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Fasting Ramadan During the COVID-19 Pandemic

Dear Editor

Fasting Ramadan During the COVID-19 Pandemic

Ramadan is a holy month for Muslims. The vast majority of healthy adult Muslims practice fasting by abstaining from any food, drinks, and medications from dawn until sunset for 30 days. This year, approximately1.9 billion will observe the month of Ramadan during an unprecedented time; the pandemic of Coronavirus Disease 2019 (COVID-19) which has beena major global threat [1]. Herein, we discuss some of the implications of fasting amid the COVID-19 pandemic.

Currently, there is no evidence suggesting that fasting increases thevulnerability for COVID-19 infection [1], but some studies previously evaluated the effect of fasting on other viral infections. In one animalmodel, anorexia associated with acute influenza illness induced by blocking glucose utilization had a lethal effect [2]. Although intermittent fasting could lead to an early increase in body stress by transient alteration in circadian rhythm and cause a significant diurnalvariation in serum cortisol level which normalises after fasting cessation [3]. One study of 608 healthy non-fasting volunteers showed that a high level of basal salivary cortisol increased the susceptibility to rhinovirus infection and prolonged the viral shedding duration. However, this did not translate into subsequent clinical illness [4]. Supporting this notion, a systematic review of 25 observational studies on healthy individuals found that fasting had no or only mild transient alteration in immune system response [5]. Collectively, these findings suggest that intermittent fasting might increase viral shedding among other non-coronaviruses, but overall the increase in serum cortisol levels due to fasting does not seem to translate to worsening clinical manifestations among the studied viral infections. Whether these findings are applicable to COVID-19 infection is yet to be determined.

Intermittent fasting triggers metabolic switching from glucose based to ketone based energy, which promotes cellular stress resistance, hemopoiteic stem cells self-renewal, and reverses immunosuppression. As aresult, several makers of systemic inflammation and oxidative stress decrease [6]. In a small sized cross-over randomised trial of pre-diabetic men who underwent intermittent fasting for 18 hours a day for 5 weeks, there was a significant improvement in oxidative stress levels without a significant effect on cortisol level or increase risk of infectious events [7]. Middle-Eastern countries with high representation of Muslims have a high prevalence of cardiovascular disease and cardiovascular risk factors [8], which have been linked to worse clinical outcomes among patients with COVID-19 infections [9]. Intermittent fasting promotes cardio-metabolic profile by improving blood pressure, body weight, lipid profile, glucose tolerance, and insulin resistance. These cardio-protective mechanisms are more evident within 2 to 4 weeks of fasting [3,5,6]. Whether these observed cardiometabolic improvements at cellular and metabolic levels are protective against serious adverse events with COVID-19 infection remains an interesting knowledge gap.

Fasting Ramadan has a great spiritual significance for Muslims. As such, we urge Muslim communities to ensure safe Ramadan practices such as maintaining social distancing, healthy hygiene and self-being, with potential cancellation of all social, communal meals, and religious gatherings [1]. Also we suggest modified or extended quarantine protocols up to 21 days for those who have asymptomatic or mildly symptomatic COVID-19 given the theoretical risk of prolonged viral shedding associated with fasting which has been observed with other viral infections, until further evidence becomes available [10]. Although, there have been no studies on fasting and risk of COVID-19 infection; healthy individuals can safely fast. However, high-risk individuals should consult their physicians prior to fasting for their candidacy for fasting and reconciliation of their chronic medical conditions.

1. Safe Ramadan practices in the context of the COVID-19. Interim guidance. (accessed April 23 2020).
2. Wang A, Huen SC, Luan HH, et al. Opposing effects of fasting metabolism on tissue tolerance in bacterial and viral inflammation. Cell2016;166:1512-25.
3. Roky R, Houti I, Moussamih S, et al. Physiological and chronobiological changes during Ramadan intermittent fasting. Ann Nutr Metab 2004;48:296-303.
4. Janicki-Deverts D, Cohen S, Turner RB, et al. Basal salivary cortisolsecretion and susceptibility to upper respiratory infection. Brain Behav Immun 2016;53:255-61.
5. Adawi M, Watad A, Brown S, et al. Ramadan fasting exerts immunomodulatory effects: Insights from a systematic review. Front Immunol 2017;8:1144.
6. de Cabo R, Mattson MP. Effects of intermittent fasting on health, aging, and disease. N Engl J Med 2019;381:2541-51.
7. Sutton EF, Beyl R, Early KS, et al. Early time-restricted feeding improves insulin sensitivity, blood Pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metab 2018;27:1212-21.
8. Roth GA, Johnson C, Abajobir A, et al, et al. Global, regional, and national burden of cardiovascular diseases for 10 causes, 1990 to 2015. JAm Coll Cardiol 2017;70:1-25.
9. hou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020;395:1054-62.
10. To KK, Tsang OT, Leung WS, et al. Temporal profiles of viral load inposterior oropharyngeal saliva samples and serum antibody responses during infection by SARS-CoV-2: an observational cohort study. Lancet Infect Dis 2020. pii: S1473-3099(20)30196-1.

Competing interests: No competing interests

28 April 2020
Akram Y. Elgendy
Cardiovacular Medicine Fellow; MD, MRCP
Islam Y. Elgendy, MD, FESC, FAHA, FACC, FACP; Massachusetts General Hospital, Boston
University of Florida
1600 SW Archer RD, Division of Cardiovascular Medicine, Gainesville, Florida