COVID 19/Coronavirus & Diet
COVID 19/Coronavirus & Diet
The global pandemic resulting from COVID-19/Coronavirus has created a great deal of angst and uncertainty as people around the world look for ways to protect themselves and their loved ones from contracting and spreading the virus. And while evidence-based practices like social-distancing and hand washing have been adopted, many other unfounded approaches continue to circulate online. The following is a collection of evidence-based nutrition practices that may contribute to enhanced immunity. However, it’s important to note that no diet or supplement has effectively prevented/treated COVID-19/Coronavirus; only hand washing, disinfecting frequently touched services, and social distancing can reduce your chances of contracting the virus.
Can what I eat improve my immune system?
Absolutely. Several nutrients (discussed below) play a role in the normal functioning of the immune system. Furthermore, diet is central in the prevention of many chronic health conditions that may undermine our body’s ability to respond to acute illness, including cardiovascular disease, diabetes, and renal disease. In addition, it is known that excess weight can impair immune function, increase the risk of infection, and result in poor outcomes among infected individuals. As such, engaging in lifestyle practices that improve your overall health and well-being can strengthen your immune system.
What should I eat to achieve good health during COVID-19/Coronavirus?
A more detailed discussion on food safety can be found below but it’s important to highlight that no cases of COVID-19/Coronavirus have been linked to food. Remember, COVID-19/Coronavirus is a respiratory virus, not a digestive one.
If you want to increase your body’s antioxidant capacity (which can fight inflammation/oxidative damage), then an unprocessed, plant-based diet is the way to go. On average, plant foods have 64 times more antioxidants than meat, fish, eggs, and dairy, so include plenty of fresh or frozen fruits and vegetables, dried or canned pulses,raw nuts and seeds, and unprocessed whole grains (such as quinoa, brown rice, amaranth, bulgur, sweet potato, wheat berries, etc.) in your diet.
Also, be mindful when it comes to alcohol since excess consumption is linked to an increase in inflammation. During the pandemic, it’s important to access healthy coping mechanisms such as meditation, colouring, or exercise, to help deal with heightened feelings of anxiety and stress.
Greger M. Antioxidant content of 3139 foods. NutritionFacts.org. 2011 Aug;5. Available from: https://nutritionfacts.org/video/antioxidant-content-of-3139-foods/.
What nutrients are important for immunity?
Several vitamins and minerals have integral roles in maintaining a healthy immune system. A few of the key players and their sources include:
Vitamin A (beta carotene) – orange fruits and vegetables, cooked spinach
Vitamin B6 – chickpeas, salmon, chicken/turkey, banana
Vitamin B12 – animal-based foods, supplements
Vitamin C – red/green pepper, orange, grapefruit, kiwi, broccoli, Brussel sprouts, strawberries, cantaloupe
Vitamin D – few dietary sources provide adequate vitamin D; obtain through supplements
Vitamin E – wheat germ oil, sunflower seeds, almonds, sunflower/safflower oil, peanut butter
Zinc – oysters, animal protein, baked beans, pumpkin seeds, cashews, hemp seeds, wheat germ
Folate – cooked spinach, black-eyed peas, asparagus, Brussel sprouts, lettuce, avocado, broccoli
Magnesium – nuts, seeds, whole grains, leafy green vegetables
Selenium – the best source is Brazil nuts. Limit to max 4 per day
In general, healthy people are advised to meet the recommended intake for each of these nutrients through diet (you can use Cronometer to track your intake of each of these nutrients), rather than supplements. However, the International Society for Immunonutrition (ISIN) recommends that the elderly achieve much higher levels of certain nutrients due to the decline in immunity that accompanies the aging process.
Recommendations from the ISIN are as follows:
Vitamin E (134 mg - 800 mg/day)
Zinc (30 mg - 220 mg/day)
Vitamin C (200 mg - 2 g/day)
Vitamin D (2000IU - 4000 IU/day)
If you are not elderly, and struggle to meet the recommended intakes of immune-boosting nutrients, you may wish to supplement with the following (higher doses should be discussed with your physician first):
Vitamin D: 2000-4000 IU per day
Vitamin C: 500 -2000 mg per day
Zinc: 40 mg/day
Magnesium: 200 mg/day
Again, it’s important to emphasize that research on COVID-19/Coronovirus is just emerging and few, if any, studies have been rigorously peer-reviewed. The following information is based on previously published literature form unrelated trials:
Routine supplementation of 50 mg to 2000 mg may reduce the incidence of pneumonia and duration/severity of the common cold.
Zinc acetate taken at a dose > 75 mg after the onset of a cold may reduce its duration.
North American ginseng (200 mg 2x per day for 4 months) will not prevent acute respiratory infections but may shorten their duration.
Some evidence exists to suggest that probiotics can reduce the incidence and duration of respiratory tract infections, but there is lack of evidence to recommend a particular strain, dose, or route of administration.
Increase foods that can have an anti-inflammatory effect like Ginger, Garlic, Raw Honey, Turmeric, and Cinnamon.
Are there any food safety concerns I should be aware of?
For a detailed review on food safety and the COVID-19/Coronavirus, check out J. Kenji López-Alt’s fantastic article.
As mentioned, there is no data to suggest that COVID-19/Coronavirus spreads through food. However, practicing food safety is still important for preventing foodborne illness and mitigating the transfer of the virus. It may be advisable to shop at smaller grocery stores, outside of peak hours, in order to limit contact with others. Be careful not to touch your face while shopping and upon arriving home, transfer foods to clean containers and/or sanitize the package. If you’re at all worried of the presence of COVID-19/Coronavirus in your food, remember that heating food (outside layer) to 149°F (65°C) for at least 3 minutes can destroy the virus. And most importantly, don’t forget to wash your hands before, during, and after cooking and handling food!
Sample Immune-Boosting Diet
Oats (1/4 cup)
Oat bran (1/4 cup)
Unsweetened plant milk of choice (~1 cup)
1 tbsp of each: ground flaxseed, chia seed, hemp seed
1 tsp cocoa nibs (optional)
1 tsp maple or agave syrup (optional)
Cinnamon to taste
Berry Salad (blueberries, blackberries, strawberries, raspberries)
Fruit (orange, 2 kiwis, berries, grapes, cherries)
Raw or roasted (no oil) nuts or seeds: almonds, pumpkin seeds, 1 Brazil nut, walnuts
Chickpea Salad (put on top of a salad, eat with 2-3 Ryvita crackers, or have it as filling on a whole wheat pita or healthy, whole grain bread)
Sliced red peppers, grape tomatoes, celery, carrots & hummus
1 cup unsweetened plant milk of choice
½ frozen banana
½ cup frozen berries of choice
1 tsp hemp seeds, chia seeds, or ground flaxseed
Protein of choice: 0% plain Greek yogurt, plant protein powder, 1 tbsp natural nut butter, 2 tbsp unsweetened peanut butter powder
Kale & Cabbage Salad
Royall D, Smith MA, PEN (Practice-based Evidence in Nutrition). Immune System (Knowledge Pathway). 2019 Sep. Available through subscription.
National Institute of Health (Office of Dietary Supplements). Dietary Supplement Fact Sheets. Various dates. Available from: https://ods.od.nih.gov/factsheets/list-all/
This is for educational and informational purposes only and may not be construed as medical advice. The information is not intended to replace medical advice offered by physicians.