Diet for COVID-19: real-time analysis of all 23 studies

Diet for COVID-19: real-time meta analysis of 15 studies

Covid Analysis (Preprint) (meta analysis)

• Statistically significant improvement is seen for cases. 12 studies from 12 independent teams in 7 different countries show statistically significant improvements in isolation (11 for the most serious outcome).

• Meta analysis using the most serious outcome reported shows 53% [39‑64%] improvement. Results are similar after exclusions.

• Results are robust — in exclusion sensitivity analysis 13 of 15 studies must be excluded to avoid finding statistically significant efficacy in pooled analysis.

• Studies analyze diet quality before infection, and use different definitions of diet quality.

• No treatment, vaccine, or intervention is 100% available and effective for all variants. All practical, effective, and safe means should be used. Denying the efficacy of treatments increases mortality, morbidity, collateral damage, and endemic risk.

• All data to reproduce this paper and sources are in the appendix.

Covid Analysis et al., 8/12/2022, preprint, 1 author.

Long-term diet and risk of SARS -CoV-2 infection and Coronavirus Disease 2019 (COVID-19) severity

Yue et al., The American Journal of Clinical Nutrition, doi:10.1093/ajcn/nqac219

Analysis of 42,935 participants showing lower risk of COVID-19 with healthier diets. Risk of severe cases was also lower with healthier diets, while not reaching statistical significance. Severity results are only provided with diet indices as a continuous variable.

risk of case, 19.0% lower, OR 0.81, p = 0.008, Q4 vs. Q1, model 3 + IPW, AHEI, RR approximated with OR.

risk of case, 21.0% lower, OR 0.79, p = 0.006, Q4 vs. Q1, model 3 + IPW, AMED, RR approximated with OR.

risk of case, 28.6% lower, OR 0.71, p < 0.001, Q1 vs. Q4, model 3 + IPW, EDIH, RR approximated with OR.

risk of case, 11.5% lower, OR 0.88, p = 0.10, Q1 vs. Q4, model 3 + IPW, EDIP, RR approximated with OR.

Yue et al., 8/9/2022, retrospective, multiple countries, peer-reviewed, survey, 11 authors.

Higher Adherence to the Mediterranean Dietary Pattern Is Inversely Associated With Severity of COVID-19 and Related Symptoms: A Cross-Sectional Study

Zargarzadeh et al., Frontiers in Medicine, doi:10.3389/fmed.2022.911273

Retrospective 250 COVID-19 patients in Iran, showing lower risk of severe disease with greater adherence to a Mediterranean diet.

risk of severe case, 77.0% lower, OR 0.23, p < 0.001, higher quality diet 89, lower quality diet 80, adjusted, top tertile vs. lowest tertile, MD score, model 3, multivariable, RR approximated with OR.

Zargarzadeh et al., 7/19/2022, retrospective, Iran, peer-reviewed, mean age 44.1, 11 authors, study period June 2021 - September 2021.

Suboptimal Consumption of Relevant Immune System Micronutrients Is Associated with a Worse Impact of COVID-19 in Spanish Populations

Galmés et al., Nutrients, doi:10.3390/nu14112254

Ecological study in Spain, showing diets lower in vitamin D, A, B9, and zinc in regions with the highest COVID-19 incidence and mortality.

Vitamin D intake was associated with lower prevalence, incidence, and a combined incidence+mortality index. Vitamin A intake was correlated with lower incidence, ∆incidence, and combined incidence+mortality, while not reaching statistical significance (p = 0.09, 0.07, 0.06). Vitamin B9, B12, and zinc were associated with lower ∆incidence.

Authors analyze 10 vitamins and minerals endorsed by the European Food Safety Authority (EFSA) as having sufficient evidence for a causal relationship between intake and optimal immune system function: vitamins D, A, C, B6, B9, B12, zinc, copper, iron, and selenium.

The intake of all 10 showed an inverse correlation with ∆incidence and combined incidence+mortality (statistically significant only as shown).

Galmés et al., 5/27/2022, Spain, peer-reviewed, 3 authors.

