Can I improve my immune system?

It's a question a lot of us must be asking ourselves following a winter of widespread illness. So far its been a season of coughs, colds and full blown flu. If you've avoided it thus far well done, you're in a minority!

So how can we help ourselves to stay healthy when everyone around us seems to be succumbing to the germs?

Our immune system is key to our defence against invading pathogens like viruses and bacteria, it's made up of two parts, the innate and the adaptive immune system. The former is a non-specific response to germs while the latter is acquired through memory of a previous attack. This allows for a specific and targeted immune response.

While we use terms like 'immune boosting' to describe certain foods and supplements what we're really referring to is taking action to support optimal functioning of the immune system and there are certainly dietary factors that play a role in our immune health.

Vitamin C

This is a popular and very well known one for combating the common cold! Vitamin C is in fact a very powerful antioxidant and is found in abundance in many fruits and vegetables. 

Research has shown us that vitamin C can't prevent the common cold as once thought but it can reduce the length and severity of the illness. It's important to note however that you need to have been taking vitamin C regularly before the sniffles start for it to be effective. 

Good dietary sources of vitamin C (as listed on the NHS website) include citrus fruit, peppers, strawberries, blackcurrents, broccoli, brussels sprouts and potatoes.

Zinc

Zinc deficiency has been found to negatively impact many cells related to the innate and adaptive immune system.

As with vitamin C, research has shown that while it cannot prevent the onset of a cold if Zinc is taken within 24 hours of the symptoms starting then it can reduce the severity and length of the illness.

Dietary sources of zinc include shellfish, red meat, eggs, nuts, seeds, lentils, chickpeas and whole grains.

Vitamin D 

There is a link between vitamin D deficiency and autoimmune disorders therefore it is thought that vitamin D is required for a healthy immune system.

It is extremely difficult to get enough vitamin D from food sources alone, the primary source is via skin exposure to the sun. This means vitamin Vitamin D deficiency has become a big problem in the countries found in the northern hemisphere where our hours of sunlight are limited. It is further exacerbated by lives increasingly being led indoors - think young people glued to video games and an ageing population living inside their own homes and care homes.

Public Health England advise that everyone needs vitamin D equivalent to an average daily intake of 10 micrograms. Supplementation is particularly important during the winter months.

Dietary sources of vitamin D include oily fish, red meat, liver, egg yolks and fortified foods such as fat spreads, breakfast cereals and dairy products.

Vitamin A

If you're lacking vitamin A then you could be running a higher risk of becoming infected with a bug - this is because a deficiency is linked with a weakened immune system.

Vitamin A is found in two forms in our diet, as retinol or carotenoids. Retinol is found in animal sources such as milk and liver while carotenoids are found in brightly coloured fruits and vegetables such as carrots, sweet potatoes, spinach and kale. If you feel your diet is lacking then you could address the shortfall by opting for a vitamin A supplement.

It's important to note that vitamin A supplementation is to be avoided if you're pregnant.

Garlic

Scientific research has shown that 600-1200mg of aged garlic extract can help to lessen the risk of developing a cold or infection. Garlic  is believed to increase T cell production - a type of cell that plays a central role in the immune response.

Garlic also helps white blood cells to fight harmful pathogens. More specifically the help comes from a chemical compound called allicin, which is found in garlic cloves when they are crushed or chewed. This allicin, which contains sulphur, transforms into other compounds which are beneficial to your army of white blood cells, helping them chase down and fight off pathogens.

Probiotics

Our immune cells, in the main, live in our gut and an increasing amount of research is supporting the idea that boosting our overall gut health in turn supports a well functioning immune system. It all quite new in its concept so while exciting there is yet to be any approved health claims as far as the impact of probiotics on the immune system.

Probiotic foods include yoghurt (check the label for 'live active cultures'), kefir, sauerkraut, tempeh, kimchi, miso, kombucha, fermented pickles (not the ones made with vinegar) and natto.

And the others:

While the following can certainly be beneficial to the immune system and many find they make a difference, there is less science that says so definitively:

• Echinacea
• Elderberries
• Spirulina
• N-acetylcysteine supplements

Needless to state we can help ourselves to stay healthy by getting good sleep, exercising on a daily basis, managing our stress levels, avoiding excessive amounts of sugar and alcohol and practicing good hygiene habits.

Here's hoping that the rest of 2020 is healthier!