There’s never been a more important time to ensure your immune system is in the best shape it can be. Helen Foster has the tips to help you do it...

1. Eat right

There are some things that impact your immunity that you can't control, like your generics, but others that you can. Everyone has the power to maintain a healthy weight, and eat a nutritious diet. ‘The immune system uses a lot of energy to protect you, and the foods you eat supply the calories, proteins, fats and other building blocks you need to fuel this.’ says Philip Calder, professor of immunology at the University of Southampton. Professor Calder recommends ‘a healthy, diverse, well-balanced diet with plenty of plant-based foods – fruits, vegetables, berries, nuts, seeds, pulses – plus some animal-based foods that supply certain nutrients, like oily fish for omega 3s and meat for vitamin B12.’ This diet helps to create a healthy balance of bacteria in the gut - a stepping stone to positive immune function. 

2. Take supplements

Even a good diet might not provide enough of one vital immune nutrient – vitamin D. ‘This helps immune cells function and it is important in both antibacterial and antiviral defences. We also know high levels of vitamin D in the blood are associated with a lower risk of contracting respiratory infections - and it's suspected it might reduce the risk of Covid-19 too,' says Professor Calder. Normally we make vitamin D from sunlight, but this doesn’t happen during winter; everyone should take a supplement of 400iu vitamin D3 daily from October to March.

3. Wash your hands

Hand washing has become the new normal for good reason. A new study by University College London found that handwashing six to 10 times a day reduced risk of infection with coronavirus by 36 per cent; similar protective effects have been shown against colds and flu. ‘We become infected with these illnesses when droplets from an affected person fall onto a surface that we touch – and we then touch our hands or face. Handwashing breaks the chain of infection,’ says Professor Sally Bloomfield from the London School of Hygiene and Tropical Medicine. Be diligent in the morning – infection happens when a virus that enters our body replicates faster than your body can fight it off, and research from the University of Cambridge found viruses multiply 10 times faster in the morning.

4. Cut back on salt and sugar

For optimum immunity, reduce your intake of sugar and salt. Sugar upsets the balance of gut bacteria that play a role in immune defence, while researchers at University Hospital Bonn in Germany discovered that high levels of salt weaken the ability of special immune cells – known as granulocytes – to destroy bacteria. Try not to eat more than 5-6g of salt a day – that's about one teaspoon - or more than 30g added sugars (including the sugar in honey, fruit juice or syrup).

5. Get some sleep

Three times - that's how much a study at the US's Carnegie Mellon University found your risk of catching a cold increases if you sleep less than seven hours a night, compared to those who sleep eight or more. ‘If you’re lacking sleep, your ability to produce new immune cells is compromised and those you do have don’t work as effectively,’ says Dr Jenna Macciochi, immunologist and author of Immunity: The Science Of Staying Well (Harper Collins, £14.99). ‘But quality of sleep also counts. Waking often in the night interferes with the deep sleep during which our body does much of its repair work.’ She suggests a regular sleep and wake time to help reset your body clock, and, if you wake up a lot at night, check your sleep environment. If it's too light, too hot, too cold or too noisy, you're more likely to have poor quality sleep. 

6. Stock up on echinacea

There are lots of supplements that claim to boost immunity, but scant evidence that they work. However, according to viral immunologist Dr Ross Walton, echinacea is the real deal. ‘A 2006 review of previous clinical studies using echinacea concluded there was potential for its use in preventing colds, particularly if you are stressed, travelling long distances or living in a household where people smoke,’ he says. Further research at Cardiff University found people taking echinacea cut their risk of catching a cold by 53 per cent. Dr Walton says the herb seems to alter the cells in our airways in a way that makes it harder for viruses to stick to them. For best results, take a daily dose of a good quality product like A. Vogel Echinforce (£11.95 for 40 tablets from Holland and Barrett) throughout winter.

7. Stop trying to hard to be healthy

Eh, what? Surely, the more you can do the better, right? ‘But if you’re worrying about whether you’re eating the right foods, getting enough exercise, doing everything you can, you actually create low levels of stress in your body which adds to our normal stress load – and stress suppresses immunity,’ says Dr Macciochi. It might also help to limit social media right now. Not only does Dr Macciochi say it can cause a lot of comparison stress, but US researchers found reading about a pandemic on social media causes more worry about risk than reading news in traditional media.

8. Facetime a friend

The genes that control the part of your immune system that fights viruses don’t work as effectively if you feel lonely, say US scientists. If you can’t meet friends, try video chatting instead. ‘Our research found anything with video is 100% better at creating connections than either the phone or text-based media. It creates a greater feeling that you are in the same room together,’ says Professor Robin Dunbar from the University of Oxford. ‘It also enhances the "flow" of your interactions because you can see the smile breaking (or not!) on the other person's face before you've even finished the joke.'

9. Get moving

Exercise like running, cycling and walking helps fire up your immunity, ‘but just as important as getting regular bursts of formal exercise is just moving your body throughout the day,’ says Dr Macciochi. ‘Moving stimulates the lymphatic system, which is the circulatory system for your immune cells, and this helps maintain the flow of immune cells around the body.’ Try and walk around for five minutes every hour – or do some simple muscle clenching moves at your desk.

10. Be optimistic 

Researchers at the University of Kentucky found that summoning up positive feelings about the future triggers a temporary bump in immunity. And if thinking positive seems a little tricky right now, Sandra Horley, clinical psychotherapist at Healingclouds. com, suggests an exercise called the Jaw Drop. ‘This allows the calming autonomic nervous system to restore balance in the body,’ she says. To do it, close your eyes, put your fingers below your ears and underneath your jaw bone and think about what’s making you feel low. Open your mouth and allow your jaw to drop. You'll experience a slight stretch in your cheek muscles. Then drop your jaw lower – you should feel a tightness in your cheeks and the back of your jaw. Hold for a second or two, then relax; your anxiety will fade.’ Immune boosting and instantly calming? That sounds like a move that's pretty helpful right now.