Nutritional Risk Assessment Scores Effectively Predict Mortality in Critically Ill Patients with Severe COVID-19

Bodolea et al., Nutrients, doi:10.3390/nu14102105

Retrospective 90 severe COVID-19 ARDS patients in Romania, showing nutritional risk assessment scores PNI, CONUT, NUTRIC, and mNUTRIC to be independent predictors of mortality.

Bodolea et al., 5/18/2022, retrospective, Romania, peer-reviewed, survey, median age 67.0, 8 authors, study period December 2020 - March 2021.

Cardiovascular risk factor insights into the Tesco 1.0 Dataset

Pimenta et al., European Journal of Preventive Cardiology, doi:10.1093/eurjpc/zwac056.304

Tesco grocery purchase retrospective, showing COVID-19 mortality correlated with myocardial infarction mortality risk factors. Salt, percentage of fat and oils, and total weight increased risk, while fiber was protective.

Pimenta et al., 5/11/2022, United Kingdom, peer-reviewed, 2 authors.

The Role of Nutrition in COVID-19: Taking a Lesson from the 1918 H1N1 Pandemic

Kahleova et al., American Journal of Lifestyle Medicine, doi:10.1177/15598276221097621 (Review)

Review of evidence suggesting that a healthy diet reduces risk for COVID-19.

Kahleova et al., 5/2/2022, peer-reviewed, 2 authors.

COVID-19 Illness Severity in the Elderly in Relation to Vegetarian and Non-vegetarian Diets: A Single-Center Experience

Hou et al., Frontiers in Nutrition, doi:10.3389/fnut.2022.837458

Retrospective 509 COVID-19 patients in Taiwan, showing higher risk of critical COVID-19 cases with non-vegetarian diets.

risk of critical case, 71.6% lower, RR 0.28, p = 0.23, higher quality diet 1 of 22 (4.5%), lower quality diet 78 of 487 (16.0%), NNT 8.7, excluded in exclusion analyses: unadjusted results with no group details.

risk of moderate to critical case, 10.8% lower, RR 0.89, p = 0.66, higher quality diet 11 of 22 (50.0%), lower quality diet 273 of 487 (56.1%), NNT 17, excluded in exclusion analyses: unadjusted results with no group details.

risk of critical case, 73.6% lower, RR 0.26, p = 0.005, higher quality diet 0 of 9 (0.0%), lower quality diet 47 of 127 (37.0%), NNT 2.7, adjusted, OR converted to RR, multivariable, age >65.

risk of moderate to critical case, 34.7% lower, RR 0.65, p = 0.04, higher quality diet 5 of 9 (55.6%), lower quality diet 108 of 127 (85.0%), NNT 3.4, age >65, excluded in exclusion analyses: unadjusted results with no group details.

Hou et al., 4/29/2022, retrospective, Taiwan, peer-reviewed, survey, 3 authors, study period May 2021 - August 2021.

The Association between Energy-Adjusted Dietary Inflammatory Index, Body Composition, and Anthropometric Indices in COVID-19-Infected Patients: A Case-Control Study in Shiraz, Iran

Firoozi et al., International Journal of Clinical Practice, doi:10.1155/2022/5452488

Retrospective 133 COVID-19 patients and 322 controls, showing higher risk of COVID-19 for diets that have a higher inflammatory index (E-DII).

risk of case, 65.0% lower, OR 0.35, p < 0.001, adjusted, case control OR, multivariable, per unit E-DII change.

Firoozi et al., 3/29/2022, retrospective, Iran, peer-reviewed, survey, 8 authors, study period March 2020 - June 2020.

Components of the Mediterranean Diet and Risk of COVID-19

Perez-Araluce et al., Frontiers in Nutrition, doi:10.3389/fnut.2021.805533

Retrospective 5,194 participants in Spain with 382 COVID-19 cases, showing lower risk of COVID-19 with high adherence to a Mediterranean diet, with statistical significance only when excluding healthcare professionals.

risk of severe case, 77.9% lower, RR 0.22, p = 0.15, higher quality diet 1 of 1,103 (0.1%), lower quality diet 10 of 3,300 (0.3%), NNT 471, OR converted to RR, high vs. low adherence.

risk of symptomatic case, 15.1% lower, RR 0.85, p = 0.31, higher quality diet 52 of 1,103 (4.7%), lower quality diet 214 of 3,300 (6.5%), OR converted to RR, high vs. low adherence.

risk of case, 19.7% lower, RR 0.80, p = 0.14, higher quality diet 58 of 1,103 (5.3%), lower quality diet 248 of 3,300 (7.5%), OR converted to RR, high vs. low adherence.

