The Immune System: How to Keep it Healthy and What You Should Eat

It's winter, which means cold and flu season— what a delight! We've had some cold and flu shenanigans in our household, so I thought it might be time to discuss nutrition for the immune system. 

Here we go! 

An Introduction to the Immune System

The immune system is complex and fascinating. It is the body's natural defence against foreign invaders, like bacteria and viruses.

The immune system has two main parts: the innate and adaptive immune systems. The innate immune system responds to threats immediately, while the adaptive immune system takes time to produce antibodies that can destroy specific pathogens.

If this all sounds like an intergalactic scene from Star Wars, you're on the right track!

The innate immune system is made up of cells that are found throughout the body. These cells release chemicals called cytokines to kill or stop the growth of harmful microorganisms in their tracks. Cytokines also help recruit other cells to fight off an infection.

When we get sick, it means that there is something in our environment that our body's defences can't handle on their own. This could be because our immune system weakened or we have been exposed to too many germs at once (like can happen during cold and flu season).

How Nutrition Affects Our Immune System

Stress, lack of sleep, and eating certain foods can all influence our immune systems. Nutrition from foods we eat all help to contribute essential nutrients like vitamins, minerals, and antioxidants to assist all the different parts of the immune system is functioning at their best. These nutrients can help your body fight off infection and disease. But what does this actually mean?

Let's check how different food groups can support our immune systems.

1) Fruits and Vegetables

Fruits and vegetables are rich in vitamins, minerals, antioxidants and other nutrients essential to maintaining a healthy immune system.

Fruits and vegetables provide the body with an array of antioxidants, minerals and vitamins that help the immune system. These include Vitamins A, C, E and K; minerals such as potassium, magnesium and zinc; and fibre which helps keep the digestive tract healthy.

Try to enjoy a wide variety of fruits and veggies in different colours. For example, orange veggies like carrots and sweet potatoes contribute Vitamin A. Fruits and veggies don't need to be fresh. Frozen fruits and veggies are just as great for you.

2) Protein-Rich Foods

Protein is not only crucial for muscles but also for a healthy immune system. Protein-rich foods provide amino acids, the building blocks for muscle, skin and other tissues in our bodies. Protein helps build antibodies that are needed to fight off infections and illnesses. When you have enough protein in your diet, it can also help your immune system function.

Animal protein sources like meat, fish, eggs and dairy foods are complete protein sources. This means that they provide all essential amino acids needed by our bodies. Plant protein sources like nuts, grains, and legumes are in-complete protein sources. This just means that 1-2 amino acids are missing, so mixing up your plant proteins to get all the essential amino acids your body needs is good. 

3) Wholegrains

Wholegrains foods also contain dietary fibre, which helps to keep everything moving through the digestive system. This helps ensure that the whole digestive tract is healthy and functioning well, which is especially important for immunity because it can help reduce inflammation in the gut lining, which may lead to a healthier immune system over time.

You can explore and experiment with many different wholegrains in your cooking. Brown rice is a great staple in the pantry as a side for many dishes, for example. Quinoa is excellent for salads, or add a sprinkle of pearl barley in your next batch of soup. 

What about Supplements?

There is evidence that supplementing your diet with Zinc, Vitamin D and Vitamin C if needed, can help support your immune system. Zinc has been shown to reduce the severity of colds if taken at the right time, that is. There's also been a ton of evidence surrounding the effect of Vitamin D on the immune system. Given that we're likely to get less Vitamin D from the sun in winter, it's a good idea to chat to your doctor or dietitian about the benefits of supplementing your diet. If you eat enough fruits and veggies, you'll likely be getting enough Vitamin C through these foods.

Here's to avoiding those dreaded lurgies this winter.