Nutrition plays a critical role in immunity by providing essential energy, amino acids, minerals, and vitamins necessary for immune cells to function effectively, especially in the elderly.
Poor or unhealthy diets can lead to malnutrition and chronic inflammation, weakening the immune system and increasing vulnerability to infections like COVID-19.
Maintaining gut health through a balanced diet rich in fiber, prebiotics, and probiotics is crucial, as viruses like SARS-CoV-2 can infect intestinal cells and disrupt the gut microbiome, leading to gastrointestinal symptoms and complications.
Diets focusing on vegetables, fruits, whole grains, and healthy fats—such as the whole-food plant-based diet and the Mediterranean diet—enhance immune function by supplying essential nutrients and reducing inflammation.
Additionally, adopting healthy lifestyle interventions—including regular physical activity, adequate sleep, stress management, avoidance of harmful substances, social connectedness, and positive psychology—further supports immune health and overall well-being.
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Lifestyle categories |
Recommendations |
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Nutrition |
Fiber‐rich, nutrient‐dense, antioxidant‐rich whole food plant foods such as green leafy vegetables (3‐5 servings/day), fruits (2‐4 servings/day), whole grains, legumes, nuts and seeds Moderate intake of foods with unsaturated fats (like fish, avocado, nuts, olive oil, soy/canola/sunflower/corn oils), white/lean meat and low‐fat dairy products Limit salt consumption, soft drinks, or sodas Avoid foods/snacks containing saturated fats (fatty/red meats, butter, palm/coconut oils, cream, cheese, ghee, lard), trans fats and processed carbohydrates Maintain a healthy weight keeping BMI 18.5‐24.9 kg m−2 Aim for optimal hydration: drink 2‐3 L water a day |
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Physical activity |
Engage in moderate‐intensity aerobic physical activity (e.g., brisk walk/dance) 30 min‐1 h/day or 150‐300 min per week, plus resistance exercise (e.g., press‐ups, sit-ups, and weights) for 1 h, two to three times/week on nonconsecutive days Exercise caution with patients in moderate stage of COVID‐19 who may be breathless on exertion |
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Sleep |
Improving sleep hygiene, aiming for 7‐8 h uninterrupted, restorative sleep every night |
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Harmful substances |
Avoid any form of tobacco products, or any other harmful substances Drink modestly (ensuring alcohol free days) or no alcohol Smoking, vaping, or inhaling any substance can damage the lungs. Make the most of available support for quitting |
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Stress management |
Adopt a variety of measures to keep stress levels low, including favorite music, videos, and movies Talking to a trusted person can help when feeling afraid or sad, avoiding such feelings becoming overwhelming Use reliable sources, such as the World Health Organisation. Minimize anxiety by limiting news, current affairs, and stressful drama. Keep a positive attitude, accepting we cannot control events Consider relaxation techniques such as deep breathing, meditation, Yoga, Tai Chi, and mindfulness, using apps or online resources |
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Social connectedness |
Stay socially connected with loved ones, family and friends by phone, zoom, WhatsApp, and social media if government advice prevents physical meetings Avoid social isolation |
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Positive psychology |
Do activities and direct your thoughts to enhance well‐being and create positive emotions, such as counting blessings, kindness practices, focusing on personal goals/strengths Always find joy, meaning, and purpose, focusing on what makes life worth living Think about the things that call for gratitude and bring happiness Keep your reflections happy and be optimistic about recovery |
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Intervention/strategy |
Risk reduction
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Infection |
Severe disease |
Mortality |
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Vegan/vegetarian diet |
73% |
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High diet quality, largely plant-based |
10% |
40% |
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High fruit, vegetable & nut consumption (OR for low) |
86% (OR 12.22) |
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Normal BMI |
63% (OR 2.73) |
74% (OR 3.81) |
38% (OR 1.61) |
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51.9% (OR 2.08)a |
29.6% (OR 1.42) |
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Active/regular exercise |
15% (aRR 0.85) |
58% (aRR 0.42) |
76% (aRR 0.24) |
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55.8% (OR 2.26) |
59.8% (OR 2.49) |
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Sufficient sleep (compared to insufficient sleep) |
88.4% (OR 8.61) |
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One extra hour of sleep |
12% (OR 0.88) |
17% (OR 0.83) |
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Vitamin D supplements |
88% (OR 0.12)d |
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9%–24%e |
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Sufficient vitamin D |
43.5% (OR 1.77) |
61.1% (OR 2.57) |
77.1% (OR 4.36)f |
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45.1% |
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Curcumin (turmeric) |
80%g and 50%g |
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Increased gut health |
33% |
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Multivitamins |
12%–22%d |
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Omega-3 fatty acid supplements |
12%–21%d |
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aRR; adjusted relative risk; BMI: body mass index; OR: odds ratio. (a) hospitalisation in Western countries; (b) severe disease in Asian populations; (c) over 60 years old; (d) taken after coronavirus disease 2019 diagnosis; (e) depending on country; (f) mean of two models; (g) as nano-curcumin; (h) as standard curcumin with piperine.
Source: Campbell, Jessica L. “COVID-19: Reducing the risk via diet and lifestyle.” Journal of integrative medicine vol. 21,1 (2023): 1-16. doi:10.1016/j.joim.2022.10.001 Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories,
Monye, Ifeoma, and Abiodun Bamidele Adelowo. “Strengthening immunity through healthy lifestyle practices: Recommendations for lifestyle interventions in the management of COVID-19.” Lifestyle medicine (Hoboken, N.J.) vol. 1,1 (2020): e7. doi:10.1002/lim2.7 This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/