The lifestyle adopted by most people in Western societies has an important impact on the propensity to metabolic disorders (e.g., diabetes, cancer, cardiovascular disease, neurodegenerative diseases). This is often accompanied by chronic low-grade inflammation, driven by the activation of various molecular pathways such as STAT3 (signal transducer and activator of transcription 3), IKK (IκB kinase), MMP9 (matrix metallopeptidase 9), MAPK (mitogen-activated protein kinases), COX2 (cyclooxigenase 2), and NF-Kβ (nuclear factor kappa-light-chain-enhancer of activated B cells). Multiple intervention studies have demonstrated that lifestyle changes can lead to reduced inflammation and improved health. This can be linked to the concept of real-life risk simulation, since humans are continuously exposed to dietary factors in small doses and complex combinations (e.g., polyphenols, fibers, polyunsaturated fatty acids, etc.). Inflammation biomarkers improve in patients who consume a certain amount of fiber per day; some even losing weight. Fasting in combination with calorie restriction modulates molecular mechanisms such as m-TOR, FOXO, NRF2, AMPK, and sirtuins, ultimately leads to significantly reduced inflammatory marker levels, as well as improved metabolic markers. Moving toward healthier dietary habits at the individual level and in publicly-funded institutions, such as schools or hospitals, could help improving public health, reducing healthcare costs and improving community resilience to epidemics (such as COVID-19), which predominantly affects individuals with metabolic diseases.

In this research, a model for the estimation of antioxidant content in cherry fruits from multispectral imagery acquired from drones was developed, based on machine learning methods. For two consecutive cultivation years, the trees were sampled on different dates and then analysed for their fruits’ radical scavenging activity (DPPH) and Folin–Ciocalteu (FCR) reducing capacity. Multispectral images from unmanned aerial vehicles were acquired on the same dates with fruit sampling. Soil samples were collected throughout the study fields at the end of the season. Topographic, hydrographic and weather data also were included in modelling. First-year data were used for model-fitting, whereas second-year data for testing. Spatial autocorrelation tests indicated unbiased sampling and, moreover, allowed restriction of modelling input parameters to a smaller group. The optimum model employs 24 input variables resulting in a 6.74 root mean square error. Provided that soil profiles and other ancillary data are known in advance of the cultivation season, capturing drone images in critical growth phases, together with contemporary weather data, can support site- and time-specific harvesting. It could also support site-specific treatments (precision farming) for improving fruit quality in the long-term, with analogous marketing perspectives.

Background: There is a growing consensus that fasting-induced ketosis has beneficial effects on human physiology. Despite these compelling benefits, fasting-induced ketosis raises concerns in some clinicians because it is often inappropriately compared with the pathologic uncontrolled ketone production in diabetic ketoacidosis. The determinants of the inter-individual differences in the intensity of ketosis during long-term fasting is unknown. Methods: We monitored daily variations in fasting ketonemia, as well as ketonuria, which is less invasive, in a large cohort of 1610 subjects, fasting between 4 and 21 days with the Buchinger Wilhelmi program, minimally supplemented with ~75–250 kcal (daily fruit juice, vegetable soup, and honey). Results: Ketonuria was detected in more than 95% of fasting subjects from day 4 onwards. Subjects consuming only soups, without fruit juice or honey, exhibited reduced caloric intake (72 kcal instead of 236 kcal) and carbohydrate intake (15.6 g instead of 56.5 g), leading to more intense ketonuria. Participants with high ketonuria were, in the majority, males, young, had a higher body weight, and had lower HDL-C and urea values. They had a larger decrease in blood glucose, glycated haemoglobin levels, body weight, and waist circumference. Furthermore, in the high-ketonuria group, a larger increase in blood uric acid concentration was observed. Conclusion: Our study showed that long-term fasting triggered ketosis, never reaching pathological levels, and that ketosis is influenced by age, gender, health, and the level of physical activity. Furthermore, it is modulated but not suppressed by minimal carbohydrate intake. Our study paves the way for better understanding how supplementation can modulate the therapeutic effects and tolerability of long-term fasting.