Perez-Araluce et al., 1/24/2022, retrospective, Spain, peer-reviewed, survey, 4 authors, study period March 2020 - December 2020.

Associations of Nutritional Behavior and Gut Microbiota with the Risk of COVID-19 in Healthy Young Adults in Poland

Jagielski et al., Nutrients, doi:10.3390/nu14020350

Retrospective 95 people in Poland, showing significantly lower risk of COVID-19 with higher consumption of fruits, vegetables, and nuts. Diets with higher consumption of fruits, vegetables, and nuts had a significantly lower dietary inflammatory index.

risk of case, 81.5% lower, RR 0.18, p = 0.005, higher quality diet 4 of 40 (10.0%), lower quality diet 9 of 20 (45.0%), NNT 2.9, adjusted, OR converted to RR, model 2, FV ≥ 500g and nuts ≥ 10g vs. FV < 500g and nuts < 10g, multivariable.

Jagielski et al., 1/14/2022, retrospective, Poland, peer-reviewed, 7 authors.

Flight attendant occupational nutrition and lifestyle factors associated with COVID-19 incidence

Yamamoto et al., Scientific Reports, doi:10.1038/s41598-021-04350-0

Retrospective 84 flight attendants, 52 reporting COVID-19 status and diet quality, showing higher risk of COVID-19 with lower self-reported diet quality.

risk of case, 66.3% lower, RR 0.34, p = 0.009, higher quality diet 4 of 20 (20.0%), lower quality diet 19 of 32 (59.4%), NNT 2.5, good, very good, excellent vs. fair, poor.

Excluded in after exclusion results of meta analysis: unadjusted results with no group details.

Yamamoto et al., 12/30/2021, retrospective, USA, peer-reviewed, survey, mean age 35.0, 3 authors.

Influence of mediterranean diet on survival from covid-19 disease

Magaña et al., Clinical Nutrition ESPEN, doi:10.1016/j.clnesp.2021.09.606

Retrospective 89 COVID-19 patients in Spain, showing lower mortality with adherence to the Mediterranean diet.

risk of death, 53.0% lower, HR 0.47, p = 0.049, higher quality diet 58, lower quality diet 31.

Excluded in after exclusion results of meta analysis: unadjusted results with no group details.

Magaña et al., 12/31/2021, retrospective, Spain, peer-reviewed, 6 authors.

Single and Combinative Impacts of Healthy Eating Behavior and Physical Activity on COVID-19-like Symptoms among Outpatients: A Multi-Hospital and Health Center Survey

Nguyen et al., Nutrients, doi:10.3390/nu13093258

Analysis of 3,947 participants in Vietnam, showing significantly lower risk of COVID-19-like symptoms with physical activity and with a healthy diet. The combination of being physically active and eating healthy reduced risk further compared to either alone. The analyzed period was Feb 14 to Mar 2, 2020, which may have been before testing was widely available.

risk of symptomatic case, 15.2% lower, RR 0.85, p = 0.006, higher quality diet 345 of 1,054 (32.7%), lower quality diet 433 of 1,082 (40.0%), NNT 14, adjusted, OR converted to RR, high vs. low HES, COVID-19-like symptoms, multivariable.

risk of symptomatic case, 42.0% lower, OR 0.58, p < 0.001, adjusted, high HES and physically active, COVID-19-like symptoms, multivariable, RR approximated with OR.

Nguyen et al., 9/18/2021, retrospective, Vietnam, peer-reviewed, survey, 17 authors, study period 14 February, 2020 - 2 March, 2020.

Lifestyle risk factors and infectious disease mortality, including COVID-19, among middle aged and older adults: Evidence from a community-based cohort study in the United Kingdom

Ahmadi et al., Brain, Behavior, and Immunity, doi:10.1016/j.bbi.2021.04.022

Retrospective 468,569 adults in the UK, showing significantly lower COVID-19 mortality with physical activity.

risk of death, 3.0% higher, RR 1.03, p = 0.85, adjusted, good vs. poor, model 2, multivariable.

