Different patterns of changes in free 25-hydroxyvitamin D concentrations during intermittent fasting among meat eaters and non-meat eaters and correlations with amino acid intake.

We prospectively assessed changes in free 25-hydroxyvitamin D [25(OH)D] and vitamin D binding protein (VDBP) among overweight adults who followed a pescatarian Orthodox intermittent fasting regimen (n = 59) and controls who followed a low-fat 12:12 diet (n = 46). Total and free 25(OH)D, parathyroid hormone, VDBP, anthropometric data, and amino acid intake were evaluated in both groups at three time points: at baseline, 7 weeks after diet implementation, and 5 weeks after participants returned to their usual eating habits (12 weeks from baseline). An increase in amino acid intake between baseline and 12 weeks was independently correlated with higher free 25(OH)D values at 12 weeks for both groups. Our findings suggest that diet can affect free 25(OH)D concentrations, through variations in amino acid intake, independently of exposure to sunlight, providing novel mechanistic insights into the future planning of vitamin D supplementation strategies. However, this hypothesis needs to be tested in larger studies.

Implementation of Christian Orthodox fasting improves plasma adiponectin concentrations compared with time-restricted eating in overweight premenopausal women.

The exact mechanisms mediating the metabolic effects of Orthodox fasting remain unclear. Plasma adiponectin, biochemical and anthropometrical data were evaluated in 55 Orthodox fasters (OF) and 42 time-restricted eating controls (all women, mean age 47.8 years) at three time points: baseline, end of the dietary intervention (7 weeks) and 5 weeks after participants returned to their typical dietary habits (12 weeks from baseline). In the OF group, there was an increase in adiponectin values at 12 weeks compared with baseline (9815.99 vs 8983.52 mg/ml, p = 0.02) and a reduction in body fat mass between baseline and 12 weeks (35.44 vs 32.17%, p = 0.004) and between 7 and 12 weeks (35.33 vs 32.17%, p = 0.003). In the same group, an inverse correlation between adiponectin and waist circumference values was observed over the entire study period. Our results provide novel evidence that Orthodox fasting has favourable metabolic effects related to improved adiponectin concentrations.

Similar late effects of a 7-week orthodox religious fasting and a time restricted eating pattern on anthropometric and metabolic profiles of overweight adults.

A hypocaloric diet, based on Orthodox fasting (OF) was followed by 29 overweight adults. A low-calorie, 16/8, time restricted eating (TRE) pattern was followed by 16 age- and weight-matched participants. Anthropometric, lipid, glycaemic and inflammation markers were assessed at baseline, at the end of the intervention (7 weeks from baseline) and 6 weeks after the cessation of diets (13 weeks from baseline). There was a trend of weight loss in both groups, which was evident at week 7 (TRE: -2.1 ± 1.0; OF: -2.0 ± 0.5 kg, p < 0.001 from baseline) and remained significant at week 13 (TRE: -2.9 ± 0.7; OF: -2.6 ± 0.3 kg, p < 0.001 from baseline). In the OF group, lipid concentrations declined at week 7 compared with baseline, increasing at week 13 compared with week 7. Our findings suggest that OF promotes a decrease in lipid concentrations, which however, is not evident 6 weeks after its end.

Effects of orthodox religious fasting versus combined energy and time restricted eating on body weight, lipid concentrations and glycaemic profile.

For seven weeks, 37 overweight adults followed a hypocaloric diet based on Orthodox Fasting (OF). A hypocaloric, time restricted eating (TRE) plan (eating between 08:00 to 16:00 h, water fasting from 16:00 to 08:00 h) was followed by 23 Body Mass Index (BMI)-matched participants. Anthropometric, glycaemic and inflammation markers and serum lipids were assessed before and after the diets. Both OF and TRE groups demonstrated reductions in BMI (28.54 ± 5.45 vs 27.20 ± 5.10 kg/m2, p < 0.001 and 26.40 ± 4.11 vs 25.81 ± 3.78 kg/m2 p = 0.001, respectively). Following the intervention, the OF group presented lower concentrations of total and low-density lipoprotein-cholesterol, compared with the pre-fasting values (178.40 ± 34.14 vs 197.17 ± 34.30 mg/dl, p < 0.001 and 105.89 ± 28.08 vs 122.37 ± 29.70 mg/dl, p < 0.001, respectively). Neither group manifested significant differences in glycaemic and inflammatory parameters. Our findings suggest that OF has superior lipid lowering effects than the TRE pattern.

A Mediterranean Eating Pattern Combining Energy and Time-Restricted Eating Improves Vaspin and Omentin Concentrations Compared to Intermittent Fasting in Overweight Individuals.

Athonian Orthodox fasting (AOF) is characterized by energy- and time-restricted eating (TRE) and is based on the Mediterranean diet. We aimed to investigate the impact of AOF compared to another TRE model on vaspin, omentin, nesfatin, and visfatin levels. We included 25 individuals (mean age 50.3 ± 8.6 years, 24% men) who practiced AOF and abstained from animal products, with the exception of seafood and fish. This group adopted a 12 h eating interval (08.00 to 20.00). In total, 12 participants (mean age 47.7 ± 8.7 years, 33.3% men) who practiced 16:8 TRE (eating from 09:00 to 17:00) and were allowed to consume meat served as the controls. Anthropometric and dietary data and adipokine levels were prospectively collected at three time points: at baseline, after the end of the diets (7 weeks), and 5 weeks after the participants returned to their typical eating habits (12 weeks from baseline). Vaspin levels decreased [795.8 (422.1-1299.4) (baseline) vs. 402.7 (203.8-818.9) (7 weeks) pg/mL, p = 0.002] and omentin levels increased [568.5 (437.7-1196.5) (baseline) vs. 659.0 (555.7-1810.8) (12 weeks) pg/mL, p = 0.001] in the AOF group, while none of the analyzed adipokines changed significantly in the TRE group. The variations observed in vaspin and omentin concentrations in the AOF group were independent of age, sex, changes in anthropometry and fat intake. In conclusion, AOF can significantly reduce vaspin and increase omentin, whose levels are known to increase and decrease, respectively, in obesity and type 2 diabetes. The implications of these findings for cardiometabolic health warrant further investigation.

