76; 95% CI: 0.71, 0.82; P-trend < 0.001), and higher dietary inflammatory potential (higher EDIP scores) was associated with significantly increased risk (HR comparing the highest with the lowest quintile of EDIP: 1.94; 95% CI: 1.81, 2.08; P-trend < 0.001). Additional adjustment for metabolic factors attenuated both associations. The association with AHEI score was no longer statistically significant (comparable HR: 0.98; 95% CI: 0.91, 1.05; P-trend = 0.54), whereas the association with EDIP score remained statistically significant (comparable HR: 1.31; 95% CI: 1.22, 1.41; P-trend < 0.001).

CONCLUSIONS

A healthier diet, particularly one with anti-inflammatory potential, was associated with lower OSA risk.

The association of meal glycemic index/load with quantitative and qualitative indicators of sleep: a systematic review

INTRODUCTION

We sought to systematically review the association between meal glycemic index or glycemic load and sleep indicators.

EVIDENCE ACQUISITION

PubMed, Scopus, Web of Science, and Embase were searched up to March 2021. Both observational and clinical trials studies, with both male and female participants of all ages, were included.

EVIDENCE SYNTHESIS

A total of 10 studies were included in this review; six with clinical trial and four with cross-sectional design. Among the six clinical trial, three studies indicated a significant effect of high glycemic index on sleep (two in young male athletes [N.=8 and N.=9] and one in adults [N.=8]), while three others failed to detect any significant effect (young males [N.=12], children [N.=8], toddlers [N.=56]). Among the cross-sectional studies, high glycemic index meals were associated with improved sleep duration or quality in two studies (594 toddlers and 1848 adults), however, contrastingly, were also associated with sleep disturbances (108 students and 53,069 postmenopausal women).

CONCLUSIONS

High glycemic index meals likely improve sleep onset latency in young males. For other indicators of sleep quality and other population groups, the results are equivocal. Most of the available studies were conducted in special population groups and were inadequately designed; whilst clinical trials were of short duration and small sample sizes. Therefore, further well-designed clinical trials are required before further definitive conclusions can be made.

Is adherence to the 24-Hour Movement Guidelines associated with Mediterranean dietary patterns in adolescents?

BACKGROUND

Multiple health-risk behaviours such as physical inactivity, excessive recreational screen time, and insufficient sleep have been independently and positively associated with poor adherence to the Mediterranean diet in adolescents. However, little is known about the combined association between 24-Hour Movement Guidelines (i.e., physical activity, screen time, and sleep duration) and adherence to the Mediterranean diet.

OBJECTIVE

The aim of the present study was to examine whether adolescents who meet all three 24-Hour Movement Guidelines report greater adherence to the Mediterranean diet, and the different foods that comprise it, compared to those who do not meet the three recommendations.

METHODS

In this cross-sectional study, 1391 Spanish adolescents (13.08 ± 0.85, 44.82% girls), aged 11-16 years, completed self-reported questionnaires on physical activity, recreational screen time, sleep duration and adherence to the Mediterranean diet. A binary logistic regression analysis was used to predict the likelihood of having an optimal adherence to the Mediterranean diet, as well as different food items, according to the meeting of the three 24-Hour Movement Guidelines. Covariates included were age, sex, socioeconomic status, and body mass index (z-score).

RESULTS

Adolescents who met all three 24-Hour Movement Guidelines obtained higher adherence to the Mediterranean diet than those who did not meet with the three recommendations (β = 1.33, 95% confidence interval [CI]: 0.81, 1.85, p < 0.001). In addition, those who met all three 24-Hour Movement Guidelines were more likely to consume a fruit and vegetables once a day, consume fish regularly, and eat cereal or grains for breakfast (all, p < 0.05), and less likely to consume commercially baked goods or pastries for breakfast and to eat sweets and candies several times a day (all, p < 0.001), compared to those who did not comply with the three 24-Hour Movement Guidelines.

CONCLUSION

Since meeting the three 24-Hour Movement Guidelines seems to be associated with Mediterranean diet eating patterns in adolescents, it seems necessary to promote these movement behaviours from the early stages of life.

Interaction between ultra-processed food intake and genetic risk score on mental health and sleep quality

PURPOSE

Mental health and sleep quality are associated with genetics and nutrient and energy intake. The present study examined the association between ultra-processed food (UPF) intake and genetic risk score (GRS) and their interactions on mental health and sleep quality in Iranian women.

METHODS

A cross-sectional study was conducted on 278 overweight and obese females aged between 18 and 56 years. According to the NOVA classification system, 37 food groups and beverages were collected using a 147-item semi-quantitative food frequency questionnaire (FFQ). The blood parameters of all participants were assessed. Mini-column kit (type G; Genall; Exgene) and the PCR-RFLP method were used to extract DNA and determine gene polymorphism, respectively. Three single nucleotide polymorphisms (SNPs), including Caveolin_1 (Cav_1), Melanocortin4 receptor (MC4R), and cryptochrome circadian regulator 1 (CRY1), were used to calculate GRS. The individual risk allele (0, 1, 2) for each SNP was calculated using the incremental genetic model.

RESULTS

After controlling for confounders, a significant interaction was found for depression (β = 0.026, 95% CI 0.003, 0.049, P = 0.028) and depression anxiety stress scales (DASS) score (β = 0.059, 95% CI 0.001, 0.117, P = 0.046) on the NOVA classification system and GRS.

CONCLUSIONS

The findings of this study showed a significant interaction between GRS and the NOVA classification system on mental disorders, including depression, DASS score and stress. There was also a significant relationship between the NOVA classification system and anxiety, DASS score, sleep quality and depression. Furthermore, a partially significant association was observed between GRS and stress.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Relationship between Dietary Inflammatory Index and Postpartum Depression in Exclusively Breastfeeding Women

(1) Background: Research has shown that chronic inflammation can increase the risk of depression. The dietary inflammatory index (DII) is a novel measure of dietary inflammation, which has been used to investigate the relationship between diet and mental disorders in adults. However, little research has been conducted to establish an association between dietary inflammation (as measured by DII) and postpartum depression (PPD) in exclusively breastfeeding women. (2) Methods: In this cross-sectional study, 293 women who were exclusively breastfeeding for 6 months or less were enrolled. The DII scores were evaluated using semi-quantitative Food Frequency Questionnaires (FFQ), and the Edinburgh Postpartum Depression Scale (EPDS) was used to measure depression levels of breastfeeding mothers during the six months following delivery. The participants were classified by tertiles, and the possibility of DII being associated with PPD was assessed by binary regression analysis. (3) Results: The average DII score was 2.32 ± 1.08, which ranged from -1.66 to 4.19. The rate of depression was 60.1%. Adjusted for potential risk factors such as age, educational level, occupational level, number of babies, number of caregivers, social support level, and sleep quality, the results showed that the lowest DII score was associated with a lower risk of PPD than the highest score (OR tertile Q₁ vs. 3 = 0.47, 95% CI: 0.24, 0.93, p = 0.030). (4) Conclusions: In exclusive breastfeeding women, the inflammatory potential of dietary intake seems to be related to depression. Interventions to improve diet quality might consider including a dietary component that aims to lower chronic systemic inflammation to prevent PPD. However, the relationship between DII and PPD among Chinese women remains to be demonstrated in a larger population.

