A healthy, varied diet is key. “Fruit and veg contain immune-friendly phytochemicals, and some vitamins and minerals appear to boost defenses,” says nutrition scientist Dr Emma Williams. “These include vitamin C and vitamin A. Zinc and selenium are also important,” she says. “Be aware that iron deficiency has an immune-suppressive effect, too. Good sources include red meat, fish and liver, beans and pulses.”
‘Being physically active mobilizes the immune cells, which otherwise are just sitting around in organs and blood vessels,” explains immunologist Professor Arne Akbar. According to a study of 1,000 people, those who were most active (doing five sessions of aerobic exercise a week) cut the number of days they suffered with a cold by almost half.
Get enough sleep
Lack of sleep can put you at greater risk of catching a bug. A study monitored the sleeping habits of 150 adults for two weeks before exposing them to a cold virus. Those who slept less than seven hours a night were three times more likely to subsequently catch a cold than the rest.
Find the sun
Vitamin D plays a vital part in activating the body’s T-cells, which destroy invading bugs, and help keep our immune system in check. We get 90 per cent of our vitamin D from sunlight, however a quarter of us are deficient come spring. When the sun is shining, expose your hands, arms and face for a quarter of the time it would take to burn, before applying sunscreen. Some experts recommend a vitamin D supplement during winter.
Deal with stress
Chronic stress can leave the immune system strained, with raised levels of the stress hormones cortisol and noradrenaline making us more susceptible to infections. If long-term stress is affecting your wellbeing, mindfulness meditation, laughing and an optimistic approach can help.
Nurture your gut
There are trillions of bacteria in our gut that help to digest food, and compete with harmful microbes for nutrients and space. They also release antimicrobial compounds and communicate with the immune system in ways that researchers are continually investigating. Antibiotics strip the gut of good bacteria, so if you have to take them, try supplementing with a probiotic to boost the number of good guys, too.