The past 18 months have highlighted how vulnerable our health can be and how important our immune systems are. The threat of Covid-19 is still as present as ever, and now that the clocks have gone back and winter has truly arrived (bringing with it all of the winter colds and flus),our immune systems will be as important as ever for protecting our health.
Bearing this in mind, many people have promoted certain foods and products claiming to have the power to “boost” our immune systems. As wonderful as it would be if one food could magically doth is, it is unfortunately not possible. There is no magic wand and no such thing as an “immune booster”.
However, nutrition does have a vital role to play in a healthy immune system and certain nutrients are needed for it to function normally. As the old saying goes, prevention is better than cure. So, ensuring that you include sources of these nutrients in your diet now maybe beneficial for your overall health and for a healthy immune systemin the coming weeks and months.
As is the case with many aspects of nutrition, what you eat day in and day out will have the greatest influence on your health. The focus should be on maintaining a varied, balanced diet, rather than one specific food eaten once in the blue moon!
What nutrients are important for immune function and how we can obtain them through our diet?
Vitamin A plays a number of different roles in the immune system. It is involved in regulating cell cycles in the body. In this way, it plays a role in maintaining healthy skin, which is the body’s first line of defence against infection. It also has effects on white blood cells that are involved in the immune system’s response to infection.
There are two main forms of vitamin A in our diet. Retinol is found in animal sources such as eggs, milk and oily fish, including tuna and herring. Beef liver is a particularly high source of retinol. Carotenoids such as beta-carotene can be obtained from plant foods and converted to vitamin A in the body. Sources of beta-carotene include spinach, kale, sweet potatoes, peppers, mangoes, melons, carrots and papaya. If you are trying to include more carotenoids in your diet, choose brightly coloured fruit and vegetables!
Vitamin C is an antioxidant. It takes part in a number of different chemical reactions in the body, called redox reactions. It is involved in regulating different parts of the immune system, including certain types of white blood cells that are involved in the immune response to infections.
Foods that are high in vitamin C include vegetables such as peppers, cabbage and cauliflower and fruit such as kiwis, oranges, grapefruit and blueberries. Some herbs also contain vitamin C, including parsley and chives.
Vitamin D is another important vitamin for maintaining a healthy immune system. We produce it from sunlight shining on our skin, but unfortunately during the winter months we cannot make enough of it in this way. This is why it is recommended to take a 10mcg supplement of vitamin D daily in the UK between the months of October and March. Food sources of vitamin D are limited, but they include eggs and oily fish.
There are a number of different B vitamins. Those that are important for our immune function are folate, vitamin B6 and vitamin B12. Folate is found in green vegetables such as spinach, Brussel sprouts and asparagus. Vitamin B6 can be obtained from a number of sources including chickpeas, potatoes and bananas. Meanwhile, vitamin B12 can be found in milk, dairy products and beef, among other sources.
Zinc is a mineral which plays an important role in our immune function. It is a catalyst for approximately 100 different enzymes in our bodies. Zinc is required for the development of certain white blood cells that are needed for the functioning of the immune system. Foods that are high in zinc include shellfish and red meat, such as beef and pork. Oysters are a particularly high source of the mineral. Milk, dairy products, peas and beans also provide some zinc.
Selenium is involved in the immune system in a number of ways, including regulating the cycle of different cells and reducing inflammation. Foods that are high in selenium include fish such as tuna and sardines, meat and poultry, nuts, milk and dairy products. Brazil nuts are particularly high in the mineral, with one Brazil nut providing an adult’s recommended daily amount of selenium!
Copper is another mineral which carries out a number of different roles in our body and contributes to the functioning of our immune system in this way. There is a wide range of sources of copper, including potatoes, turkey, cashew nuts and sunflower seeds.
Clearly, there are numerous different nutrients involved and a wide range of foods that they can be obtained from. As usual, the take-home message from all of this is that a healthy, varied and balanced overall diet is the best approach to help you and your immune system!