Determinants of natural adult sleep: An umbrella review

BACKGROUND

Sleep has a major impact on health, which makes it a relevant topic for research and health practitioners. Research on sleep determinants, i.e. factors that positively or negatively influence sleep, is fragmented.

OBJECTIVE

The purpose of this umbrella review is to provide an overview of the current evidence on determinants of natural adult sleep.

METHODS

A comprehensive literature search was performed on determinants of sleep. Reviews and meta-analyses on natural adult sleep were included. Six electronic databases (PubMed, WoS, Embase, CINAHL, PsycInfo and Cochrane) were used for the search, last accessed September 2021. The quality of the selected articles was assessed using the AMSTAR2 tool. Results were categorized in four main categories: biological, behavioral, environmental and personal/socio-economical determinants.

RESULTS

In total 93 reviews and meta-analyses resulted in a total of 30 identified determinants. The impact of each determinant differs per individual and per situation. Each determinant was found to affect different sleep parameters and the relationship with sleep is influenced by both generic and specific moderators.

DISCUSSION

A comprehensive overview on relevant sleep determinants provides a practical and scientifically based starting point to identify relevant intervention approaches to secure or improve individual sleep quality. The difference in aggregation level of the determinants and in measurement methods are the major limitations of this umbrella review. Extending existing generic sleep hygiene rules with an overview of all types of potential determinants will enhance the awareness of the complexity and can be used to improve the effect of sleep interventions in health promotion.

TRIAL REGISTRATION

The umbrella review was registered with PROSPERO (registration ID CRD42020149648) https://www.google.com/search?client=firefox-b-d&q=CRD42020149648.

Do Sleep Disorders and Western Diet Influence Psoriasis? A Scoping Review

Western diet may trigger sleep disorders and vice versa, but their single and mutual effects on systemic inflammatory diseases (i.e., psoriasis) are far from being fully elucidated. At the same time, psoriatic patients display a great burden of sleep disorders and dysmetabolisms related to an unhealthy lifestyle (i.e., diet). These patients are also affected by a chronic disorder deeply modulated by environmental factors (i.e., sleep and diet) capable to influence drug-response and disease progression. Thus, we aimed to summarize the evidence in the literature that may highlight a potential link among psoriasis–diet–sleep in order to further promote a multidisciplinary approach to psoriatic patients in the scientific community.

Linking Depressive and Anxiety Symptoms with Diet Quality of University Students: A Cross-Sectional Study during the COVID-19 Pandemic in India

This study examines the association of depressive and anxiety symptoms with diet quality among university students while controlling for different demographic and other health and lifestyle factors. This cross-sectional study was carried out between April 2021 and June 2021 among a total of 440 (unweighted) university students. Diet quality was assessed using a 10-item mini-dietary assessment index tool. The depressive and anxiety symptoms of participants were measured using the validated Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder (GAD-7) scale, respectively. Multivariable logistic regression and mediation analyses were performed. In this study, 61.1% (95% CI: 56.6% to 65.7%) of university students' diet quality was good during the COVID-19 pandemic. Being a post-graduate student, an urban resident, having no depressive (AOR = 2.15, 95% CI: 1.20 to 3.84) and anxiety symptoms (AOR = 1.96, 95% CI: 1.07 to 3.59), no changes or improvement in appetite, and no changes in sleep duration were significantly associated with good diet quality among our study participants. Depressive and anxiety symptoms during COVID-19 had a significant effect on the diet quality of university students. Future public health policies need to be focused on improving the mental health and well-being of students particularly during pandemic situations to enhance their diet quality.

Association of Pyridoxal 5′-Phosphate with Sleep-Related Problems in a General Population

The evidence on the relationship of pyridoxal 5′-phosphate (PLP) with sleep-related problems is limited and controversial. Notably, there is a lack of studies on the general population and studies of the dose–response relationship. Therefore, we conducted a cross-sectional study to examine the associations between serum PLP concentration and sleep-related problems (sleep quality and sleep duration) in adults, using the data of the National Health and Nutrition Examination Survey 2005–2010. High-performance liquid chromatography (HPLC) was used to test PLP in blood samples. Sleep quality and sleep duration were based on self-reported data, with sleep quality categorized as sleep disorder, trouble falling asleep, waking up during the night, and daytime sleepiness. The primary analyses utilized logistic regression models and restricted cubic spline. Compared with the first quartile (Q1), the odds ratios (ORs) and 95% confidence intervals (CIs) of daytime sleepiness for the Q2 and Q3 of serum PLP concentrations were 0.76 (0.59–0.99) and 0.78 (0.62–0.98), respectively. The relationship was only significant for males. Furthermore, a non-linear dose–response relationship was observed between serum PLP concentration and the risk of daytime sleepiness. Compared with the normal sleep duration group, serum PLP concentrations were negatively associated with the risks of very short, short, and long sleep duration, with relative risk ratios (RRRs) of 0.58 (0.43–0.81) (Q4), 0.71 (0.61–0.83) (Q4) and 0.62 (0.34–0.94) (Q3), respectively. The average serum PLP concentrations were higher in people with normal sleep duration, suggesting a non-linear dose–response relationship. Our study indicated that serum PLP concentrations were negatively associated with daytime sleepiness, and this association may only exist in males. Moreover, it was also inversely related to abnormal sleep duration (very short, short, long) compared to normal sleep duration.

The emerging importance of tackling sleep-diet interactions in lifestyle interventions for weight management

Sleep habits are directly related to risk of obesity, and this relationship may be partly mediated through food choices and eating behaviour. Short sleep duration, impaired sleep quality and suboptimal sleep timing are all implicated in weight gain and adverse cardiometabolic health, at least partly mediated through their associations with diet quality. Short-term sleep restriction leads to increased energy intake, and habitually short sleepers report dietary intakes that indicate a less healthy diet compared with adequate sleepers. Evidence is emerging that sleep extension interventions in short sleepers may reduce intake of sugars and overall energy intake. Poor sleep quality, night shift work patterns and social jetlag are also associated with lower diet quality and consumption of energy-dense foods. Incorporating sleep advice into weight management interventions may be more effective than energy-restricted diets and exercise advice alone. However, there are a lack of intervention studies that aim to lengthen sleep, improve sleep quality or adjust irregular sleep timing to investigate the impact on dietary intakes and eating behaviour in participants aiming to lose weight or maintain weight loss. Finally, future research should take account of individual characteristics such as age, sex, life stage and changing working practices when designing combined lifestyle interventions including sleep behaviour change for health and well-being.

