Effects of the COVID-19 pandemic reinforced intuitive relationships between suffering from infirmity and mental/physical health. Of course, the emergence of the novel coronavirus has taken a negative toll on population health and well-being. However, the inverse of that relationship is not as intuitive but may also be true. We expect healthy people to get less sick, but do they have any specific protection against coronavirus? Do wellness, wellness habits, and psychological well-being have any impact on the rate and severity of infection from the virus? It may be surprising to learn these questions are being empirically studied. An enormous repository of published pandemic-related research is growing rapidly, and many COVID studies address issues surrounding wellness (i.e., status and habits). Wellness habits, particularly related to exercise and diet, are well-studied. This blog focuses on these questions while describing findings from related research. The accompanying Reading List contains the relevant citations, and most all are freely available open access via a Google search.
Wellness Habits: Exercise and COVID
While well studied, there is only one randomized controlled trial of the effects of exercise on COVID. Researchers asked 30 COVID patients with mild or moderate symptoms to exercise while recuperating in Turkish hospitals. They assigned half of the patients to 40 minutes of moderate-intensity aerobic exercise (treadmill or bike) and half to a control group. After just two weeks, they concluded the exercise group improved COVID-related symptomology and immune profile (leukocytes, lymphocytes, IgA) better than non-exercising patients. It is encouraging to see exercise being investigated as a treatment, and, this behavioral change has a positive impact on patients’ progression at such a critical time in their convalescence.
Another study of COVID patients (n=145) examined the effects of prior habitual physical activity on COVID symptoms (fever, cough, sore throat, loss of taste, etc). Physical activity was self-reported using a questionnaire asking about the type and duration of regular weekly activities. This study found participation in prior moderate physical activity was the only independent predictor of COVID symptomology with greater habitual activity lessening the number of symptoms experienced during COVID. This suggests an active lifestyle might lessen suffering after COVID infection.
Another impressive and much larger study, also done retrospectively, examined prior exercise habits in nearly 50,000 COVID patients tracked by Kaiser-Permanente electronic health records. Inactive patients (those who consistently did not exercise over the prior two years) had more than twice the likelihood of hospitalization from COVID infection than those who were previously meeting physical activity guidelines (>150 min of physical activity weekly). They were also more than twice as likely to die from complications of the infection. Patients who previously engaged in some physical activity were better off than those who did no activity, but these light exercisers had poorer outcomes than those who met published activity guidelines. The Kaiser-Permanente study is a landmark paper showing an active lifestyle can improve outcomes during a pandemic.
These effects of exercise habits on COVID-19 are not completely unexpected because similar results have been seen in American studies with other types of upper respiratory tract infection. A decrease in the rate and severity of infection is commonly seen in those who regularly perform moderate-intensity exercise. There are sound immunologic reasons to expect a beneficial exercise effect on COVID-19. These immune system mechanisms are nicely addressed by Codella et al. (see Reading List) and include effects on immunoglobulins (e.g., IL-6), T-cells, and natural killer cells. Regular exercise also initiates mechanisms to reduce chronic inflammation, and this can be potentially beneficial to COVID patients who may suffer from fluid accumulation in the lungs.
Wellness Habits: Nutrition and COVID
Like exercise, nutrition can also play a role in immune system function and resistance to infection. Glutathione, vitamins A, D, and C are all known immune influencers. As described in a recent review (see Scudiero et al. in Reading List), each of these nutrients was studied in COVID patients. All were shown to have a potential beneficial impact on the course of recovery when kept in proper balance. The merits of Vitamin D effects on COVID progression have been argued in the popular press; the limited data we have suggests it may be helpful, especially in cases of Vitamin D deficiency. The immune system connections to good nutrition have been further elucidated by others (see Calder et al. in Reading List).
On a macro-dietary level, adherence to the Mediterranean diet was shown to lessen COVID infection rate and related mortality. As opposed to the traditional Western diet, the Mediterranean diet is rich in fresh fruit and vegetables, whole grain, nuts, fish, and olive oil. While very encouraging to see a drop in COVID cases associated with this diet, the study did not go so far as to clearly describe the extent of reduction in infection rate. The authors discussed the limitations of their ecological study design but ultimately concluded that any diet-reducing inflammation might reduce the risk for severe COVID. A similar argument of benefit has been postulated for the Keto diet (see Gangitano in Reading List). However, this proposal currently has a smaller evidence base and is more speculative than the case made for the beneficial effects of the Mediterranean diet on COVID.
