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How to keep your immune system healthy over the winter and avoid colds

Our President, Professor Peter Openshaw, appeared on the BBC Radio 2 Simon Mayo Drivetime programme on 4 January answering questions about how to keep your immune system healthy and how to avoid colds. Here, he discusses some of the questions asked in more detail.

What is the immune system?

Tissues, mug of tea, thermometer and cough medicine

It’s all the things that our bodies use to fight off infection: antibodies, cells and so many other things that keep us healthy. In general, the immune system does an amazing job of putting up with the harmless germs that live in us and on us while identifying and expelling those more harmful species that can cause illness and disease.

What can you do to avoid getting colds?

You might be able to avoid a cold by wearing full protective equipment, but in the end the cold viruses will probably find a way to get you. There are so many viruses that have evolved to cause colds – perhaps 200 or more. It’s hard to see how we can ever defeat all of them. They spread from person to person via small droplets sneezed or coughed into the air, or by mucus that gets onto hands and onto surfaces. You can take sensible steps to decrease the risk of transmission, such as washing your hands and not sneezing or coughing over people.

Why do kids get so many colds?

The immune system needs to learn: it needs to build up experience. Just like we go to school to learn facts, we also go there to pick up germs.

Our immune system is very clever in that it has a built-in memory. For example, when it has come across a virus once, the immune system usually retains a ‘memory’ of how it got rid of that virus from the body. If it comes across the same virus later in life, the immune system can bring back this ‘memory’ and attack and defeat the virus before it makes you ill.

Does getting colds make the immune system stronger?

Yes, probably. Your immune system is designed to fight off infections and keep the body healthy; common infections put our immune system through its paces. In germ free environments, the immune system performs very poorly: it needs germs to keep in trim.

Jar of pills

Do common cold remedies work?

Most of them just relieve the symptoms of a cold (like headache, sore throat or fever), or act as a placebo rather than attacking the actual cold virus. They buy time while the immune system gets rid of the cold viruses. Menthol inhalers or ointments make you think there’s more airflow through the nose so they also make you feel better.

What can you do to boost the immune system?

It’s a nice idea, but the evidence that you can boost your immune responses by doing something or taking supplements or eating a certain food is elusive and makes little scientific sense. The immune system is your body’s built-in defence system to protect you against harmful bacteria and viruses and it carries out this function very well most of the time.

If you could boost your immune system and it’s working well already, that might make you more ill. Immune overactivity is as dangerous as immune underactivity. For example, an overactive immune system (which attacks inappropriate substances such as pollen grains or your own body’s cells) causes conditions such as allergy and autoimmune diseases like rheumatoid arthritis. Living a healthy, balanced lifestyle is the best thing you can to do make sure your immune system can function optimally.

How about lemon juice or vitamin C? Echinacea? Ginseng?


According to some studies, Ginseng and Echinacea may actually work but we don’t know how and the evidence is not really firm. More studies are needed (you can find more information on Echinacea in this NHS Choices article). The effectiveness of huge doses of vitamins (especially vitamin C) has been researched, but findings currently indicate that they don’t work, are expensive and can be harmful. Ordinary vitamin supplements are fine if you are deficient, but on a good normal diet you will get enough vitamins anyway. It makes more sense (and is cheaper) to eat a healthy, balanced diet than to take vitamins.

How about probiotics?

It’s possible that supplementing your ‘friendly bacteria’ with probiotics will be helpful, but the science is still in progress. The quality of probiotics needs to be well standardised (which isn’t always the case currently), and it’s possible that what helps some people may not help others. There is a lot to learn, and this is a very active field of research.

Should I have a flu vaccine?

If you are offered it, take it. Flu vaccines are about 65% effective, but only generally work for one season. It’s particularly important that anyone at a higher risk of developing complications from flu receives a vaccine – this includes anyone aged 65 and over, people with an underlying health condition and pregnant women.

And some final thoughts…

Live healthy:

  • Don’t smoke: it damages your lung’s ability to clear infection
  • Do some moderate exercise every day
  • Get enough sunlight
  • Eat a balanced diet including fresh fruit and vegetables
  • Don’t drink too much and avoid being overweight
  • Get adequate sleep and find ways to cope with stress

Good luck!

Peter Openshaw, President, British Society for Immunology

You can listen to Peter’s full interview on the BBC Radio 2 Simon Mayo Drivetime programme at 16 mins 40 secs into this recording.

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