The Association between Diet and Sleep Quality among Spanish University Students

While it has long been recognized that diet is a leading behavioral risk factor for human health, recent scientific findings have also suggested that diet and sleep quality may be connected. The purpose of the present study is to evaluate the association between diet and sleep quality among a group of Spanish university students. To do so, a cross-sectional study of 868 students was carried out. Sleep quality was assessed using the Spanish version of the Pittsburgh Sleep Quality Index (PSQI), while diet was assessed using the Spanish Healthy Eating Index (SHEI). The study revealed a noteworthy rate of bad sleepers (51.6%) and students whose diet needed modifications (82.2%). Unhealthy eaters were more likely to have poor sleep quality (aOR = 4.20; CI 95%: 2.07-8.52). The unbalanced intake of vegetables (aOR = 1.63; CI 95%: 1.14-2.34), fruits (aOR = 4.08; CI 95%: 2.90-5.74), dairy products (aOR = 1.96; CI 95%: 1.41-2.72), lean meats (aOR = 1.82; CI 95%: 1.19-2.78), legumes (aOR = 1.43; CI 95%: 1.00-2.02), sweets (aOR = 1.60; CI 95%: 1.13-2.25) and sugary soft drinks (aOR = 1.46; CI 95%: 1.07-1.99) was associated with lower sleep quality.

The Impact of Dietary Factors on the Sleep of Athletically Trained Populations: A Systematic Review

Many athletic populations report poor sleep, especially during intensive training and competition periods. Recently, diet has been shown to significantly affect sleep in general populations; however, little is known about the effect diet has on the sleep of athletically trained populations. With sleep critical for optimal recovery and sports performance, this systematic review aimed to evaluate the evidence demonstrating that dietary factors influence the sleep of athletically trained populations. Four electronic databases were searched from inception to May 2022, with primary research articles included if they contained a dietary factor(s), an outcome measure of sleep or sleepiness, and participants could be identified as ‘athletically trained’. Thirty-five studies were included, with 21 studies assessed as positive quality, 13 as neutral, and one as negative. Sleep or sleepiness was measured objectively in 46% of studies (n = 16). The review showed that evening (≥5 p.m.) caffeine intakes >2 mg·kg−1 body mass decreased sleep duration and sleep efficiency, and increased sleep latency and wake after sleep onset. Evening consumption of high glycaemic index carbohydrates and protein high in tryptophan may reduce sleep latency. Although promising, more research is required before the impact of probiotics, cherry juice, and beetroot juice on the sleep of athletes can be resolved. Athletic populations experiencing sleep difficulties should be screened for caffeine use and trial dietary strategies (e.g., evening consumption of high GI carbohydrates) to improve sleep.

Fruit and vegetable intake and incident and persistent poor sleep quality in a rural ageing population in South Africa: longitudinal study

BACKGROUND

Fruit and vegetable intake may improve sleep.

AIMS

To assess the relationship between fruit and vegetable intake and sleep quality in a longitudinal study.

METHOD

We analysed longitudinal data from two consecutive population surveys of adults in Agincourt, South Africa (2014-2015 and 2018-2019).

RESULTS

In total, 331 of 2975 participants without poor sleep quality in Wave 1 (11.1%) had incident poor sleep quality in Wave 2, and 270 of 3546 participants who had poor sleep quality in Wave 1 (7.6%) had poor sleep quality in both Waves 1 and 2 (persistent poor sleep quality). The prevalence of poor sleep quality at baseline was 17.2%. In the fully adjusted model for people without poor sleep quality at baseline, higher fruit and vegetable consumption (≥5 servings/day) was positively associated with incident poor sleep quality among men (AOR = 1.43, 95% CI 1.51-2.01) but not among women (AOR = 1.09, 95% CI 0.78-1.46). Two or more servings of fruits were positively associated with incident poor sleep quality among men (AOR = 3.35, 95% CI 1.96-5.72) and among women (AOR = 1.84, 95% CI 1.15-2.94). No models among men and women showed a significant association between vegetable intake and incident poor sleep quality or between fruit and vegetable intake, vegetable intake and persistent poor sleep quality. Fruit intake (one serving) was positively associated with persistent poor sleep quality among men (AOR = 1.76, 95% CI 1.00-3.08) but not among women (AOR = 1.42, 95% CI 0.93-2.18).

CONCLUSIONS

Higher fruit and vegetable intake was independently associated with poorer sleep quality among men but not women, and higher fruit but not vegetable intake was associated with poorer sleep quality among both men and women.

Mediterranean Diet on Sleep: A Health Alliance

The Mediterranean diet is a plant-based, antioxidant-rich, unsaturated fat dietary pattern that has been consistently associated with lower rates of noncommunicable diseases and total mortality, so that it is considered one of the healthiest dietary patterns. Clinical trials and mechanistic studies have demonstrated that the Mediterranean diet and its peculiar foods and nutrients exert beneficial effects against inflammation, oxidative stress, dysmetabolism, vascular dysfunction, adiposity, senescence, cognitive decline, neurodegeneration, and tumorigenesis, thus preventing age-associated chronic diseases and improving wellbeing and health. Nocturnal sleep is an essential physiological function, whose alteration is associated with health outcomes and chronic diseases. Scientific evidence suggests that diet and sleep are related in a bidirectional relationship, and the understanding of this association is important given their role in disease prevention. In this review, we surveyed the literature concerning the current state of evidence from epidemiological studies on the impact of the Mediterranean diet on nighttime sleep quantity and quality. The available studies indicate that greater adherence to the Mediterranean diet is associated with adequate sleep duration and with several indicators of better sleep quality. Potential mechanisms mediating the effect of the Mediterranean diet and its foods and nutrients on sleep are described, and gap-in-knowledge and new research agenda to corroborate findings are discussed.

A web-based survey assessing perceived changes in diet, physical activity and sleeping behaviours in adults with type 1 and type 2 diabetes during the COVID-19 pandemic in the UK

Background

The COVID-19 pandemic may have contributed to poorer self-management (ie, diet, physical activity and sleep) of diabetes mellitus (DM), which might predispose individuals to more severe COVID-19 outcomes.

Objective

The first objective was to capture perceived changes in diet, physical activity and sleeping during the COVID-19 pandemic in adults with type 1 (T1DM) and type 2 diabetes mellitus (T2DM) in the UK. A second objective was to explore differences between individuals with DM compared with 'no' or 'other' health conditions.

Methods

Participants aged >18 years were selected by convenience. Individuals subscribed to the Diabetes.co.uk community were sent a web-based survey including questions about demographics and health, followed by 5-point Likert-type scale questions relating to lifestyle-related behaviours during the COVID-19 pandemic. Individuals were grouped by diagnosis of DM, 'other' or 'no' health condition and responses were compared.

Results

4764 individuals responded, with 2434 (51.3%) being female and 1550 (32.6%) aged 55-64 years. T2DM (2974; 62.7%), hypertension (2147; 45.2%) and T1DM (1299; 27.4%) were most frequently reported. Compared with T1DM, 'no' or 'other' health conditions, respondents with T2DM reported making a less conscious effort to get outside and exercise daily (p<0.001) and spending no time outdoors (p=0.001). Weight loss was more frequently reported in respondents with T2DM (p=0.005). More individuals with T2DM reported consuming convenience foods (p=0.012) and sugary foods (p=0.021), yet eating more fresh foods (p=0.001) and drinking less alcohol than normal (p<0.001). More individuals with T1DM and T2DM reported worse sleep quality (p=0.004).