Another study, using data from the World Health Organization, globally evaluated 23 dietary attributes across 188 countries. They found diet can greatly impact COVID recovery and death rates and emphasized the negative role of sugar consumption in this effect. The authors simply stated, “Good nutrition is important before, during, and after an infection.” They concluded unbalanced diets are a health threat across the world and urged policymakers to make societal modifications for healthier dietary choice accessibility.
A Harvard study presented large-scale evidence for nutrition-based COVID protection. Examining over 500,000 participants, in a cell-phone based project, they reported a high-quality diet (plant-based: fruits and veggies) was associated with a lower risk of COVID infection and lower risk of disease severity. In other words, a diet much like the aforementioned Mediterranean diet provides a protective effect against COVID. It was valuable to learn this dietary effect was prominent in persons living in disadvantaged conditions. In summary, diet like exercise, can impact the COVID pandemic experience.
Wellness Status and COVID
Wellness status (e.g., BMI, stress level, fitness) appears to have a strong relationship with COVID-19 infection and infection outcomes. Obesity is possibly the most studied characteristic, and it is clear that obesity leads to a greater rate of infection and a poorer prognosis once infected. A meta-analysis using 41 studies and over 200,000 subjects (more than 100,000 infected) concluded obese subjects have more positive COVID test findings and greater incidence of hospitalization, intensive care, ventilator use, and mortality. Specifically, visceral fat is the culprit and researchers have speculated it may be responsible for the “cytokine storm” reported in severely deteriorating COVID cases. One theoretical paper postulated this potentially fatal and exaggerated immunological response is related to chronic psychological stress (see Lamontange et al. in Reading List). These authors speculated patients with a history of chronic stress ought to seek strategies of stress reduction that can be implemented during a period of social isolation.
Other wellness-related indicators that predict COVID outcomes are fitness, age, and disease status. Those with greater cardiorespiratory fitness had a lower rate of dying after COVID infection than a less fit cohort. Moreover, performance on maximal exercise testing was shown to be inversely related to the likelihood of COVID hospitalization. The message is clear, increasing fitness level through habitual exercise leads to protective effects during a pandemic!
Male gender, older age, diabetes, and chronic illness are risk factors each associated with poorer COVID outcomes. A study of over 3,700 COVID patients in New York determined male gender and having more than two comorbidities (e.g., heart failure, dementia) increased odds for hospitalization and death. A meta-analysis reiterated the negative impact of male gender and diabetes and added hypertension, smoking history, and fatigue to the list of risk factors for severe COVID. Those with these risk factors should be especially careful and should seek the most effective rehabilitative measures should they become infected with COVID. It seems clear that wellness status is a critical factor in COVID prognosis and poor initial health greatly worsens outcomes expected after a COVID diagnosis.
We can conclude that healthy behavioral habits, such as regular exercise and a plant-based diet, appear to be protective against becoming infected or suffering greatly if infected by the coronavirus. Being physically fit, maintaining normal body composition, and avoiding unhealthy stress are also important to maintaining health during a pandemic. Health care professionals, especially health and wellness coaches, can take this information and use it to help those trying to safely make it through these difficult times. From a broader perspective, healthy behavior habits can now be encouraged to attenuate the effects of future COVID variants or unforeseen pandemics that might be down the road. Add this benefit to the ever-growing list of advantages attributed to living a healthy lifestyle.
Wellness Habits: Exercise and COVID
Mohamed AA, Alawna M. The effect of aerobic exercise on immune biomarkers and symptoms severity and progression in patients with COVID-19: A randomized control trial. J Bodyw Mov Ther. 2021;28:425-432. doi:10.1016/j.jbmt.2021.07.012
Zeigler Z, Lawrence J, Jamison A, Salzano P. Physical Activity Behaviors and COVID-19 Symptoms. OBM Integrative and Complementary Medicine 2021; 6(3): 11; doi: 10.21926/obm.icm.2103027.
