Immune System 101 (Part 3): Nutrition & Your Immune System

Immune System series

Let’s start with the truth – no magical supplement, superfood or perfect diet plan can ensure you stay virus or disease free.  

But, there is some GREAT news for you.  Your daily habits can make a meaningful difference to your immune system.  

By consistently practicing healthy behaviors, you can:

A:  Help optimize your immune function over time


B: Prepare your body to fight off bacteria, viruses and other diseases. 

So let’s start by looking at the good food habits you can implement to support your immune system: 

1.  Avoid nutrient deficiencies by eating a balanced diet

A balanced diet consisting of a range of vitamins and minerals, combined with healthy lifestyle factors like adequate sleep and exercise and low stress, most effectively primes the body to fight infection and disease. 

Equally, a diet lacking in one or more nutrients can impair the production and activity of immune cells and antibodies (see for example, Childs CE, Calder PC, Miles EA. Diet and Immune Function. Nutrients. 2019 Aug 16;11(8).) 

Keep your processed foods to a minimum and wipe junk food out of your diet for good. 

A little tip, batch cook and freeze meals to make sure you have wholesome meals to hand at all times. 

Some of the key nutrients you need to support your immune system includes: 

Protein:  We discuss this in more detail below. 

Vitamin C:  Aids your immune system in fighting infections.  Good sources of vitamin C can be found in:  

  • Green leafy vegetables like spinach, bok choy, collard, mustard greens etc. 
  • Brocolli
  • Peas
  • Asparagus
  • Cauliflower 
  • Potatoes 
  • Parsley 
  • Citrus fruits such as lemons, oranges and satsuma 
  • Mango
  • Blackcurrants
  • Kiwi
  • Strawberries

Vitamin D:  See below for more details 

Zinc:  Supports T-cells. Since your body doesn’t produce it, you must obtain it through food (or supplements). Zinc obtained from animal foods seem to be better absorbed.  Check out these sources: 

  • Poultry e.g. Chicken and Turkey
  • Sesame seeds
  • Pumpkin seeds
  • Wild game
  • Crab
  • Beans 
  • Mushroom
  • Cashews 
  • Chickpeas
  • Almonds
  • Peas
  • Yoghurt
  • Oysters
  • Shrimp

Omega 3 fatty acids:  Omega 3 reduces inflammation and helps white blood cells to function well.  We recommend eating a plant source on a daily basis and oily fish for DHA/EPA 2-3 times per week. If you can’t manage this, we recommend a good Omega 3 supplement.  Here are the food sources for Omega 3: 

  • Chia seeds
  • Flax seeds 
  • Walnuts 
  • Salmon (better to get wild Salmon rather than farmed Salmon) 
  • herring (bloater, kipper and hilsa are types of herring)
  • pilchards
  • sardines
  • sprats
  • trout
  • mackerel

2.  Eat plenty of protein to flex your immune system 

Why have we given protein a whole section by itself?  Well guys, it is just that important!  You see, protein plays a vital role in every cell in your body. This includes your immune system and helping create the cells that help kick virus butt. 

People who are protein deficient are more susceptible to infectious disease.

As well as helping the immune system to develop and maintain the right antibodies, protein makes sure your immune system doesn’t go into overdrive.  

The amount of protein you need will vary depending on your activity levels and your optimal diet for health but as a starting point we recommend 1-2 palms for every meal.  

Some good sources of protein include:

  • Eggs
  • Seafood and fish (why not get a double hit and go for a Omega-3 rich oily fish) 
  •  Beef 
  • Chicken 
  • Turkey 
  • Pork 
  • Soybeans 
  • Whey protein 
  • Beans and rice or other blended meals 

Try, if you can, to choose organic, free range meats or their equivalent. 

3.  Vitamin D to stay disease free

There is one vitamin that is more important than the others when it comes to immune health.  Vitamin D.  

Plenty of research is coming out to say that a Vitamin D deficiency is linked to vulnerabilities in the immune system.  For example, researchers at the University of Colorado A have found that high doses of vitamin D reduce the incidence of acute respiratory illness (ARI) in older, long-term care residents.  

If you don’t live near the equator, consider a liquid supplement with 600-4,000 IU/day.  We cannot produce this vitamin naturally in our body so it is estimated that over 1 billion of us are suffering from a Vitamin D deficiency.  

If you can, get outside in the sun for 15-20 minutes per day.  If, like us, you live in the UK and you can’t rely on the weather to help, check out these food sources: 

  • Fatty fish rich in Omega-3’s, such as salmon or mackerel
  • Whole eggs
  • Mushrooms

We do recommend that you buy a good quality Vitamin D supplement to help with this. 

4.  Eat an appropriate amount of calories 

Having too much or too little body fat can interfere with certain compounds and sex hormones that affect immunity.  So it is really important to eat the number of calories you need to maintain a good weight or loss excess body fat.  

Check out this calorie calculator from Precision Nutrition which will help you to establish how many calories you need every day. 

5.  Limit alcohol 

Drinking regularly will have a negative impact on your immune system.  There is so much research on this and it all says the same thing.  Too much booze – and binge drinking – supress your immune system.  It leaves you open to everything from colds, flu’s, upper respiratory infections to slower recovery from injury.   

Too much alcohol can also mess with your gut flora, which is critical for a healthy immune system.  

If you drink every day, or in excess regularly, do the following:

A:  Remove all alcohol from your home.  Making it difficult to access alcohol makes it easy to drink less. 

B:  Schedule non-drinking days.  This creates boundaries and ensures you have a commitment to follow.  Start with the week days (as we know you look forward to that weekend tipple).  Build momentum by scripting easy victories first. 

C:  Record how much you drink on the days you do.  The chances are you will be surprised how many glasses you are having.  

Join us next time as we look at how to manage the biggest immune system killer – stress. 

Recent Posts

What being a Royal Marine Commando taught me about fitness

I am going to be honest. Being a Royal Marine Commando taught me more about health and fitness than all of my personal training courses combined. That’s no criticism of the teaching, rather a nod to the fact that health and fitness is a way of life in the Royal Marines because our lives depended on it.

Read More »
Body fat loss Transformation

Jeremy’s transformation

Saxony was desperate to lose weight. At 40% body fat, she felt unhealthy and nowhere near her physical potential. She had trained with a number of personal trainers before but they couldn’t help her achieve the transformation she wanted. Here’s how she got down to 20% body fat in just 16 weeks

Read More »
How to train when you are busy

How to make time for exercise when you are really busy

Most of us will struggle to find the time for exercise occasionally, and that’s perfectly ok – life happens. As a business owner and parent, I understand how time constraints can impact your health and fitness. I often have to remind myself that my health and fitness directly contribute to my business productivity and life.

Read More »