Mediterranean diet and chronotype: Data from Italian adults and systematic review of observational studies

Sleep and the Mediterranean diet: A systematic review and meta-analysis

We conducted the current systematic review and meta-analysis to critically review and synthesize available evidence regarding the association between sleep duration, sleep quality, and chronotype with the Mediterranean diet (MedDiet) among the general population using observational studies. Online databases, including PubMed, Scopus, and ISI Web of Science, were searched from the earliest available date until December 2024. We enrolled 62 studies with a total sample size of 328,493. The mean age and BMI of the participants in the enrolled studies ranged from 6.1 to 74.7 years and 18.1-32.1 kg/m2. Individuals with sufficient sleep duration (OR: 1.39; 95 % CI, 1.04, 1.85; P = 0.030; I2 = 97.89 %, PQ-test < 0.001), good-quality sleep (OR: 1.38; 95 % CI, 1.10, 1.73; P < 0.001; I2 = 93.83 %, PQ-test < 0.001), and earlier chronotype (OR: 1.74; 95 % CI, 1.21, 2.50; P = 0.002; I2 = 89.72 %, PQ-test < 0.001) had significantly increased odds of high MedDiet scores, compared to those with insufficient sleep duration, poor-quality sleep, and later chronotype, respectively. Our study revealed that sleep duration, sleep quality, and chronotype are lifestyle-related factors linked to MedDiet. However, more longitudinal studies and clinical trials are needed to investigate causality, mediating factors, and underlying mechanisms.

The impact of breakfast skipping on plasma glucose levels in non-diabetic individuals: gender-based differences and implications

Chrono-nutritional factors may play a significant role in glucose regulation and the risk of type 2 diabetes (T2D). We investigated the association between breakfast skipping (BS) and fasting plasma glucose (FPG) levels in a non-diabetic cohort of the ABCD project (nutrition, cardiovascular wellness and diabetes) representing the general population of Palermo, Italy Among the 623 participants included in the analysis, 118 individuals were identified as BS. In men, BS was associated with higher values of FPG (p < .05), glycated haemoglobin (p < .01), triglycerides (p < .05) and insulin (p < .005). Among women, no significant differences were observed between BS and non-skippers. Multivariate regression analysis confirmed that BS was an independent predictor of higher FPG levels in men (p < .01); waist circumference emerged as the primary predictor of FPG in women (p < .001). This study supports the importance of dietary habits in glycaemic control and T2D risk.

Impact of adherence to the Mediterranean diet on stroke risk

Stroke is a leading cause of morbidity and mortality worldwide, and dietary patterns have emerged as a significant modifiable factor in stroke prevention. The Mediterranean diet, characterized by high intake of fruits, vegetables, whole grains, nuts, olive oil, and fish, has been widely recognized for its cardiovascular benefits. However, its specific impact on stroke risk requires further elucidation. We conducted a comprehensive meta-analysis of 30 studies, including both cohort and case-control designs, to evaluate the relationship between adherence to the Mediterranean diet and the risk of stroke. A systematic search was performed across multiple databases, and a random-effects model was used to estimate pooled hazard ratios (HRs) with 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 statistic, and publication bias was examined through funnel plots and Egger's regression test. Additionally, trial sequential analysis was conducted to determine the adequacy of the sample size. The meta-analysis revealed a significant reduction in stroke risk among individuals adhering to the Mediterranean diet, with a pooled HR of 0.88 (95% CI: 0.84-0.91). Notably, a significant heterogeneity was detected (I2 = 34%). The Z-score plot from trial sequential analysis confirmed that the sample sizes were sufficient to draw definitive conclusions. However, a potential publication bias was identified. The case-control studies confirmed a highly significant effect (HR = 0.54, 95% CI: 0.4-0.73). The funnel plots in both settings hinted at the presence of a potential publication bias, supported by a significant Egger's test. Our findings provide robust evidence supporting the protective effect of the Mediterranean diet against stroke. Despite the presence of some heterogeneity and potential publication bias, the cumulative evidence suggests that promoting the Mediterranean diet could serve as an effective public health strategy for stroke prevention. Further research is recommended to explore the underlying mechanisms and to assess the diet's impact across diverse populations.