Sallis R, Young DR, Tartof SY, et al. Physical inactivity is associated with a higher risk for severe COVID-19 outcomes: a study in 48 440 adult patients. British Journal of Sports Medicine 2021;55:1099-1105. https://bjsm.bmj.com/content/55/19/1099
Codella R, Chirico A, Lucidi F, Ferrulli A, La Torre A, Luzi L. The immune-modulatory effects of exercise should be favorably harnessed against COVID-19. J Endocrinol Invest. 2021;44(5):1119-1122. doi:10.1007/s40618-020-01403-5
Wellness Habits: Nutrition and COVID
Scudiero O, Lombardo B, Brancaccio et al. . Exercise, Immune System, Nutrition, Respiratory and Cardiovascular Diseases during COVID-19: A Complex Combination. Int J Environ Res Public Health. 2021 Jan 21;18(3):904. doi: 10.3390/ijerph18030904. PMID: 33494244; PMCID: PMC7908487.
DeLuccia R, Clegg D, Sukumar D. The implications of vitamin D deficiency on COVID-19 for at-risk populations. Nutr Rev. 2021 Jan 9;79(2):227-234. doi: 10.1093/nutrit/nuaa092. PMID: 32974671; PMCID: PMC7543577. (Calder Nutrim).
Greene MW, Roberts AP, Frugé AD. Negative Association Between Mediterranean Diet Adherence and COVID-19 Cases and Related Deaths in Spain and 23 OECD Countries: An Ecological Study. Front Nutr. 2021 Mar 5;8:591964. doi: 10.3389/fnut.2021.591964. PMID: 33748170; PMCID: PMC7973012.
Gangitano E, Tozzi R, Gandini O, et al. Ketogenic Diet as a Preventive and Supportive Care for COVID-19 Patients. Nutrients. 2021 Mar 20;13(3):1004. doi: 10.3390/nu13031004. PMID: 33804603; PMCID: PMC8003632.
Kamyari N, Soltanian AR, Mahjub H, Moghimbeigi A. Diet, Nutrition, Obesity, and Their Implications for COVID-19 Mortality: Development of a Marginalized Two-Part Model for Semicontinuous Data. JMIR Public Health Surveill. 2021 Jan 26;7(1):e22717. doi: 10.2196/22717. PMID: 33439850; PMCID: PMC7842860.
Merino J, Joshi AD, Nguyen LH, et al. Diet quality and risk and severity of COVID-19: a prospective cohort study. Gut. 2021 Nov;70(11):2096-2104. doi: 10.1136/gutjnl-2021-325353. Epub 2021 Sep 6. PMID: 34489306; PMCID: PMC8500931.
Wellness Status and COVID
Yang J, Hu J, Zhu C. Obesity aggravates COVID-19: A systematic review and meta-analysis. J Med Virol. 2021 Jan;93(1):257-261. doi: 10.1002/jmv.26237. Epub 2020 Oct 5. PMID: 32603481; PMCID: PMC7361606.
Sattar N, McInnes IB, McMurray JJV. Obesity Is a Risk Factor for Severe COVID-19 Infection: Multiple Potential Mechanisms. Circulation. 2020 Jul 7;142(1):4-6. doi: 10.1161/CIRCULATIONAHA.120.047659. Epub 2020 Apr 22. PMID: 32320270.
Favre G, Legueult K, Pradier C et al. Visceral fat is associated to the severity of COVID-19. Metabolism. 2021 Feb;115:154440. doi: 10.1016/j.metabol.2020.154440. Epub 2020 Nov 25. PMID: 33246009; PMCID: PMC7685947.
Lamontagne, S. J., Pizzagalli, D. A., & Olmstead, M. C. (2021). Does inflammation link stress to poor COVID-19 outcome? Stress and Health, 37( 3), 401– 414. https://doi.org/10.1002/smi.3017
Rahman A, Sathi NJ. Risk factors of the severity of COVID-19: A meta-analysis. Int J Clin Pract. 2021 Jul;75(7):e13916. doi: 10.1111/ijcp.13916. Epub 2020 Dec 20. PMID: 33372407.