Conclusions

Our study highlighted important differences in lifestyle by individuals with T1DM, T2DM, other and no health conditions in relation to the COVID-19 pandemic. Establishing surveillance systems and conducting repeated assessments are required to analyse how the situation shifted over time and whether adverse collateral effects of the pandemic were sustained in those with chronic health conditions.

A greater modified Mediterranean diet score is associated with lower insomnia score among adolescent girls: a cross-sectional study

Background

Previous studies has shown that a low quality diet is related to sleep disorders. A Mediterranean diet is considered to be a high quality diet and has been shown to have beneficial effects on overall health. Thus, the aim of our study was to investigate the association between adherence to Mediterranean dietary pattern and insomnia score among adolescent girls.

Methods

The data for 733 adolescent girls between 12–18 years old was assessed in this cross-sectional study. A 147 item-food frequency questionnaire was used to assess dietary intake. A modified model of Mediterranean diet score was calculated that ranged from 0–9 points. A validated version of Insomnia Severity Index questionnaire was used to assess insomnia. To explore the association between modified Mediterranean (mMED) diet score and insomnia, linear regression was conducted in crude and adjusted models (energy intake adjustmet in Model I, further adjustments were performed for physical activity, father’s and mother’s education in Model II and full adjusted model adjusted for age, body mass index percentiles, and abdominal obesity).

Results

A significant inverse association between mMED diet score and insomnia score was observed using a crude model (β = -0.091, 95% confidence interval (CI): -0.392 to -0.046); P-value = 0.013) and also after adjustment for confounding factors in Model I (β = -0.098, CI: -0.423 to -0.045; P = 0.015), Model II (β = -0.092, CI: -0.410 to -0.029; P-value = 0.024), Model III (β = -0.082, CI: -0.385 to -0.006); P = 0.044).

Conclusion

There was an inverse relationship between adherence to the mMED diet score and insomnia level among Iranian adolescent girls. Prospective studies are needed to confirm these results and clarify whether a causal relationship exists.

Food consumption according to the level of processing and sleep quality during the COVID-19 pandemic

BACKGROUND AND AIMS

Consumption of ultra-processed foods is negatively associated with health outcomes, however, the contribution to sleep quality is limited. Therefore, the objective of this study was to evaluate the association between food intake by frequency and degree of processing and sleep quality in adults during the covid-19 pandemic.

METHODS

Population-based survey of adults from October to December 2020 in the Iron Quadrangle region, Brazil. The exposure variable was a food intake score that considered the frequency of consumption and food processing degree. The total score ranged from 0 (best) to 48 points (worst food quality), categorized into quartiles. Furthermore, we also evaluated whether individuals replaced their lunch and/or dinner based mostly on fresh/minimally processed foods for ultra-processed foods, for five or more days in the week. The outcome variable was sleep quality assessed with the Pittsburgh Sleep Quality Index. We constructed a contrasting directed acyclic graph (DAG) model to estimate the adjusted odds ratio of the association between score eating and sleep, by logistic regression.

RESULTS

Most of the 1762 individuals evaluated had poor sleep quality (52.5%). The minimum and maximum food scores were 0 and 30 points (mean 9.16; 95% CI 8.50, 9.81). The higher values of the score corresponded to lower consumption of fresh and minimally processed foods and higher consumption of ultraprocessed foods. In multivariate analysis, individuals in the third food consumption score had 71% greater odds of poor sleep quality (OR = 1.71; 95% CI: 1.03, 2.85) and in the fourth quartile 144% greater odds (OR = 2.44; 95% CI: 1.32, 2.44). Besides, replacing the dinner meal with ultra-processed foods five days or more in the week was also associated with poor sleep quality (OR = 2.01; 95%CI: 1.14, 3.57).

CONCLUSION

Higher consumption of ultra-processed foods concomitant with lower consumption of fresh and minimally processed foods is associated with a higher chance of poor sleep quality.

The Combined Influences of Exercise, Diet and Sleep on Neuroplasticity

Neuroplasticity refers to the brain's ability to undergo structural and functional adaptations in response to experience, and this process is associated with learning, memory and improvements in cognitive function. The brain's propensity for neuroplasticity is influenced by lifestyle factors including exercise, diet and sleep. This review gathers evidence from molecular, systems and behavioral neuroscience to explain how these three key lifestyle factors influence neuroplasticity alone and in combination with one another. This review collected results from human studies as well as animal models. This information will have implications for research, educational, fitness and neurorehabilitation settings.

Consumo de alimentos açucarados e qualidade do sono no primeiro ano de vida

Objetivo: investigar a duração do sono (DS), a frequência de despertares noturnos (DN) e o consumo de alimentos açucarados no primeiro ano de vida e verificar a associação entre o consumo desses alimentos e a má qualidade do sono. Métodos: a população do estudo foi composta de 179 crianças integrantes de uma coorte de nascimentos de Rio Largo-AL. As mães foram questionadas sobre a oferta regular de alimentos açucarados (açúcar/farinhas de cereais instantâneas com açúcar/bebidas açucaradas/doces) e o sono foi investigado pelo questionário traduzido e validado Brief Infant Sleep Questionnaire. Foram considerados indicadores de má qualidade do sono DS<12h e DN>2. Os testes de qui-quadrado de Pearson e exato de Fisher foram adotados para verificar associações entre o consumo de açucarados e a má qualidade do sono aos seis e 12 meses (p<0,05). Resultados: mais da metade das crianças apresentou DS<1 2h (60,3%) e cerca de ¼ DN>2. O consumo regular de pelo menos uma das categorias de açucarados foi verificado entre 50,6, 91,1 e 100% das crianças aos três, seis e 12 meses de idade, respectivamente. Não foram encontradas associações entre o consumo desses alimentos e os indicadores de má qualidade de sono. Conclusão: o consumo de açucarados e a má qualidade de sono foram frequentes em nosso estudo, no entanto, não se identificou associação entre as variáveis. Mais investigações são necessárias para elucidar como o sono e a alimentação se inter-relacionam e se potencializam mutuamente como fatores determinantes do crescimento e desenvolvimento de lactentes.

The Association Between Frequent Sugar-Sweetened Beverage Intake and Sleep Duration in School Children: A Cross-Sectional Study

Background

Higher consumption of sugar-sweetened beverages (SSBs) maybe association with children's sleep pattern. However, few studies have considered this association in Asia, especially in school children. This study investigated the relationship between children's consumption frequency of such beverages and their sleep duration.