Ahmadi et al., 8/31/2021, retrospective, United Kingdom, peer-reviewed, 5 authors.

The relationship between Dietary Inflammatory Index and disease severity and inflammatory status: a case–control study of COVID-19 patients

Moludi et al., British Journal of Nutrition, doi:10.1017/S0007114521003214

Retrospective 60 COVID-19 hospitalized patients and 60 controls in Iran, showing pro-inflammatory diets associated with COVID-19 cases and severity. IR.KUMS.REC.1399·444, IR.TBZMED.REC.1399·225.

risk of case, 91.6% lower, OR 0.08, p < 0.001, case control OR, model 3, E-DII tertile 1 vs. tertile 3.

Moludi et al., 8/23/2021, retrospective, Iran, peer-reviewed, 7 authors, study period June 2020 - July 2020.

Inverse Association Between the Mediterranean Diet and COVID-19 Risk in Lebanon: A Case-Control Study

El Khoury et al., Frontiers in Nutrition, doi:10.3389/fnut.2021.707359

Retrospective 399 people in Lebanon, showing a significant inverse association between the MedDiet score, corresponding to the level of adherence to the Mediterranean diet, and the risk of COVID-19.

El Khoury et al., 7/30/2021, retrospective, Lebanon, peer-reviewed, 2 authors.

Nutritional and lifestyle changes required for minimizing the recovery period in home quarantined COVID-19 patients of Punjab, Pakistan

Rabail et al., Food Science & Nutrition, doi:10.1002/fsn3.2458

Survey of 80 recovered COVID-19 patients in Pakistan, showing faster recovery with improved nutrition.

Rabail et al., 7/9/2021, Pakistan, peer-reviewed, survey, 11 authors, study period November 2020 - February 2021.

Diet quality and risk and severity of COVID-19: a prospective cohort study

Merino et al., Gut, doi:10.1136/gutjnl-2021-325353 (preprint 6/25/2021)

Retrospective 592,571 participants in the UK and USA with 31,815 COVID-19 cases, showing lower risk or COVID-19 cases and severity for higher healthful plant-based diet scores. Notably, the assocation was less evident with higher levels of physical activity.

risk of severe case, 41.0% lower, HR 0.59, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted, model 3, high vs. low hPDI, multivariable, Cox proportional hazards.

risk of case, 18.0% lower, HR 0.82, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted, model 3, high vs. low hPDI, PCR+, multivariable, Cox proportional hazards.

risk of case, 9.0% lower, HR 0.91, p < 0.001, higher quality diet 148,142, lower quality diet 148,143, adjusted, model 3, high vs. low hPDI, multivariable, Cox proportional hazards.

Merino et al., 6/25/2021, retrospective, multiple countries, peer-reviewed, survey, 30 authors, study period 24 March, 2020 - 2 December, 2020.

Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case–control study in six countries

Kim et al., BMJ Nutrition, Prevention & Health, doi:10.1136/bmjnph-2021-000272

Retrospective healthcare workers in six countries with exposure to COVID-19 patients, showing lower risk of moderate/severe COVID-19 with plant-based diets.

risk of moderate/severe case, 72.0% lower, OR 0.28, p = 0.02, higher quality diet 41, lower quality diet 527, adjusted, plant-based diets, multivariable, RR approximated with OR.

risk of moderate/severe case, 59.0% lower, OR 0.41, p = 0.05, higher quality diet 46, lower quality diet 522, adjusted, plant-based or pescatarian diets, multivariable, RR approximated with OR.

risk of case, 19.0% lower, OR 0.81, p = 0.24, higher quality diet 41, lower quality diet 527, adjusted, plant-based diets, multivariable, RR approximated with OR.

risk of case, 23.0% lower, OR 0.77, p = 0.14, higher quality diet 46, lower quality diet 522, adjusted, plant-based or pescatarian diets, multivariable, RR approximated with OR.

Kim et al., 6/7/2021, retrospective, multiple countries, peer-reviewed, survey, 8 authors, study period 17 July, 2020 - 25 September, 2020.

