Coronavirus, immunity and diet
With the ongoing pandemic regarding coronavirus it is natural to wonder is there anything you can eat or drink to help prevent or treat the disease. You may have noticed there is a lot of information online claiming to be beneficial, but much of this is not true. Let’s look at the facts.
Firstly, we must remember that Coronavirus (or COVID-19) is a new virus- there has been very little research into it at this stage. Therefore, we do not know at this point whether there are any specific dietary interventions that will help protect against it. What we do know, is what nutrients are important for our immune system to work effectively.
Diet
There are a range of nutrients that are important to support our immune system including Vitamin A, Vitamin D, Vitamin C, zinc, and selenium. It is also important to consume enough calories and protein to optimise our nutritional status.
Vitamin A
Vitamin A is involved in the immune response in the body. It is also used in growth and for good eye function. Deficiency of Vitamin A is rare. Vitamin A is found in liver, oily fish, eggs, milk, carrots and broccoli.
Vitamin D
Vitamin D is necessary for a healthy immune system and to keep bones, muscles and teeth healthy. The body creates Vitamin D from the sunlight when we are outdoors. We can also get Vitamin D from dietary sources such as oily fish, egg yolks and fortified foods. Vitamin D deficiency is common, and supplementation may be necessary.
Vitamin C
Vitamin C is essential in the body for healthy skin, bones and blood vessels. It has a key role as an antioxidant and within the immune system.
Adults needs 40mg of Vitamin C daily, which can be achieved in the diet in sources such as kiwis, oranges, red and green bell peppers, broccoli and potatoes.
Zinc
Zinc is a key factor for our immune system, it also is involved in digestion, metabolism and is a powerful antioxidant. You should be able to meet your daily requirements for zinc in the diet.
Dietary sources of zinc include beef, lamb, chicken, milk, eggs and wholegrains.
Selenium
Selenium is an antioxidant and helps the immune system work properly. Selenium can be found in brazil nuts, fish, meat and eggs. Vegans are at risk of selenium deficiency.
Overall, the best way to support your immune system is to have a healthy and balanced diet. Tips to achieve this include:
- Eat at least 5 portions of a variety of fruit and vegetables every day – this will provide you with lots of vitamins, minerals and fibre and will help support a healthy gut
- Carbohydrates- choose wholegrains or higher fibre versions for each meal
- Protein source at each meal- meat, poultry, fish, eggs, pulses and dairy products. Pulses, such as peas, beans and lentils, are also a good source of fibre.
- Choose unsaturated oils and spreads such as those based on olive/vegetable/sunflower and include nuts and seeds in the diet
Deficiencies
Usually we can get all the nutrients we need from our diet. However, if you do have a diagnosed deficiency of a specific micronutrient it is important to get advice regarding supplementing this.
What else should we do to support our immune system?
Our immune system depends on both a balanced diet and having a healthy lifestyle.
Lifestyle
- Sleep- Get at least 8 hours of sleep every night to support your immune system1
- Stress- Try to keep yourself as stress-free as possible to prevent illness2.
- Physical activity- It has been found that people who are more physically active are less likely to suffer from infections such as the cold, and their symptoms are less severe3
- Good hygiene & hand washing can prevent the spread of a virus- do this regularly4
References
1Cohen S, Doyle WJ, Alper CM, Janicki-Deverts D, Turner RB (2009) Sleep habits and susceptibility to the common cold
2Cohen S1, Tyrrell DA, Smith AP (1991) Psychological stress and susceptibility to the common cold
3 Nieman DC, Henson DA, Austin MD, Sha W (2010) Upper respiratory tract infection is reduced in physically fit and active adults
4Jefferson T, Del Mar CB, Dooley L, Ferroni E, Al-Ansary LA, Bawazeer GA, van Driel ML, Nair S, Jones MA, Thorning S, Conly JM (2011) Physical interventions to interrupt or reduce the spread of respiratory viruses
Oxford Handbook of Nutrition and Dietetics 2nd Edition (2011) Edited by Joan Webster-Gandy, Angela Madden, and Michelle Holdsworth