Methods

Participants aged 6–12 years were analyzed from two survey data in 2012 and 2013–2016 Nutrition and Health Surveys in Taiwan. A total of 2,628 participants were included in the analysis (2012, N = 1,267; 2013–2016, N = 1,361). Beverages weekly consumption were divided into low and high intake groups by medians cut-off points. The sleep variables were the sleep duration at night (including school days and weekends) and sleep debt. After controlling the confounders, the correlation between sugar-sweetened beverage consumption and sleep duration was examined using multinomial logistic regression analysis.

Results

The students slept for an average of 8.8 h on school days and 9.7 h on weekends. Relative to the low SSB intake group, the high intake group exhibited shorter sleep durations on school days (P < 0.001), greater sleep debt (P = 0.049). In logistic regression, high intake group were more likely to sleep for <8.5 h on school days (OR = 1.67, P = 0.002) and exhibit >2 h of sleep debt than low intake group (OR = 1.41, P = 0.022).

Conclusions

Children who had consumed sugar-sweetened beverages frequently slept for shorter durations at night on school days and exhibited greater sleep debt. The causal relationship was not clear. Nonetheless, these two factors are important in promoting children health.

A practical nutritional guideline to manage neuroendocrine neoplasms through chronotype and sleep

Chronotype is the attitude of subjects to carry out their daily activities mainly in the morning ("lark") or in the evening ("owl"). The intermediate chronotype is located between these two categories. It has been demonstrated that chronotype can influence the incidence, course and response to treatments of tumors. In particular patients diagnosed with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and evening chronotype are characterized by unhealthy lifestyle, obesity, metabolic syndrome, a worsen cardiometabolic profile, a poor prognosis with a progressive disease and the development of metastasis. In addition, evening chronotype has been associated with sleep disturbances, which in turn have been related to tumor development and progression of tumors. There is a strict connection between sleep disturbances and NENs because of the hyperactivation of proangiogenic factors that caused aberrant neoangiogenesis. A nutritional tailored approach could represent a tool to align subjects with evening chronotype to physiological biological rhythms based on the properties of some macro and micronutrients of being substrate for melatonin synthesis. Thus, we aimed to provide an overview on the association of chronotype categories and sleep disturbances with NENs and to provide nutritional advices to manage subjects with NENs and these disturbances of circadian rhythm.

Recent advances in the utilization of tea active ingredients to regulate sleep through neuroendocrine pathway, immune system and intestinal microbiota

Sleep disorders have received widespread attention nowadays, which have been promoted by the accelerated pace of life, unhealthy diets and lack of exercise in modern society. The chemical medications to improve sleep has shown serious side effects and risks with high costs. Therefore, it is urgent to develop efficient nutraceuticals from natural sources to ensure sleep quality as a sustainable strategy. As the second most consumed beverage worldwide, the health-promoting effects of tea have long been widely recognized. However, the modulatory effect of teas on sleep disorders has received much less attention. Tea contains various natural sleep-modulating active ingredients such as L-theanine (LTA), caffeine, tea polyphenols (TPP), tea pigments, tea polysaccharides (TPS) and γ-aminobutyric acid (GABA). This review focuses on the potential influence and main regulating mechanisms of different tea active ingredients on sleep, including being absorbed by the small intestine and then cross the blood-brain barrier to act on neurons in the brain as neurotransmitters, manipulating the immune system and further affect sleep-wake cycle by regulating the levels of cytokines, and controlling the gut microbes to maintain the homeostasis of circadian rhythm. Current research progress and limitations are summarized and several future development directions are also proposed. This review hopes to provide new insights into the future elucidation of the sleep-regulating mechanisms of different teas and their natural active ingredients and the development of tea-based functional foods for alleviating sleep disorders. HighlightsNatural sleep-modulating active ingredients in tea have been summarized.Influences of drinking tea or tea active ingredients on sleep are reviewed.Three main regulating mechanisms of tea active ingredients on sleep are explained.The associations among nervous system, immune system and intestinal microbiota are investigated.The potential of developing delivery carriers for tea active ingredients is proposed.

The Relationship Between Dietary Intake and Sleep Quality in Endurance Athletes

Many endurance athletes have poor sleep quality which may affect performance and health. It is unclear how dietary intake affects sleep quality among athletes. We examined if sleep quality in endurance athletes is associated with consumption of fruit, vegetables, whole grains, dairy milk, and caffeinated beverages. Two hundred thirty-four endurance athletes (39.5 ± 14.1 year) participated in a survey. Participants provided information on demographics, anthropometry, sleep behavior and quality, and dietary intake via questionnaires. Sleep quality was assessed using the Athlete Sleep Screening Questionnaire (ASSQ) with a global score (ASSQ-global) and subscales including sleep difficulty (ASSQ-SD), chronotype (ASSQ-C), and disordered breathing while sleeping (ASSQ-SDB). A general linear model (GLM), adjusted for age, body mass index, sleep discomfort, sleep behavior, gender, race, and ethnicity, showed that higher caffeinated beverage intake was related to poorer global sleep quality (p = 0.01) and increased risk for disordered breathing while sleeping (p = 0.03). Higher whole grain intake was associated with a morning chronotype and lower risk for sleep issues (p = 0.01). The GLM did not reveal a relationship between sleep quality and dairy milk, fruit, and vegetable intake. In conclusion, caffeinated beverages and whole grain intake may influence sleep quality. This relationship needs to be confirmed by further research.

Perceptions of neighborhood dangerousness and changes in sleep quality during the COVID-19 pandemic: Assessing the mediating role of changes in health behaviors

Numerous studies have demonstrated that neighborhood context contributes to variations in morbidity and mortality. This body of work includes a burgeoning literature that links adverse neighborhood characteristics (e.g., neighborhood poverty and perceptions of disorder and dangerousness) with poorer sleep outcomes. During the COVID-19 pandemic, many neighborhoods exhibited socioeconomic downturns and escalations in crime and violence. The question is the extent to which these changes in neighborhood conditions have impacted the sleep quality of residents. In this paper, we use original survey data from the 2021 Crime, Health, and Politics Survey (CHAPS), a national probability sample of adults living in the U.S., to formally test whether changes in perceptions of neighborhood dangerousness during the pandemic are associated with sleep quality during the same period. Regression analyses show that while reports of a neighborhood becoming safer during the pandemic are associated with better sleep quality, reports of a neighborhood becoming more dangerous are associated with worse sleep quality. Mediation analyses also indicate that the association between increased neighborhood dangerousness and poorer sleep quality is partially explained by a concurrent deterioration in diet quality, but not increases in alcohol or cigarette consumption. We conclude with a discussion of the implications of our findings for research and policy on neighborhood context and sleep.

