Abstract
We are in midst of a global pandemic due to corona virus disease-19 (COVID-19) that has extensively impacted health and well-being. Complementary and alternative medicine (CAM) therapies have been extensively used by the general public in various forms to improve their immunity and stay resilient against the infection. Intermittent fasting (IF) is a popular form of CAM therapy reported to accelerate weight loss, alleviate inflammation, upregulate metabolism and reverse immune system dysfunction. This case report describes the impact of a 9-month long IF protocol (18 h water only phase followed by 6 h of feeding phase) in a 36-year-old male patient who was at high risk of acquiring COVID-19 infection owing to his elevated body mass index, fasting blood sugar, cholesterol, impaired lipid profile, and high level of anxiety. At baseline his antibody status against COVID-19 was 0.01 (OD ratio). Nine months of IF has shown to improve all his clinical parameters. The authors have observed the presence of antibody against COVID-19: 6.35 (OD ratio) during the 9th month follow-up and also 6.94 (OD ratio) during the refeeding phase at 12th month. However the patient exhibited no symptoms or complications during the entire 1 year of the study. The patient also reported considerable reduction in anxiety on the visual analog scale whose score was reduced to 1 compared with the baseline score of 9. The results suggest prolonged IF to be a safe and useful prophylactic measure against COVID-19 and its risk factors. However, large scale studies are warranted to substantiate the present findings.
Introduction
Corona virus disease-19 (COVID-19) has emerged as a serious threat to the health and economical well-being of the general public. As the pandemic progressed, owing to fear of infection, people have adapted various strategies to prevent themselves from COVID-19. Reports suggest the usefulness of various strategies such as phytonutrients and nutritional interventions to improve immunity and help in alleviating COVID-19.1,2 Intermittent fasting (IF) was reported to be highly beneficial in humans due to its immunomodulatory potential. 3
Many reviews suggest IF to be a promising preventive approach against COVID-19 due to its immunomodulatory potential, which is beneficial to the host.4,5 However, clinical studies reporting the direct preventive effect on IF on COVID-19 are scarce. Yoga and naturopathy physicians extensively use fasting as a primary therapeutic tool in prevention and prophylaxis of various diseases. 6 In this study, an interesting observation of a patient who underwent IF for 9 months as a preventive measure against COVID-19 is reported.
Patient Information
A 36-year-old male patient visited the integrative medicine setting with concerns of overweight, dyslipidemia, and with an increased anxiety about getting inflicted with COVID-19 and its complications. He also complained of disturbed sleep, fatigue, and lowered self-esteem.
Clinical Findings
A detailed case history was taken and the height of the patient was found to be 167 cm. His weight was 86 kg and body mass index (BMI) was calculated to be 30.8 kg/m2.
Diagnostic Focus and Assessments
On first consultation, the COVID-19 antibody (enzyme-linked immunosorbent assay [ELISA] test) status of the patient was evaluated that was 0.01 (OD ratio), which signifies no COVID-19 infection in the past. Furthermore, the patient presented with an elevated level of C-reactive protein (6.2 mg/L), fasting blood sugar (102.8 mg/dL), and total cholesterol level (325 g/dL). He had higher state of anxiety that he scored as 9 in a visual analog scale (VAS) that suggests extreme anxiety in baseline. The lipid profile, kidney function test, liver function test, thyroid profile, vitamin B12, vitamin D at base line, and then at an interval of 3 months through 1 year were evaluated to understand the multisystem impact of prolonged IF. The detailed laboratory reports are tabulated in Table 1.
Summary of Clinical Profile from the Baseline Through 12 Months
25-OH, 25-hydroxy; BMI, body mass index; HbA1c, glycated hemoglobin; HDL, high-density lipoprotein; LDL, low-density lipoprotein; OD, optical density; SGOT, serum glutamic-oxaloacetic transaminase; SGPT, serum glutamic pyruvic transaminase; T3, triiodothyronine; T4, thyroxine; TC, total cholesterol; TSH, thyroid stimulating hormone.
Therapeutic Intervention
A prolonged supervised IF program was planned for the patient for 9 months then followed by a refeeding phase. The patient underwent a daily water-only fasting window of 18 h and a feeding period of 6 h (2 pm to 8 pm, Indian Standard Time) where he consumed a normal vegetarian diet that includes cereals, fresh fruits, vegetables, and pulses (two times meal that includes Indian breads, white rice, boiled vegetables, and liquid pulses adding up to 1200 kcal).
During the refeeding phase, the patient was switched back to a normal diet that includes cereals, fresh fruits, vegetables, and pulses (three times meal that includes Indian breads, white rice, boiled vegetables, and liquid pulses adding up to 1500 kcal). Furthermore, the patient was consulted regularly by a licensed yoga and naturopathy physician who evaluated the general well-being of the patient on a daily basis through 1 year.
Follow-Up and Outcomes
Apart from the regular daily follow-up, the changes in clinical/laboratory parameters and anxiety were evaluated at an interval of 3 months from the baseline through 1 year. Total COVID-19 antibody was checked every 3 months by ELISA method to keep a check on his immune status. The patient remained asymptomatic (for COVID-19) throughout the 9 months of IF period and through the 3 months follow-up period wherein he returned back to normal feeding phase.
