Irene Gracia-Rubio

Shift work is associated with an increased risk of metabolic disorders, including type 2 diabetes, largely due to circadian misalignment, irregular meal patterns and suboptimal diet quality. Chrononutrition, which focuses on aligning nutrient intake with circadian rhythms, has emerged as a promising strategy to improve metabolic health. Protein intake plays a key role in glucose homoeostasis, and high-protein hypoenergetic diets have shown benefits in people with type 2 diabetes. However, the effects of higher evening protein intake in shift workers remain unclear. This trial aims to analyse the effect of three hypoenergetic diets differing in macronutrient composition and distribution throughout the day on glycaemic control, body composition and other secondary outcomes in shift workers with overweight or obesity and prediabetes or type 2 diabetes. This is a 12-week, three-arm, parallel-group, single-blind randomised controlled trial including 126 shift workers. Participants are randomised equally to: (A) a high-protein diet with protein-enriched dinner (50–60 % of daily protein); (B) a high-protein diet with protein-restricted dinner (10–20 % of daily protein) or (C) a normoproteic control diet with usual protein distribution. Primary outcomes include changes in glycaemic control and dual-energy X-ray absorptiometry-derived body composition. Secondary outcomes are lipid profile, sleep quality and quality of life. Other clinical and lifestyle parameters are evaluated to monitor changes throughout the intervention. Assessments are performed at baseline, week 6 and week 12. All analyses will follow the intention-to-treat principle. This study will provide new evidence on how evening protein intake may influence metabolic health in populations exposed to circadian disruption.

Background: The Mediterranean Diet (MedDiet) is the dietary pattern par excellence for managing and preventing metabolic diseases, such as Type 2 Diabetes (T2DM). The MedDiet incorporates spices and aromatic herbs, which are abundant sources of bioactive compounds. The aim of this study was to analyze the effect of all aromatic herbs and spices included in the MedDiet, such as black cumin, clove, parsley, saffron, thyme, ginger, black pepper, rosemary, turmeric, basil, oregano, and cinnamon, on the glycemic profile in T2DM subjects. Methods: PubMed, Web of Science, and Scopus databases were searched for interventional studies investigating the effect of these aromatic herbs and spices on the glycemic profile in T2DM subjects. Results: This systematic review retrieved 6958 studies, of which 77 were included in the qualitative synthesis and 45 were included in the meta-analysis. Our results showed that cinnamon, turmeric, ginger, black cumin, and saffron significantly improved the fasting glucose levels in T2DM subjects. The most significant decreases in fasting glucose were achieved after supplementation with black cumin, followed by cinnamon and ginger, which achieved a decrease of between 27 and 17 mg/dL. Conclusions: Only ginger and black cumin reported a significant improvement in glycated hemoglobin, and only cinnamon and ginger showed a significant decrease in insulin.

Objective Adipose tissue stores a substantial amount of body cholesterol in humans. Obesity is associated with decreased concentrations of serum cholesterol. During weight gain, adipose tissue dysfunction might be one of the causes of metabolic syndrome. The aim of this study is to evaluate cholesterol storage and oxidized metabolites in adipose tissue and their relationship with metabolic clinical characteristics. Methods Concentrations of cholesterol and oxysterols (27-hydroxycholesterol and 24S-hydroxycholesterol) in subcutaneous and visceral adipose tissue were determined by high-performance liquid chromatography with tandem mass spectrometry in 19 adult women with body mass index between 23 and 40 kg/m² from the FAT expandability (FATe) study. Tissue concentration values were correlated with biochemical and clinical characteristics using nonparametric statistics. Results Insulin correlated directly with 24S-hydroxycholesterol in both adipose tissues and with 27-hydroxycholesterol in visceral tissue. Leptin correlated directly with 24S-hydroxycholesterol in subcutaneous adipose tissue. Tissue cholesterol correlated directly with 27-hydroxycholesterol in both adipose tissues and with 24S-hydroxycholesterol in visceral tissue, where cholesterol correlation with 24S-hydroxycholesterol was higher than with 27-hydroxycholesterol. In addition, some tendencies were observed: serum high-density lipoprotein cholesterol tended to be inversely correlated with visceral adipose tissue cholesterol; high-sensitivity C-reactive protein tended to be correlated directly with subcutaneous adipose 24S-hydroxycholesterol and inversely with visceral 27-hydroxycholesterol. Conclusions Adipose tissue oxysterols are associated with blood insulin and insulin resistance. Tissue cholesterol correlated more with 27-hydroxycholesterol in subcutaneous adipose tissue and with 24S-hydroxycholesterol in visceral adipose tissue. Levels of adipose 24S-hydroxycholesterol seem to be correlated with some metabolic syndrome symptoms and inflammation while adipose 27-hydroxycholesterol could represent some protection against them.

Background: We investigated the postprandial effects of an alcohol-free beer with modified carbohydrate (CH) composition compared to regular alcohol-free beer. Methods: Two randomized crossover studies were conducted. In the first study, 10 healthy volunteers received 25 g of CH in four different periods, coming from regular alcohol-free beer (RB), alcohol-free beer enriched with isomaltulose and a resistant maltodextrin (IMB), alcohol-free beer enriched with resistant maltodextrin (MB), and a glucose-based beverage. In the second study, 20 healthy volunteers were provided with 50 g of CH from white bread (WB) plus water, or with 14.3 g of CH coming from RB, IMB, MB, and extra WB. Blood was sampled after ingestion every 15 min for 2 h. Glucose, insulin, incretin hormones, TG, and NEFAs were determined in all samples. Results: The increase in glucose, insulin, and incretin hormones after the consumption of IMB and MB was significantly lower than after RB. The consumption of WB with IMB and MB showed significantly less increase in glucose levels than WB with water or WB with RB. Conclusions: The consumption of an alcohol-free beer with modified CH composition led to a better postprandial response compared to a conventional alcohol-free beer.

High plasma level of low-density lipoprotein (LDL) is the main driver of the initiation and progression of cardiovascular disease (CVD). Nevertheless, high-density lipoprotein (HDL) is considered an anti-atherogenic lipoprotein due to its role in reverse cholesterol transport and its ability to receive cholesterol that effluxes from macrophages in the artery wall. The scavenger receptor B class type 1 (SR-B1) was identified as the high-affinity HDL receptor, which facilitates the selective uptake of cholesterol ester (CE) into the liver via HDL and is also implicated in the plasma clearance of LDL, very low-density lipoprotein (VLDL) and lipoprotein(a) (Lp(a)). Thus, SR-B1 is a multifunctional receptor that plays a main role in the metabolism of different lipoproteins. The aim of this review is to highlight the association between SR-B1 and CVD risk through mice and human genetic studies.