Higher HEI-2015 Scores Are Associated with Lower Risk of Sleep Disorder: Results from a Nationally Representative Survey of United States Adults

Whether there is an association between dietary quality and sleep disorder in American adults is unclear. We conducted this study to analyze whether dietary quality, using the Healthy Eating Index-2015 (HEI-2015) scores as the measure, was associated with self-reported sleep disorders. Data came from the National Health and Nutrition Examination Survey (2005–2014). Step-weighted logistic regression models were performed to explore the relationships between the HEI-2015 scores and sleep disorder. Weighted quantile sum regression model was used to identify the HEI-2015 components most strongly associated with sleep disorders. According to quartiles, HEI scores were categorized into inadequate (<25%), average (25–75%), and optimal (>75%). Compared to inadequate HEI status, average HEI status (OR: 0.961, 95%CI: 0.959–0.962) and optimal HEI status (OR: 0.913, 95% CI: 0.912–0.915) were associated with reduced risk of sleep disorder after multivariable adjustments. Greens and beans, added sugars, saturated fats, total vegetables and total protein foods were the top five important components for sleep disorders. Our results suggest that there is a statistically significant association between better dietary quality and reduced risk of sleep disorder among United States adults.

A retrospective cohort study on the association between poor sleep quality in junior high school students and high hemoglobin A1c level in early adults with higher body mass index values

BACKGROUND

Few epidemiological studies have been performed to clarify the association between glucose metabolism disorders in early adults (20 years old) and physiological and environmental factors, including body mass index (BMI) in junior high school days. Therefore, we examined the association between hemoglobin A1c (HbA1c) level and body size (BMI) in early adulthood and lifestyles, including sleep habits and BMI in junior high school days in Shika town, a small town in Japan, by conducting a retrospective cohort study.

METHODS

We examined the HbA1c levels and body size (BMI) of 99 early adults who turned 20 years old between 2016 and 2020 and were residing in Shika town, Ishikawa Prefecture. We obtained the information on lifestyles and living environment factors, including BMI, from a questionnaire survey conducted among the subjects during their junior high school days (13-15 years old) from 2009 to 2013.

RESULTS

No correlations were observed between the HbA1c levels and the BMI values of the early adults. A two-way analysis of covariance (with the HbA1c levels and BMI values of the early adults as main factors) of the body size and lifestyle habits of the junior high school students revealed that "sleep quality in junior high school" was significantly poorer in the high HbA1c group than in the low HbA1c group in the early adults with high BMI values only. This result was also supported by the logistic regression analysis result.

CONCLUSIONS

The present results indicate that poor sleep quality in junior high school was associated with the high HbA1c levels of the early adults with higher BMI values, which suggests that good sleep quality in junior high school prevents the development of hyperglycemia. However, the present study did not find any relationship between early-adult BMI and HbA1c level.

Longitudinal Associations of Adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Lifestyle Recommendations with Quality of Life and Symptoms in Colorectal Cancer Survivors up to 24 Months Post-Treatment

Post-treatment adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) lifestyle recommendations were associated with health-related quality of life (HRQoL), fatigue, and chemotherapy-induced peripheral neuropathy (CIPN) in colorectal cancer (CRC) survivors. In a prospective cohort among CRC survivors (n = 459), repeated home-visits were performed at 6 weeks, 6, 12, and 24 months post-treatment. Dietary intake, body composition, sedentary behaviour, and physical activity were assessed to construct a lifestyle score based on adherence to seven 2018 WCRF/AICR recommendations. Longitudinal associations of the lifestyle score with HRQoL, fatigue, and CIPN were analysed by confounder-adjusted linear mixed models. A higher lifestyle score was associated with better physical functioning and less activity-related fatigue, but not with CIPN. Adjustment for physical activity substantially attenuated observed associations, indicating its importance in the lifestyle score with regards to HRQoL. In contrast, adjustment for body composition and alcohol inflated observed associations, indicating that both recommendations had a counteractive influence within the lifestyle score. Our findings suggest that CRC survivors benefit from an overall adherence to the WCRF/AICR lifestyle recommendations in terms of HRQoL and fatigue, but not CIPN. Specific recommendations have a varying influence on these associations, complicating the interpretation and requiring further study.

The Dynamic Interplay of Healthy Lifestyle Behaviors for Cardiovascular Health

PURPOSE OF REVIEW

The recent rise in cardiovascular disease (CVD) deaths in the USA has sparked interest in identifying and implementing effective strategies to reverse this trend. Healthy lifestyle behaviors (i.e., healthy diet, regular physical activity, achieve and maintain a healthy weight, avoid tobacco exposure, good quality sleep, avoiding and managing stress) are the cornerstone for CVD prevention.

RECENT FINDINGS

Achieving all of these behaviors significantly benefits heart health; however, even small changes lower CVD risk. Moreover, there is interplay among healthy lifestyle behaviors where changing one may result in concomitant changes in another behavior. In contrast, the presence of one or more unhealthy lifestyle behaviors may attenuate changing another lifestyle behavior(s) (poor diet, inadequate physical activity, overweight/obesity, poor sleep quality, tobacco exposure, and poor stress management). It is important to assess all of these lifestyle behaviors with patients to plan an intervention program that is best positioned for adherence.

Exploring the Intersection Between Diet and Self-Identity: A Cross-Sectional Study With Australian Adults

OBJECTIVE

Diet-related self-identity, which includes components such as individuals' overall dietary pattern and food choice motivations, is a strong predictor of health behaviors. This study sought to assess the variation in dietary patterns reported by a sample of Australian adults and their associations with diet quality.

DESIGN

Cross-sectional survey.

PARTICIPANTS

Australian adults (n = 2,010) VARIABLES MEASURED: The main outcome measure was diet quality relative to the Australian Dietary Guidelines, measured by the Healthy Diet Score survey. Other outcomes captured included dietary patterns (eg, unrestricted, vegetarian, flexitarian, or ketogenic diets), diet-related self-identity constructs (centrality, prosocial motivation, personal motivation, and strictness), and sociodemographic characteristics (eg, age, sex, and education level).

ANALYSIS

Data were analyzed descriptively, and ordinary least squares regression was performed to identify significant predictors of diet quality.

RESULTS

Eighteen unique dietary patterns were reported. These were classified into 3 categories on the basis of the degree of restriction of core food groups. Diets based on restriction of animal protein were associated with the highest diet quality, including the highest consumption of fruits, vegetables, and whole grains, whereas restriction of other foods was associated with the poorest diet quality. Unrestricted diets reported the highest consumption of discretionary food (high in saturated fat, salt, or added sugar). Finally, the regression analysis found that diet quality was significantly predicted by dietary pattern and diet-related self-identity constructs (F[8, 1974] = 54.952; P < 0.0001; adjusted R² = 0.179).

CONCLUSIONS AND IMPLICATIONS

Dietary pattern and diet-related self-identity constructs are key determinants of diet quality. This has implications for future interventions, including that programs and messages could be tailored to ensure they align with the target population's self-identity and overall dietary patterns.

The Role of Dietary Inflammatory Index on the Association Between Sleep Quality and Long-Term Cardiovascular Risk: A Mediation Analysis Based on NHANES (2005-2008)

OBJECTIVE

People with poor sleep quality have higher risk of cardiovascular disease (CVD), and one potential mechanism of CVD is chronic inflammation. The aim of this study was to investigate the role of dietary inflammation in the relationship between sleep quality and CVD risk.

