How to support your immune system this winter

How does the immune system work?

Our immune system is our mode of defence against intruders from the outside world. The immune system is able to differentiate between the body’s own cells and foreign antigens. This includes viruses, bacteria, fungi, foreign tissue, and toxins.

White blood cells recognise antigens and try to eliminate them. As we interact with our environment, the immune system becomes better and better at recognizing these antigens and keeping us healthy.

The immune system has two parts:

  • The innate immune system. Also called the non-specific immune system, this uses cells called natural killer cells and phagocytes to fight off antigens that enter the body.
  • The adaptive, or specific, immune system. This makes special proteins called antibodies, which are able to attack intruders that they recognize. Once you have antibodies against a particular virus or bacteria, that particular virus can’t make you sick again. This immunity may last for years, and in some cases, will last for life.

What foods should I eat to maintain a healthy immune system?

A balanced diet in general is important for your immune system. A few specific foods can help ensure you’re getting the right amount of vitamins, minerals, antioxidants, proteins, and healthy fats to keep inflammation low and support your immune system.

This includes:

  • colourful fruits and vegetables, which are high in antioxidants, vitamins, and minerals
  • healthy fats, like those found in olive oil, avocado, and salmon
  • fermented foods, such as yogurt, sauerkraut, kimchi, and kefir
  • foods high in fibre, including whole grains and legumes
  • herbs and spices, such as turmeric, black pepper, garlic, and ginger
  • nuts and seeds, especially walnuts and flax seed
  • dark chocolate
  • green tea

What foods should I avoid?

Certain foods may increase inflammation in your body.

Try to avoid the following foods, which can increase inflammation:

  • foods with added sugars, junk food, and fast food
  • artificial trans fats, which are often added to processed and fried foods
  • refined carbohydrates, which are found in white bread, pasta, pastries, cookies, and cakes
  • processed meat

It’s also a good idea to limit your alcohol consumption.

Should I take a supplement?

Certain supplements may help support your immune system. However, as their name suggests, they should supplement — not replace — your healthy lifestyle.

Some people, particularly older adults, may be deficient in nutrients, such as vitamin C, vitamin D, and zinc, and may benefit from supplements.

For instance, your body doesn’t produce or store vitamin C, so if you don’t get the recommended daily amount from your diet (80mg for adults in the UK) you may want to take a supplement. However, it’s important to ask your doctor before taking any new supplements.

How much sleep do I need?

Adults need roughly 7 to 9 hours of sleep per night. This varies from person to person. However, getting less than 7 hours of sleep per night on a regular basis may weaken your immune system.

Sleep deprivation keeps the immune system from building up protective, substances like antibodies and cytokines.

Should I lose weight?

In those with obesity, losing weight could make a big difference in the overall immune system.

Obesity has been linked to an impaired immune response. While the cause of this isn’t fully understood, scientists do know that one characteristic of obesity is a state of chronic inflammation.

Lowering your overall calorie intake, getting some exercise, and increasing the amounts of fruits and vegetables in your diet are the first steps if you believe you need to lose weight. Talk to your doctor if you’re unsure where to begin.

Can exercise help my immune system?

Yes, moderate exercise is an excellent way to support your immune system. Try to aim for 30 minutes per day for 5 days of the week, or 150 minutes per week total. Include a mix of cardio and strength training exercises.

Does smoking hurt my immune system?

Yes. Smoking can negatively your immune system.

Research also shows that smoking may upset the balance of your immune system so much that it can increase the risk of some immune and autoimmune disorders. An autoimmune disorder occurs when the immune system mistakenly attacks your body’s healthy cells.

What else can I do to strengthen my immune system?

Reducing stress can make a big difference in your immune system functioning.

A few ways to reduce stress include:

  • meditation
  • yoga
  • nature hikes
  • listening to music
  • massage
  • aromatherapy

Other things you can do to stay healthy:

  • Wash your hands with soap and water for at least 20 seconds frequently throughout the day, but especially before eating and after using the bathroom.
  • Avoid touching your face.
  • Avoid large crowds.


There are many ways to keep your immune system healthy, including eating well, exercising, and getting enough sleep.