Effects of Daytime Dry Fasting on Hydration, Glucose Metabolism and Circadian Phase: A Prospective Exploratory Cohort Study in Bahá'í Volunteers

Background: Religiously motivated Bahá'í fasting (BF) is a form of intermittent dry fasting celebrated by abstaining from food and drinks during daylight hours every year in March for 19 consecutive days.

Aim: To test the safety and effects of BF on hydration, metabolism, and the circadian clock.

Methods: Thirty-four healthy Bahá'í volunteers (15 women) participated in this prospective, exploratory cohort study. Laboratory examinations were carried out in four study visits: before fasting (V0), in the third week of fasting (V1) as well as 3 weeks (V3) and 3 months (V4) after fasting. Data collection included blood and urine samples, anthropometric measurements and bioelectrical impedance analysis. At V0 and V1, 24- and 12-hour urine and serum osmolality were measured. At V0–V2, alterations in the circadian clock phase were monitored in 16 participants. Our study was augmented by an additional survey with 144 healthy Bahá'í volunteers filling out questionnaires and with subgroups attending metabolic measurements (n = 11) and qualitative interviews (n = 13), the results of which will be published separately.

Results: Exploratory data analysis revealed that serum osmolality (n = 34, p < 0.001) and 24-hour urine osmolality (n = 34, p = 0.003) decreased during daytime fasting but remained largely within the physiological range and returned to pre-fasting levels during night hours. BMI (body mass index), total body fat mass, and resting metabolic rate decreased during fasting (n = 34, p < 0.001), while body cell mass and body water appeared unchanged. The circadian phase estimated by transcript biomarkers of blood monocytes advanced by 1.1 h (n = 16, p < 0.005) during fasting and returned to pre-fasting values 3 weeks after fasting. Most observed changes were not detectable anymore 3 months after fasting.

Conclusions: Results indicate that BF (Bahá'í fasting) is safe, has no negative effects on hydration, can improve fat metabolism and can cause transient phase shifts of circadian rhythms.

Trial Registration:https://www.clinicaltrials.gov/, identifier: NCT03443739.

Prolonged multimodal fasting modulates periodontal inflammation in female patients with metabolic syndrome: A prospective cohort study

AIM

To determine the potential anti-inflammatory effect of a multimodal periodic fasting programme on surrogate parameters of periodontal inflammation in hospitalized patients diagnosed for metabolic syndrome (MetS).

MATERIAL AND METHODS

A total of 47 patients were recruited and hospitalized in an integrative ward for an intensified two-week multimodal fasting, diet and lifestyle programme. Patients were periodontally examined at baseline (t1), after the 2-week fasting protocol (t2) and, subsequently, 4 months after fasting (t3). The following parameters were determined: periodontal screening index (PSI), bleeding on probing (BOP), gingival crevicular fluid volume (GCF), plaque index (PI), C-reactive protein (CRP), blood pressure (BP), waist circumference (WC), fasting glucose (FGLU), triglycerides (TRG), high-density lipoprotein (HDL) and HbA1c.

RESULTS

A total of 28 female and 8 male patients fulfilled the defined criteria for MetS and were analysed separately by gender. At t2, BOP and GCF were reduced when compared to t1 (median: t2 = 39; t1 = 33.1%; p < .001 and t2 = 73.9; t1 = 59.3 Periotron units p = .02, respectively). BOP reduction correlated to FGLU (R = .37, p = .049) and weight reduction (R = .4, p = .04).

CONCLUSION

This study showed for the first time that clinically supervised periodic fasting in female patients with MetS may facilitate the reduction of periodontal inflammation.

Dry Fasting Physiology: Responses to Hypovolemia and Hypertonicity

OBJECTIVE

The aim of this study was to provide a deeper insight into dry fasting (DF) physiology.

DESIGN

Ten participants performed DF for 5 consecutive days.

METHODS

The following parameters were monitored daily: cortisol, aldosterone, high-sensitivity C-reactive protein (CRP), erythropoietin, albumin, uric acid, and vitamin C in serum; vasopressin (ADH), adrenocorticotropic hormone (ACTH), renin, angiotensin II, and total antioxidant capacity (TAC) in plasma; hematocrit and erythrocytes in whole blood; osmolality, noradrenaline, dopamine, adrenaline, Na+, and K+ in 24-h urine; waist circumference and body, urine, and stool weight.

RESULTS

The following parameters increased: ADH (60 ± 11%), ACTH (176 ± 34%), cortisol (495 ± 75%), urine osmolality (20 ± 4%), CRP (167 ± 77%), renin (315 ± 63%), angiotensin II (74 ± 21%), aldosterone (61 ± 21%), TAC (80.4 ± 17%), uric acid (103 ± 19%), albumin (18.4 ± 2.4%), erythrocytes (13.4 ± 2.2%), hematocrit (11 ± 1.8%), and the excretion of noradrenaline (40.3 ± 10%) and dopamine (17 ± 5%). The following parameters decreased: waist circumference (8.20 ± 0.61 cm), body weight (7.010 ± 0.3 kg), erythropoietin (65 ± 18%), and the excretion of adrenaline (38 ± 4%) and Na+ (60 ± 16%). The excretion of K+ remained unchanged. Vitamin C decreased, showing a half-life of 4.8 ± 0.7 days. The percent ratios of lost weight components were: urine (52.2 ± 3.7%), insensible water loss (32.2 ± 1.4%), stool (5 ± 0.3%), and respiratory gases, i.e., expired CO2 - incorporated O2 (10.6 ± 5.4%).

CONCLUSION

The mechanisms underlying the hypertonicity and hypovolemia compensation and the ratio analysis of lost weight components were presented. DF demonstrated short-term antioxidant, anti-ischemic, immune-stimulating, anti-edematous, and anti-inflammatory effects. The results may have an impact on developing new concepts for the treatment of edema, obesity, and inflammatory and ischemic diseases.

From Religion to Secularism: the Benefits of Fasting

PURPOSE OF REVIEW

Since the early development of human societies, religious beliefs, and practices has been integral to their identity, culture, and social structure, traditions are influenced by the area, era, and culture wherein they developed. Some religions offer advice on behavioral and diet modifications as strategies to fortify the body, purify the spirit, and elevate consciousness. This review is an attempt to compare different practices, describe the health benefits and risks of fasting, and reconcile these age-old recommendations with practical modern life.

RECENT FINDINGS

Research to clarify and quantify the impact of these dietary modifications is challenging due to the variability in recommendations among various religions and in day-to-day practices. Most religions share common goals of well-being, body-mind integration, and spiritual attainment. Historically, the transformational power of fasting periods has been appreciated, but there is still much to discover about the underlying beneficial physiologic mechanisms of fasting in preventing and treating metabolic diseases.