METHODS

This study involved 5594 participants from the National Health and Nutrition Examination Survey (NHANES) in 2005-2008. Sleep quality, dietary inflammation, and 10-year CVD risk were evaluated via the Pittsburgh Sleep Quality Index (PSQI), the Energy-adjusted Dietary Inflammatory Index (E-DII), and the Framingham Risk Score (FRS), respectively. We used generalized additive model (GAM) and mediation analysis to investigate the relationship among sleep quality, 10-year CVD risk, and E-DII.

RESULTS

PSQI had a non-linear relationship with 10-year CVD risk (P < 0.001). Meanwhile, among the participants with poor sleep quality, PSQI was positively associated with increased 10-year CVD risk (P < 0.001) and E-DII (P < 0.001). Furthermore, the association between sleep quality and CVD risk was partially mediated by E-DII, and the mediated proportion was 14.6%, and the mediating effect of E-DII varied in different gender and age groups. However, in the subjects with good sleep quality, the association among PSQI, E-DII, and 10-year CVD risk was not existed.

CONCLUSION

Ten-year CVD risk could be reduced by controlling the intake of inflammatory food, especially for whom with sleep disorders. In general, the reduction of inflammatory diet could weaken the effect of sleep disorders on the CVD risk.

Flight attendant occupational nutrition and lifestyle factors associated with COVID-19 incidence

In the era of COVID-19, essential workers are plagued with unforeseen and obfuscated challenges. Flight attendants are a unique subgroup of essential workers who face a multitude of health risks attributed to occupational exposures that are accentuated by the COVID-19 pandemic. Such risks can be ameliorated with strategies that target factors which enhance COVID-19 risk, including modifiable factors of diet and lifestyle. The aim of this cross-sectional study is to detect occupational dietary and lifestyle factors which could increase COVID-19 incidence amongst flight attendants. To identify potential risk factors, a questionnaire was administered to eighty-four flight attendants and examined the participants’ diet and lifestyle, and COVID-19 incidence. Descriptive statistics and logistic regression indicated that the participants’ perceived dietary quality at work (p = 0.003), sleep disruptions which impacted their consumption of a healthy diet (p = 0.013), job tenure (OR: 0.67, 95% CI: 0.46:0.98) and frequency of reported cold/flu (OR: 1.49, 95% CI: 1.014–2.189) were all factors associated with confirmed/suspected COVID-19 incidence. This study also revealed that a lack of infrastructure for food storage and time limitations are considerable occupational barriers for flight attendants to consume healthy foods. Additional investigation can further elucidate these relationships and related solutions to mitigate COVID-19 risk in the future.

Longitudinal and cross-sectional associations between the dietary inflammatory index and objectively and subjectively measured sleep among police officers

Police officers experience exposures associated with increased inflammation, such as the stress associated with shiftwork and poor-quality diet, both of which have been shown to affect sleep duration and quality. This study examined the longitudinal and cross-sectional effects of the Energy-density Dietary Inflammatory Index (E-DII™) on objectively and subjectively measured sleep among police officers. Data were derived from the Buffalo Cardio-Metabolic Occupational Police Stress Cohort (n = 464 at baseline), with longitudinal data collected from 2004 to 2019. A food frequency questionnaire obtained estimated dietary intake from which E-DII scores were calculated. Dependent variables were objectively (Micro Motion Logger Sleep Watch™) and subjectively (Pittsburgh Sleep Quality Index) measured sleep quality and quantity. The analyses included a series of linear mixed-effects models used to examine cross-sectional and longitudinal associations between the E-DII and sleep quantity and quality. Cross-sectionally, more pro-inflammatory diets were associated with higher wake-after-sleep-onset but improved subjective sleep quality. In models accounting for both longitudinal and cross-sectional effects, for every 1-unit increase in the E-DII scores over time (representing a pro-inflammatory change), wake-after-sleep-onset increased by nearly 1.4 min (p = 0.07). This result was driven by officers who primarily worked day shifts (β = 3.33, p = 0.01). Conversely, for every 1-unit increase in E-DII score, the Pittsburgh Sleep Quality Index global score improved. More pro-inflammatory diets were associated with increased wake-after-sleep-onset, an objective measure of sleep quality. Intervention studies to reduce dietary inflammatory potential may provide greater magnitude of effect for changes in sleep quality.

Sleep Characteristics According to Gender and Age Measured by Wrist Actigraphy

The sleep/wake rhythm is one of the most important biological rhythms. Quality and duration of sleep change during lifetime. The aim of our study was to determine differences in sleep efficiency, movement, and fragmentation during sleep period between genders and according to age. Sleep period was monitored by wrist actigraphy under home-based conditions. Seventy-four healthy participants-47 women and 27 men participated in the study. The participants were divided by age into groups younger than 40 years and 40 years and older. Women showed lower sleep fragmentation and mobility during sleep compared to men. Younger women showed a higher actual sleep and sleep efficiency compared to older women and younger men. Younger men compared to older men had a significantly lower actual sleep, lower sleep efficiency and significantly more sleep and wake bouts. Our results confirmed differences in sleep parameters between genders and according to age. The best sleep quality was detected in young women, but gender differences were not apparent in elderly participants, suggesting the impact of sex hormones on sleep.

The Association of Self-Reported Iron and Vitamin D Levels on Sleep Quality and Pain Perception in a Subset of Saudi Population

Background and Aims

There has been a rising concern regarding the relationship of iron levels, vitamin D, and consumption of multivitamins on pain perception and sleep quality. The purpose of this study is to shed light on these connections in hopes of enhancing quality of sleep.

Methods

A cross-sectional analysis was used, and data collection was based on close-ended online questionnaire created on Survey Monkey. The survey included an operator designed questionnaire, questions from both the Brief Pain Inventory and Sleep Quality questionnaires. The targeted population was participants who were medically fit, non-pregnant Saudi citizens aged between 25 and 55 years.

Results

Prior to the COVID-19 crisis, data were collected during the months of February and March 2020, with a grand total of 3127 participants, out of which 2774 responses were included. The outcome of the research revealed that diminished levels of vitamin D, and iron had a negative impact on sleep quality. In turn, poor sleep quality had a significant pain response.

Conclusion

This study reveals the detrimental role of vitamins on sleep, and their concurrent domino effect on pain.

Is there a relationship between the ketogenic diet and sleep disorders?

Sleep disorders are very often underestimated and, consequently, not treated with due priority. Common sleep disorders include insomnia disorders, sleep-related breathing disorders, central disorders of hypersomnolence, circadian rhythm sleep-wake disorders, sleep-related movement disorders, parasomnias, and other sleep disorders. The ketogenic diet (KD) is rich in fat, low in carbohydrates (CHO), and adequate in protein. The KD has shown several applications in treating medical conditions, such as epilepsy, neurodegenerative disorders, obesity with its comorbidities, and sleep disorders, with encouraging results. Therefore, the purpose of this review is to address the primary sleep disorders and their respective standard therapeutic approaches, analyse the effect of ketone bodies (KBs) on sleep homeostasis, and the effects of KD on sleep disorders and in particular on obstructive sleep apnoea (OSA) syndrome. The goal is to summarise the evidence existing up to now on the subject, to provide a starting point for further investigations.

