Immune boosting nutrients 101

Posted on 30 June, 2020

With cold and flu season in full swing (let’s just not mention COVID, hey?), Nutritionist Kate Freeman looks at what our diet can do to assist our immune response.

It’s no secret that a healthy diet results in a stronger immune system. But what vitamins and food do we specifically need to defend our bodies against colds and flu this winter?

Vitamin C

Research shows that adequate intake of vitamin C can build a healthy immune system and defend your body against disease.

It probably won’t stop you from catching a cold, but you’ll be more likely to recover from it quicker and experience milder symptoms.

Vitamin C helps fight infection by:

• Stimulating our immune system to produce interferon (a natural anti-viral)
• Activating our white blood cells
• By helping in the production of antibodies.

Vitamin C is one of the most bountiful vitamins found in fruit and vegetables and as such it’s really easy to meet your body’s requirements. Vitamin C is best eaten through whole foods and the fresher the food is the higher the vitamin C content. The longer the fruit and vegetables are in storage or at room temperature the less vitamin C they contain.

The RDI (recommended dietary intake) for adults is 45mg of vitamin C per day. One medium-sized orange has approximately 69mg of vitamin C so one orange a day will definitely help keep the doctor away!

Other meal and snack ideas to ensure sufficient vitamin C intake are:

• Bruschetta: Chop up 2-3 fresh tomatoes, 1/2 Spanish onion and a handful of fresh basil leaves. Combine with a dash of olive oil and balsamic vinegar and serve on top of toasted turkish bread or sourdough. Serves 2. Contains 50mg vitamin C per serve.
• Fruit salad: Chop up 1 banana, 1 apple, 1 cup strawberries. Add 1 cup grapes and 1 cup blueberries. Toss in 1/4 cup freshly squeezed orange juice. Serves 2. Contains 75mg vitamin C per serve
• Steamed vegetables: 1 cup broccoli florets, 4 Brussels sprouts, 1 cup peas. Serves 2. Contains 90mg vitamin C per serve

Other recipes to try:

• Vegetarian Pad Thai
• Asian Greens with Oyster Sauce
• Chicken & Vegetable Soup

Other sources of vitamin C to eat regularly:

Oranges, mandarins, lemons, limes, rockmelon, honeydew melon, cherries, kiwi fruit, mangoes, papaya, strawberries, tangelo, tomatoes, watermelon, cabbage, broccoli, brussels sprouts, bean sprouts, cauliflower, kale, mustard greens, red and green capsicums, peas and potatoes.

Beta carotene

Beta carotene is known as pro-vitamin A. This means that when you eat beta-carotene it gets converted into vitamin A by your liver.

Research shows that adequate intake of vitamin A can actually help prevent colds and flu from even taking hold. This is because vitamin A protects our mucous membranes.

Sound a bit technical? Mucous membranes line our mouth, nose, throat and breathing passages and thus strong mucous membranes are more resistant to viruses and bacteria that can cause infection there. It is also involved in the production of tears, saliva and sweat which also contain antiviral and antibacterial properties.

Beta carotene is generally found in yellow or orange vegetables. It’s so abundant in these vegetables that you’ll have no problems in meeting your body’s vitamin A requirements.

The RDI for adults is 900ug of vitamin A per day for men and 700ug of vitmain A per day for women. One large carrot has approximately 1200ug so one carrot a day will also help keep the doctor away!

Other meal and snack ideas to ensure sufficient vitamin A are:

• Pumpkin soup: Saute 1 chopped onion and 1 crush garlic clove in a little dash of olive oil. Add approximately 600g chopped, skinned pumpkin and cover with 2 cups of water and 2 cups of salt-reduced chicken stock. Simmer until pumpkin is soft. Blend until smooth. Serves 2. Contains 1300ug of vitamin A per serve.
• Snack platter: Serve chopped carrots, celery, capsicum, zucchini and broccoli florets on a platter with hummus, natural yoghurt and other low-fat dips. Serves 4. Contains 400ug vitamin A per serve.
• Sweet potato chips: Cut up 1 large sweet potato into chunky chip-sized batons. Steam or microwave them until just soft. Spray them with olive oil and toss in sea salt and Spanish paprika. Cook on a BBQ or chargrill until crispy and serve with a fresh garden salad and BBQ’d meat. Serves 4. Contains 600ug vitamin A per serve.

Other recipes to try:

• Pumpkin and Spinach Muffins
• Hearty Pumpkin Soup

Other sources of Beta-carotene to regularly eat:

Carrots, sweet potato, spinach, grapefruit, brussels sprouts and broccoli.

Lycopene

A final defender against colds and flus is lycopene.

This a phytochemical found fruits and vegetables with a number of health benefits including the building of a healthy immune system.

• Try some fresh grape or cherry tomatoes in my Lemon Tomato & Basil Pasta
• Add shredded kale to my Chicken and Vegetable Stir Fry

Other sources of lycopene to regularly eat:

Tomatoes, cherries, red capsicums, watermelon, kale and strawberries.