Background/Objectives: The Mediterranean diet has been widely suggested to exert significant beneficial effects on endothelial oxidative status and cardiometabolic health. Greek Orthodox monasteries, due to their specific nutritional and sartorial habits, comprise a population thatstrictly adheres to nutritional patterns with restricted eating and a plant-based subset of the Mediterranean diet, often accompanied by profound hypovitaminosis D. Time-restricted eating (TRE) is also adopted bya large part of the general lay Greek population for health-promoting reasons, without restrictions on animal product consumption, as imposed by Orthodox religious fasting. However, the comparative effects of these nutritional patterns on oxidative stress markers remain scarce. Methods: The present study attempted to evaluate the effects of Christian Orthodox fasting (COF) in a group of vitamin D-deficient and overweight Orthodox nuns from Central and Northern Greece compared to the implementation of TRE, a 16:8 dietary regimen (16 h of food abstinence and 8 h of feeding) in a cohort of adult women from the general population from the same region with regard to markers of endothelial oxidative status. A group of 50 women from two Orthodox monasteries in Northern Greece and one group of 50 healthy lay women were included. During the enrollment, a detailed recording of their dietary habits was performed, along with a scientific registry of their demographic and anthropometric characteristics (via bioimpedance). The Orthodox nuns followed a typical Orthodox fasting regimen [daily feeding window (8 a.m.–4 p.m.)], whereas the lay women followed a TRE 16:8 regimen with the same feeding time-window with a recommendation to follow a low-fat diet, without characteristics of the Mediterranean diet. We included a complete biochemical analysis, as well as calciotropic profiles [calcium—Ca, albumin, parathyroid hormone—PTH, and 25-hydroxyvitamin D—25(OH)D] and markers of TAC (total antioxidant capacity), GSH (glutathione),and thiobarbituric acid reactive substances (TBARSs) concentrations as markers of oxidative status. Results: All the groups were compared at the baseline regarding their calcium, PTH, and 25(OH)D concentrations, with no statistically significant differences between the groups apart from higher PTH levels in the nuns due to lower 25(OH)D levels. The Orthodox nuns manifested a lower median GSH compared to the controls (6.0 vs. 7.2, p 0.04) and a higher median TAC (0.92 vs. 0.77, p < 0.001). The TBARS comparisons showed no significant difference between the two groups. No significant associations of oxidative status with 25(OH)D, PTH, and the markers of glucose homeostasis were evident. Conclusions: The results of this small pilot study indicate that both dietary regimens have advantages over the oxidative markers compared to each other, with increased TAC in the group of Orthodox nuns after a 16-week period of COF compared to a 16:8 TRE and increased GSH concentrations in the lay women group. Future randomized trials are required to investigate the superiority or non-inferiority between these dietary patterns in the daily clinical setting.