Mediterranean Diet and SARS-COV-2 Infection: Is There Any Association? A Proof-of-Concept Study

Ponzo et al., Nutrients, doi:10.3390/nu13051721

Retrospective 1,206 healthcare professionals in Italy, showing the risk of COVID-19 infection inversely associated with adherence to the Mediterranean diet.

Ponzo et al., 5/19/2021, retrospective, Italy, peer-reviewed, survey, 9 authors.

Insights from a Pan India Sero-Epidemiological survey (Phenome-India Cohort) for SARS-CoV2

Naushin et al., eLife, doi:10.7554/eLife.66537

Retrospective 10,427 volunteers in India, 1,058 anti-nucleocapsid antibody positive, showing lower risk of seropositivity with a vegetarian diet.

risk of seropositive, 40.1% lower, OR 0.60, p < 0.001, RR approximated with OR.

Naushin et al., 4/20/2021, retrospective, India, peer-reviewed, survey, 136 authors.

Negative Association Between Mediterranean Diet Adherence and COVID-19 Cases and Related Deaths in Spain and 23 OECD Countries: An Ecological Study

Greene et al., Frontiers in Nutrition, doi:10.3389/fnut.2021.591964

Analysis of 17 regions in Spain, showing an inverse association between adherence to the Mediterranean diet and COVID-19 cases and mortality.

Greene et al., 3/5/2021, peer-reviewed, 3 authors.

Seroprevalence of IgG against SARS-CoV-2 and its determinants among healthcare workers of a COVID-19 dedicated hospital of India

Mahto et al., American Journal of Blood Research, 11:1

Retrospective 689 healthcare workers in India, showing non-statistically significant lower risk of IgG positivity with a vegetarian diet in unadjusted results.

risk of IgG positive, 20.4% lower, RR 0.80, p = 0.32, higher quality diet 23 of 206 (11.2%), lower quality diet 70 of 483 (14.5%), NNT 30, unadjusted, OR converted to RR.

Excluded in after exclusion results of meta analysis: unadjusted results with no group details.

Mahto et al., 2/15/2021, retrospective, India, peer-reviewed, 6 authors.

Current State of Evidence: Influence of Nutritional and Nutrigenetic Factors on Immunity in the COVID-19 Pandemic Framework

Galmés et al., Nutrients, doi:10.3390/nu12092738

Ecological study of European countries analyzing 10 vitamins and minerals endorsed by the European Food Safety Authority as having sufficient evidence for a causal relationship between intake and optimal immune system function: vitamins D, A, C, B6, B9, B12, zinc, copper, iron, and selenium.

Dietary intake levels of all 10 showed an inverse correlation with the relative mortality rate, while all except vitamin B6 and selenium showed an inverse correlation with incidence and mortality. Most individual correlations did not reach statistical significance. Authors note greater association in populations genetically predisposed towards lower micronutrient status.

Galmés et al., 9/8/2020, retrospective, peer-reviewed, 3 authors.

Antiandrogens	(meta)	Melatonin	(meta)
Aspirin	(meta)	Metformin	(meta)
Bamlaniv../e..	(meta)	Molnupiravir	(meta)
Bebtelovimab	(meta)	N-acetylcys..	(meta)
Bromhexine	(meta)	Nigella Sativa	(meta)
Budesonide	(meta)	Nitazoxanide	(meta)
Cannabidiol	(meta)	Nitric Oxide	(meta)
Casirivimab/i..	(meta)	Paxlovid	(meta)
Colchicine	(meta)	Peg.. Lambda	(meta)
Conv. Plasma	(meta)	Povidone-Iod..	(meta)
Curcumin	(meta)	Probiotics	(meta)
Diet	(meta)	Proxalutamide	(meta)
Ensitrelvir	(meta)	Quercetin	(meta)
Ensovibep	(meta)	Remdesivir	(meta)
Exercise	(meta)	Sleep	(meta)
Famotidine	(meta)	Sotrovimab	(meta)
Favipiravir	(meta)	Tixagev../c..	(meta)
Fluvoxamine	(meta)	Vitamin A	(meta)
Hydroxychlor..	(meta)	Vitamin C	(meta)
Iota-carragee..	(meta)	Vitamin D	(meta)
Ivermectin	(meta)	Zinc	(meta)
Lactoferrin	(meta)

Other Treatments		Global Adoption