A healthy immune system is central to your body's ability to fight off any nasty bacteria that comes your way.

With the long and cold nights of winter fast approaching, building up your immune system now will help protect you from the influx of colds and flus that are guaranteed to rear their heads.

Give your immune system a head start by incorporating these healthy, nutrient-rich foods into your diet.

1. Garlic

Praise hallelujah, another reason to include garlic in every dish you make! Garlic contains an active ingredient called allicin which helps fight infection and bacteria. Research shows that it also helps to lower cholesterol levels.

How to eat it: Add raw garlic to things like avocado, salad dressings and butter. Add crushed garlic cloves to pretty much any dish you're cooking. Garlic is always a winner.

2. Mushrooms

Mushrooms are known to increase the production and activity of white blood cells, making them more effective at fighting infection. Shiitake and reishi mushrooms are said to be the most beneficial, but everyday closed-cap mushrooms will still do the job.

How to eat them: Not everyone is a fan of wild mushrooms due to the different textures. If you find that you don't enjoy chewier types of mushrooms the best way to incorporate them into your diet is to make a mushroom soup with all different strains of mushrooms and blend it.

3. Chicken Soup/Broth

We thought it was a myth that giving a sick person chicken soup would help them, but apparently not. When chicken is cooked an amino acid called cysteine is released. Cysteine is actually really similar to a drug that is used to treat bronchitis. Furthermore, the salty broth of the soup helps to reduce mucus levels in the same way that cough medicines do.

How to eat it: None of the canned stuff. Make authentic, home-made chicken soup and add garlic and onions for an extra immunity-boost.

4. Tea

Good news for tea drinkers! Research has shown that people who drink black tea have 10 times more virus-fighting properties in their blood than those who don't. Green tea is even healthier for you than black tea due to the abundance of anti-oxidants.

How to drink it: The study showed that several cups of tea a day, up to 5 cups, really benefited the immune system. Bobbing the tea bag up and down while it brews unlocks even more antioxidants.

5. Red Bell Peppers

Not many people know this, but red bell peppers have twice as much vitamin C as citrus fruits such as oranges and lemons. Vitamin C is a go-to for getting rid of the cold and building up your immune system.

Red bell peppers are also really high in beta carotene, which is basically vitamin A, another great vitamin to strengthen up your immune system.

How to eat them: Where possible, it's always better to eat fruit and vegetables raw because many of the vitamins and minerals present are lost during cooking. Snack on red pepper strips and hummus or add them to a salad.

6. Natural Yoghurt

Not the tastiest form of yoghurt out there, but definitely the healthiest. Natural yoghurt with live and active cultures is a probiotic, meaning it contains good bacteria. We all need some good bacteria to fight the bad bacteria.