However, an elevated COVID-19 antibody-total was observed during the 9th month follow-up that remained elevated during the 12th month follow-up as well signifying development of natural immunity against COVID-19. Furthermore, he also had shown clinically significant improvement in inflammation levels, blood glucose levels, lipid profile, vitamin B12, BMI, etc. during the IF period, barring a consistent reduction in vitamin D levels. The detailed clinical profiling of the patient is tabulated in Table 1.
Discussion
Literature suggests the role of nutritional imbalance, stress, inflammation, irrational lifestyle changes etc to induce a dysregulation of immune system that predisposes to many viral diseases including COVID-19. 7 In addition, reviews suggest the role of gut microbiota dysbiosis, comorbidities, etc. as challenges in effective mitigation of COVID-19 pandemic. 8 Earlier studies reported IF to impact oxidative stress, inflammation, metabolism, body weight, and body composition that has a direct impact on immunity.9,10 Further periodic fasting and refeeding are also reported to reduce cardiometabolic risk by inducing gut microbial symbiosis. 11
Reviews focused on prevention and mitigation of COVID-19 recommend IF as one of the key tools that can offer protection against infection.4,12 In addition, altering the metabolic pathways of host cells is identified as a useful strategy in preventing viral infections, as viruses are highly dependent on the host metabolism for their survival.12,13
Preclinical studies on IF implicate IF to revive the hostile metabolic milieu by improved oscillations of the circadian clock gene expression that further resets the pathways linked to energy metabolism. 14 The findings also support the metabolic reprogramming induced by IF, as the authors have noticed significant changes in BMI and other clinical parameters linked to metabolism such as lipid profile and blood glucose. These changes in circadian profile induced by IF are thought to impact the gut permeability that may shift from “obese microbiota” to “lean microbiota.”
This can prevent bacterial translocation that promotes systemic inflammation.15,16 Along with reduction in BMI, this study has shown gradual and significant reduction in C-reactive protein that is suggestive of a change in the gut microbiome. However, this fact needs to be confirmed by future experimental studies.
Fasting is noticed to upregulate autophagy response that is dimmed during nutrient-rich conditions. 17 This capacity of fasting is thought to enhance the resistance of cells against various stressors by priming the metabolic buffering capacity of human cells. 4 Besides the immunometabolic effects, IF is also known to enhance the mood and emotional well-being of individuals. 18 Enhanced psychological well-being is highly warranted considering the negative consequences of COVID-19 over mental health. The tranquility offered by fasting is attributed to the release of endogenous endorphins, increase in the brain-derived neurotrophic factor secretion, and subsequent regulation of serotonins.19,20
Earlier reviews discussing the beneficial role of IF on immune system have suggested IF to mediate immune response through priming the immunologic memory. 21 IF reinforces the function of CD8+ memory T cells that protects against reinfection from bacteria 22 and is also reported to efflorescence cytokine production by T cells in viral reinfections. 23 This report also acknowledges the immunolomodulatory effect of IF. The observations from this case report are supportive of recommending IF as a preventive strategy against COVID-19, as the patient did not report any symptom related to COVID-19 nor reported any adverse event related to fasting during the entire period of fasting as well as subsequent follow-up.
Presence of sufficient amount of antibodies against COVID-19 by the 9th month demonstrates the protective effect of IF over COVID-19. In addition, the observation suggests that IF helps in maintaining the homeostasis of the metabolic functions and reduces anxiety. This can be substantiated from the clinically meaningful changes in blood sugar, cholesterol, BMI, VAS for anxiety, etc. The results of this report are identical to earlier meta-analysis on IF that suggests fasting to enhance glycemic control and reduce BMI. 24
This report suggests that IF can be an effective strategy in overweight/obese individuals during a pandemic, as vaccines are found to be less effective in obese individuals compared with normal weight individuals. 25 Therefore, a healthy weight reduction as reported in this patient will help in boosting metabolic health and immunity. To the authors' knowledge, this is the first report to present the complete clinical profile during long-term IF and to recommend IF to be a probable prophylactic tool against COVID-19.
The results strengthen the hypothesis of promoting IF as a priming tool to elicit host defense against severe acute respiratory syndrome-corona virus-2 infection. 4 As the spread of COVID-19 is still not completely addressed, proactively adapting healthy measures looks like a promising way ahead. Being a single case report, the authors cannot generalize the results observed. Hence, the authors recommend prospective randomized controlled clinical trials to validate the results that can help in increasing the confidence on utilizing IF in prevention and treatment of COVID-19 and its complications.
Patient Perspective
The patient expressed his enthusiasm and satisfaction about the outcome and has reported that IF benefits both physically and mentally.
Informed Consent
The patient signed and informed consent before participating in the fasting program.
Footnotes
Author Disclosure Statement
No competing financial interests exist.
Funding Information
No funding was received for this article.