Effects of Christian Orthodox Fasting Versus Time-Restricted Eating on Plasma Irisin Concentrations Among Overweight Metabolically Healthy Individuals.

Irisin has been recently identified as an adipomyokine produced during physical activity and involved in the browning of adipose tissue. Despite the emerging evidence suggesting an inverse relationship between irisin plasma concentrations and adverse metabolic outcomes, the exact impact of diet on irisin levels remains obscure. Thus, we aimed to assess the effects of two dietary patterns, Christian Orthodox fasting (OF) and 16:8 time-restricted eating (TRE), on circulating irisin levels among overweight, metabolically healthy, adults. Plasma irisin, glucose and lipid parameters, calcium homeostasis, and anthropometry were evaluated in 29 Orthodox fasters and 14 age and body mass index (BMI)-matched TRE controls (mean age and BMI, 48.8 years and 28.7 kg/m2, respectively) at three, distinct time points-before the implementation of the energy-restricted diets (baseline), at the end of the dietary intervention (7 weeks) and 5 weeks after participants returned to their typical dietary habits (12 weeks from baseline). Repeated measures analysis was applied to assess differences between the two groups and the effect of several indices on irisin levels at all three time points. At 12 weeks, the OF group manifested higher irisin concentrations compared with both its baseline values (64.3 ± 54.4 vs. 43.6 ± 42.2 ng/mL, p = 0.01) and those of the TRE group at the same time point (64.3 ± 54.4 vs. 44.2 ± 26.6 ng/mL, p = 0.04). Glycemic, lipid, and anthropometric parameters were not found to correlate with irisin levels. In contrast, parathyroid hormone (PTH) concentrations at 12 weeks correlated with irisin concentrations (p = 0.04), indicating that lower values of irisin are expected for higher PTH measurements. The findings of this pilot study suggest favorable long-term effects of OF on irisin levels. The interplay between irisin, PTH, and diet warrants further investigation.

Vitamin D equilibrium affects sex-specific changes in lipid concentrations during Christian Orthodox fasting.

We aimed to evaluate sex differences in changes of lipid profiles in a cohort of metabolically healthy adults following Orthodox fasting (OF), as well as to assess a potential role of vitamin D status in mediating these variations. 45 individuals (24 premenopausal females, 53.3 %) with mean age 48.3 ± 9.1 years and mean Body Mass Index 28.7 ± 5.8 kg/m2 were prospectively followed for 12 weeks. Anthropometry, dietary and biochemical data regarding serum lipids, and vitamin D status were collected at baseline, 7 weeks after the implementation of OF, and 5 weeks after fasters returned to their standard dietary habits (12 weeks from baseline). According to 25-hydroxy-vitamin D [25(OH)D] measurements, participants were divided into two groups: those with concentrations above and below the median of values. Females with 25(OH)D concentrations below the median manifested a non-significant reduction by approximately 15 % in total and low-density lipoprotein cholesterol during the fasting period, followed by a significant increase 5 weeks after OF cessation (170.7 vs. 197.5 and 99.6 vs. 121.0 mg/dl respectively, p < 0.001). In contrast, males with 25(OH)D levels below the median demonstrated an inverse, non-significant trend of increase in lipid concentrations during the whole study period. Our findings suggest strikingly different inter-gender lipid responses to a dietary model of low-fat, mediated by vitamin D status. Further studies are necessary to reveal the underlying mechanisms and assess the importance of these differences with respect to cardiovascular health and the benefit of vitamin D supplementation strategies.

Isoprostane as a marker of oxidative stress in chronic heroin users: correlation with duration of heroin use or concomitant hepatitis C infection.

BACKGROUND: Although chronic heroin abuse has been extensively linked to oxidative stress, and while plasma 15-F(2t)-IsoP is considered a good indicator of oxidative stress, there remain few references in the literature about the plasma concentration of this marker in heroin dependent subjects. OBJECTIVES: To determine plasma 15-F(2t)-IsoP, as a marker of oxidative stress, in chronic heroin users, and to examine whether the values of this marker correlate with the duration of heroin use or with the presence of anti-HCV antibodies. METHODS: Forty-two chronic heroin users and twenty two healthy control subjects were recruited for this study. An enzyme-immunoassay method was used for the determination of 15-F(2t)-IsoP in plasma. RESULTS: Plasma 15-F(2t)-IsoP values were significantly higher in chronic heroin users compared to healthy controls. No correlation was found between the values of plasma 15-F(2t)-IsoP and the duration of heroin use. Heroin dependent subjects positive for anti-HCV antibodies had significantly lower values of plasma 15-F(2t)-IsoP as compared to those without a history of HCV infection. CONCLUSIONS: The elevated plasma 15-F(2t)-IsoP values in heroin dependent subjects, compared to healthy individuals, indicate a shift of the balance between oxidants and antioxidants towards the former and suggest that heroin dependent subjects could benefit from an antioxidant therapy.