Mediterranean diet has been widely suggested to exert significant beneficial effects on endothelial oxida-tive status and cardiometabolic health. Greek Orthodox monasteries, due to their specific nutritionaland sartorial habits, comprise a population which strictly adheres to nutritional patterns with restricted eating and a plant-based subset of the Mediter-ranean diet, often accompanied by profound hypovitaminosis D. Time –restricted eating is also adopted from a large part of general lay Greek population for health promoting reasons, without restrictions on an-imal product consumption, as imposed by Orthodox religious fasting. However, comparative effects of these nutritional patterns on oxidative stress markers remain scarce. The present study attempted to evaluate the effects of Christian Orthodox fasting (COF) in a group of vitamin D –deficient and overweight Orthodox nuns from Central and Northern Greece, compared to the implementation of TRE, 16:8 dietary regimen in a cohort of adult women from the general population from the same region, with regard to markers of endothelial oxidative status. A group of 50 women from two Orthodox monasteries in Northern Greece and one group of 50 healthy lay women were included. During enrollment a detailed recording of dietary habits was performed, along with a scientific registry of demographic and anthropometric characteristics (via bioimped-ance).Orthodox nuns followed a typical Orthodox fasting regimen[daily feeding window (8 am–4 pm)] whereas lay women followed a TRE 16:8 regimen with the same feeding time-window with recommenda-tion to follow a low-fat diet, without characteristics of the Mediterranean diet. We included a complete biochemical analysis, as well as calciotropic profiles [Calcium-Ca, Albumin, Parathyroid hormone-PTH, 25-hydroxyvitamin D- 25(OH)D] as well as and markers of TAC (trichloroacetic acid), (glutathione) GSH and thiobarbituric acid reactive substances (TBARS) concentrations, as markers of oxidative status. All groups were comparable at baseline for calcium, PTH and 25(OH)D concentrations, with no significant differences between groups. Orthodox nuns manifested a lower median GSH compared to con-trols (6.0 vs. 7.2, p 0.04) and a higher median TAC (0.92 vs. 0.77, p <0.001). TBARS comparisons showed no significant difference between the two groups. No significant associations of oxidative status with 25(OH)D, PTH and markers of glucose homeostasis were evident. Results of this small pilot study indicate that both dietary regimens have advantages over oxidative markers compared to each other, with increased TAC in the groups of Orthodox Nuns after a 16th week period of COF compared to a 16:8 TRE and increased GSH concentrations in the lay women group. Future randomized trials are required to investigate superiority or non-inferiority between these dietary patterns, in the daily clinical setting.

Background: Vitamin D supplementation may influence oxidative stress, but evidence in populations following specific dietary patterns is limited. Methods: In this non-randomized, two-group exploratory study, 50 Orthodox nuns received vitamin D supplementation (2000 IU/day orally) for 16 weeks, whereas 50 age-matched women following time-restricted eating (TRE) served as controls receiving no supplementation. Anthropometric parameters, serum 25-hydroxyvitamin D [25(OH)D], and oxidative stress markers—total antioxidant capacity (TAC), glutathione (GSH), and thiobarbituric acid reactive substances—were measured at baseline and post-intervention. Results: At baseline, both groups were comparable in anthropometric and oxidative stress markers, except for serum 25-hydroxyvitamin D [25(OH)D], which was lower in the intervention group. Following supplementation, serum 25(OH)D increased from 15.77 ± 5.21 to 31.24 ± 7.87 ng/mL (p = 0.031) in Orthodox nuns. No significant changes were observed for TAC (0.93 ± 0.11 to 0.97 ± 0.09, p = 0.081) and GSH (6.01 ± 1.55 to 5.81 ± 1.41, p = 0.069), whereas TBARS decreased significantly (7.32 ± 1.31 to 6.94 ± 1.21, p = 0.041). No significant changes were observed in controls under TRE. Changes (Δ) in all variables represented the post–pre difference over the 16-week period. Pearson correlations showed no significant associations between Δ25(OH)D and ΔTAC (r = −0.244, p = 0.346), ΔGSH (r = 0.110, p = 0.675), or ΔTBARS (r = −0.116, p = 0.657). In multivariable regression adjusted for age, weight, body fat percentage, and baseline 25(OH)D, Δ25(OH)D was not an independent predictor of oxidative stress marker changes; however, weight (β = 0.08, p = 0.011) and body fat percentage (β = −0.13, p = 0.014) were associated with reductions in TBARS. Conclusions: In conclusion, sixteen weeks of vitamin D supplementation in women adhering to Orthodox fasting produced no consistent improvements in oxidative stress markers. While a small reduction in TBARS was observed, this effect was modest and appeared indirect, being more closely associated with decreases in body weight and fat mass than with vitamin D status itself. Taken together, our findings indicate an overall neutral impact of vitamin D on redox balance, suggesting that any antioxidant benefit is likely secondary to metabolic or adiposity-related changes.