The Triad of Sleep, Immunity, and Cancer: A Mediating Perspective

The triadic interplay between sleep, immunity, and cancer represents a growing area of biomedical research with significant clinical implications. This review synthesizes the current knowledge on how sleep influences immune function, the immune system's role in cancer dynamics, and the direct connections between sleep patterns and cancer risk. After a comprehensive overview of the interrelationships among these three domains, the mechanisms of sleep in immune function are described, detailing how sleep regulates the immune system, the effects of sleep duration and quality on immune responses, and the underlying molecular and cellular mechanisms. Also, the complex relationship between immunity and cancer is explored, highlighting the immune system's role in cancer prevention and progression, immune surveillance, tumor microenvironment, and the implications of immunodeficiency and immune modulation on cancer risk. The direct connections between sleep and cancer are then described, presenting epidemiological evidence linking sleep patterns to cancer risk, biological mechanisms that influence cancer development, and the role of sleep disorders in cancer prognosis. The mediating role of sleep between immunity and cancer is highlighted, proposing hypothesized pathways, summarizing evidence from experimental and clinical studies, and evaluating the impact of sleep interventions on immune function and cancer outcomes. This review concludes by discussing the clinical implications and future directions, emphasizing the potential for sleep-based interventions in cancer prevention and treatment, the integration of sleep management in oncology and immunotherapy, and outlining a future research agenda. This agenda includes understanding the mechanisms of the sleep-immunity-cancer interplay, conducting epidemiological studies on sleep and cancer risk, assessing the impact of sleep management in cancer treatment protocols, exploring sleep and tumor microenvironment interactions, and considering policy and public health implications. Through a detailed examination of these interconnected pathways, this review underscores the critical importance of sleep in modulating immune function and cancer outcomes, advocating for interdisciplinary research and clinical strategies to harness this knowledge for improved health outcomes.

Impact of sleep on gastrointestinal cancer

Sleep problems have become a significant public health concern, affecting a large portion of the global population and have been linked to increased morbidity and mortality. The incidence of gastrointestinal (GI) cancers continues to rise, posing a substantial burden on healthcare systems worldwide. This editorial aims to delve into the impact of sleep on GI cancers, including esophageal, gastric, colorectal, hepatobiliary, and pancreatic cancer. Recent literature investigating the potential connections between GI cancers and sleep was reviewed. We considered aspects such as sleep duration, sleep disorders, and circadian rhythmicity, in order to explore the underlying mechanisms that can contribute to the development of GI cancers and propose avenues for future research.

Underrated aspects of a true Mediterranean diet: understanding traditional features for worldwide application of a "Planeterranean" diet

Over the last decades, the Mediterranean diet gained enormous scientific, social, and commercial attention due to proven positive effects on health and undeniable taste that facilitated a widespread popularity. Researchers have investigated the role of Mediterranean-type dietary patterns on human health all around the world, reporting consistent findings concerning its benefits. However, what does truly define the Mediterranean diet? The myriad of dietary scores synthesizes the nutritional content of a Mediterranean-type diet, but a variety of aspects are generally unexplored when studying the adherence to this dietary pattern. Among dietary factors, the main characteristics of the Mediterranean diet, such as consumption of fruit and vegetables, olive oil, and cereals should be accompanied by other underrated features, such as the following: (i) specific reference to whole-grain consumption; (ii) considering the consumption of legumes, nuts, seeds, herbs and spices often untested when exploring the adherence to the Mediterranean diet; (iii) consumption of eggs and dairy products as common foods consumed in the Mediterranean region (irrespectively of the modern demonization of dietary fat intake). Another main feature of the Mediterranean diet includes (red) wine consumption, but more general patterns of alcohol intake are generally unmeasured, lacking specificity concerning the drinking occasion and intensity (i.e., alcohol drinking during meals). Among other underrated aspects, cooking methods are rather simple and yet extremely varied. Several underrated aspects are related to the quality of food consumed when the Mediterranean diet was first investigated: foods are locally produced, minimally processed, and preserved with more natural methods (i.e., fermentation), strongly connected with the territory with limited and controlled impact on the environment. Dietary habits are also associated with lifestyle behaviors, such as sleeping patterns, and social and cultural values, favoring commensality and frugality. In conclusion, it is rather reductive to consider the Mediterranean diet as just a pattern of food groups to be consumed decontextualized from the social and geographical background of Mediterranean culture. While the methodologies to study the Mediterranean diet have demonstrated to be useful up to date, a more holistic approach should be considered in future studies by considering the aforementioned underrated features and values to be potentially applied globally through the concept of a "Planeterranean" diet.

Sleep Pathologies and Eating Disorders: A Crossroad for Neurology, Psychiatry and Nutrition

The intricate connection between eating behaviors and sleep habits is often overlooked in clinical practice, despite their profound interdependence. Sleep plays a key role in modulating psychological, hormonal and metabolic balance and exerting an influence on food choices. Conversely, various eating disorders may affect sleep continuity, sometimes promoting the development of sleep pathologies. Neurologists, nutritionists and psychiatrists tend to focus on these issues separately, resulting in a failure to recognize the full extent of the clinical conditions. This detrimental separation can lead to underestimation, misdiagnosis and inappropriate therapeutic interventions. In this review, we aim to provide a comprehensive understanding of the tangled relationship between sleep, sleep pathologies and eating disorders, by incorporating the perspective of sleep experts, psychologists and psychiatrists. Our goal is to identify a practical crossroad integrating the expertise of all the involved specialists.