Can food protect us from the flu?

When it comes to navigating flu season, we often gravitate towards universally accepted staples: bottles of vitamin supplements, bowls of steaming chicken soup and cups of herbal tea.

These aren’t unfounded myths, though. Eating well is a major part of our defence system and offers our body greater resistance to bugs and viruses – including influenza and even COVID-19¹.

You probably know that proper nutrition helps with your immune system, but have you ever wondered what takes place at the microscopic level? Let’s dive in.

Before we discuss food, let’s review our immune system, which is comprised of two types of immunity²:

1. Innate immunity. This is our first line of defence against pathogens (an organism that can cause or create disease in its host) and includes our skin, stomach acid, mucus and more.
2. Adaptive immunity (or acquired immunity). When any foreign substance enters our body, white blood cells and organs including the spleen, thymus and lymph nodes produce antibodies. These antibodies are specifically shaped to bind to the substance and destroy it. Our immune system then ‘remembers’ the genetic structure of the foreign entity, so if it ever returns, our antibodies will be more efficient in responding to the threat.

Fruits and veggies are essential in a balanced diet for their nutritional content. These food groups are packed with vitamins and minerals, which help your body and immune system perform at their peak³.

Think of vitamins and minerals as your body’s maintenance crew – while they generally don’t fight infections directly, they help your adaptive immune system produce antibodies and white blood cells to destroy pathogens⁴.

There are plenty of vitamins, and you’ve probably heard of most of them; A, B6 and B12, C, D and more. Each vitamin serves a range of different purposes. Vitamin D supports healthy bone structure and protein production⁵, while vitamin C can be helpful in recovering from respiratory viruses like the common cold, influenza and COVID-19⁶.

Our body also requires trace amounts of minerals for a healthy immune system. For example, a mineral like zinc is involved in healing wounds, synthesising new DNA and proteins and can even reduce cold symptoms.

Most importantly, our bodies are unable to create these vitamins and minerals on its own – which is where a healthy, balanced diet comes into play.

According to the official New Zealand dietary guidelines⁷, we need at least five serves of vegetables and two serves of fruit every day. These two food groups are bursting with vitamins and minerals and should be staples in your diet⁸:

Fruits:

• Apples, pears and bananas
• Citrus – oranges, grapefruits, mandarins, limes
• Berries – strawberries, raspberries, blueberries, kiwifruit and passionfruit
• Melons – watermelons, rockmelons, honeydew
• Tomatoes and avocadoes

Vegetables:

• Leafy greens – spinach and silverbeet
• Cruciferous – cabbage, cauliflower, brussels sprouts and broccoli
• Marrow – pumpkin, cucumber and zucchini
• Root – potato, kumara and yam
• Edible plant stems – celery and asparagus
• Allium – garlic, onion and shallot

While supplements, teas, fruits & veggies play their part in boosting your immune system, there are other ways to help your body achieve optimum immunity.

To prime our bodies against infection and diseases, we need to take a holistic approach to our health by making healthier lifestyle choices. These include getting enough sleep, exercising regularly and maintaining low stress levels throughout the day⁹.