Eating habits are associated with subjective sleep quality outcomes among university students: findings of a cross-sectional study

PURPOSE

This study investigated the relationships between eating habits and sleep quality among university students.

METHODS

In a cross-sectional study, university students completed a self-report questionnaire to assess eating habits and meal timing. We assessed subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI) questionnaire and examined the associations between eating habits and overall sleep quality and its components.

RESULTS

Four hundred ninety-eight students participated in the study. Students who used to skip breakfast, ate late-night snacks, and replaced meals with snacks were at 1.20 times, 1.24 times, and 1.25 times higher likelihood of having poor overall sleep quality, respectively. Multiple logistic regression analysis showed that skipping breakfast (r =  - 0.111, P = 0.007), late-night snacks (r =  - 0.109, P = 0.007), replacing meals with snacks (r =  - 0.126, P = 0.002), and irregular mealtimes (r =  - 0.094, P = 0.018) were the best correlates with poor sleep quality. After adjustment to demographic variables, replacing meals with snacks followed by skipping breakfast were the best independent associations with poor sleep quality by the PSQI.

CONCLUSIONS

Eating habits and meal timing were significantly associated with sleep quality. We speculate that healthy eating habits may lead to improved sleep quality and sleep components among university students.

The iMPROVE Study; Design, Dietary Patterns, and Development of a Lifestyle Index in Overweight and Obese Greek Adults

Background: Dietary and lifestyle habits constitute a significant contributing factor in the formation of anthropometric and biochemical characteristics of overweight and obese populations. The iMPROVE study recruited overweight and obese Greek adults and investigated the effect of gene–diet interactions on weight management when adhering to a six-month, randomized nutritional trial including two hypocaloric diets of different macronutrient content. The present paper displays the design of the intervention and the baseline findings of the participants’ dietary habits and their baseline anthropometric and biochemical characteristics. Methods: Baseline available data for 202 participants were analyzed and patterns were extracted via principal component analysis (PCA) on 69-item Food-Frequency Questionnaires (FFQ). Relationships with indices at baseline were investigated by multivariate linear regressions. A Lifestyle Index of five variables was further constructed. Results: PCA provided 5 dietary patterns. The “Mixed” pattern displayed positive associations with logBMI and logVisceral fat, whereas the “Traditional, vegetarian-alike” pattern was nominally, negatively associated with body and visceral fat, but positively associated with HDL levels. The Lifestyle Index displayed protective effects in the formation of logBMI and logGlucose levels. Conclusions: Dietary patterns and a Lifestyle Index in overweight and obese, Greek adults highlighted associations between diet, lifestyle, and anthropometric and biochemical indices.

Association of plant-based diet index with inflammatory markers and sleep quality in overweight and obese female adults: A cross-sectional study

BACKGROUND

Inflammation and sleep disturbances increase the risk of multiple diseases, including cardiovascular disease, type 2 diabetes and dementia. Since diet plays a significant role in inflammatory responses and sleep quality, this study aimed to investigate the association of a plant-based diet index (PDI) with sleep quality and inflammatory markers in overweight and obese women.

METHODS

390 overweight and obese women aged 18-48 years participated in this cross-sectional study. A validated food frequency questionnaire (FFQ) was used to create an overall PDI, healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI). Sleep quality was assessed by Pittsburgh Sleep Quality Index (PSQI). Higher scores on the PSQI were indicative of poor sleep. Anthropometric measurements and serum concentrations of high-sensitivity C-reactive protein (hs-CRP), interleukin 1 beta (IL-1β) and transforming growth factor-beta (TGF-β) were evaluated. Linear regression models were used to determine the association between exposure and outcomes.

RESULTS

After taking potential confounders into account, we found a significant inverse association between adherence to hPDI and hs-CRP (β = -0.14, 95% confidence interval [CI]: -0.22,0.06, P = .001) and a significant positive association between uPDI and hs-CRP (β = 0.13, 95% CI: 0.05,0.21, P = .001). Overall, PDI was significantly associated with TGF-β (β = 2.04, 95% CI: 0.54,3.55, P = .008). No association was detected between PDI indices and IL-1β. Higher adherence to uPDI was significantly associated with higher PSQI score (lower sleep quality) (β= 0.20, 95% CI:0.007,0.40, P = .04). A significant positive association was found between TGF-β (β = 0.05, 95% CI:0.005,0.10, P = .03) and hs-CRP (β = 0.32, 95% CI:0.02,0.62, P = .03) with PSQI.

CONCLUSION

Our findings indicated a significant association between adherence to a plant-based diet with inflammation and sleep quality in obese and overweight females. WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Sleep is an essential part of life, and sleep quality has a significant impact on individual well-being and performance. There is a bidirectional relationship between disturbed sleep and elevated levels of inflammatory markers. Diet plays a major part in sleep quality and its related health consequences. Plant-based diets are associated with lower risk of chronic diseases such as coronary artery disease (CAD), type 2 diabetes, obesity and reduced level of inflammation. WHAT DOES THIS ARTICLE ADD?: Adherence to a healthful plant-based diet is associated with lower level of hs-CRP, while adherence to an unhealthful plant-based diet is associated with higher concentrations of hs-CRP. Adherence to an unhealthful plant-based diet is associated with lower sleep quality.

Arousal-Inducing Effect of Garcinia cambogia Peel Extract in Pentobarbital-Induced Sleep Test and Electroencephalographic Analysis

Caffeine, a natural stimulant, is known to be effective for weight loss. On this basis, we screened the arousal-inducing effect of five dietary supplements with a weight loss effect (Garcinia cambogia, Coleus forskohlii, Camellia sinensis L., Irvingia gabonensis, and Malus pumila M.), of which the G. cambogia peel extract (GC) showed a significant arousal-inducing effect in the pentobarbital-induced sleep test in mice. This characteristic of GC was further evaluated by analysis of electroencephalogram and electromyogram in C57L/6N mice, and it was compared to that of the positive control, caffeine. Administration of GC (1500 mg/kg) significantly increased wakefulness and decreased non-rapid eye movement sleep, similar to that of caffeine (25 mg/kg), with GC and caffeine showing a significant increase in wakefulness at 2 and 6 h, respectively. Compared to that of caffeine, the shorter duration of efficacy of GC could be advantageous because of the lower possibility of sleep disturbance. Furthermore, the arousal-inducing effects of GC (1500 mg/kg) and caffeine (25 mg/kg) persisted throughout the chronic (3 weeks) administration study. This study, for the first time, revealed the arousal-inducing effect of GC. Our findings suggest that GC might be a promising natural stimulant with no side effects. In addition, it is preferential to take GC as a dietary supplement for weight loss during the daytime to avoid sleep disturbances owing to its arousal-inducing effect.