If this winter has felt like a grim battle against illness, from fevers and aches to hacking coughs and snotty noses, you’re not alone. It’s all thanks to the “tripledemic”, so called because of the outbreaks of Covid and flu and tenacious colds caused by RSV (respiratory syncytial virus), all at the same time – not to mention the sharp rise in norovirus cases in recent days.
Back-to-back lurgies, sick days and sniffles can make anyone feel helpless. But fortunately we can all make changes to our lives that will give our bodies a fighting chance against even a barrage of bugs.
“Our immune system is pretty good,” says immunologist Sheena Cruickshank, professor in biomedical sciences and public engagement at the University of Manchester. “But the modern lifestyle will negatively affect it: a poor diet, being sedentary, having a high-stress job or being sleep deprived will all impact your immune system.”
Follow these steps to improve your immunity – and boost your mind and body in the process.
Get jabbed
With a particularly vicious flu bug circulating, which has led to a two thirds increase in hospital flu admissions this winter, don’t delay getting jabbed. The over-50s, pregnant women, carers, people with weakened immune systems and children can have the vaccination free on the NHS. For those not eligible, Boots and other high street pharmacies provide flu jabs for as little as £9.95.
And are you up to date with your Covid boosters? “Recent studies showed a drastic reduction in transmission from people who’ve been vaccinated against Covid,” says Cruickshank.
Being vaccinated against flu and Covid may also provide added protection against strep A, the common bacteria behind scarlet fever, that has caused terrifying illness and even death in children over the past few months.
“Strep A is part of a group of bacteria that are sometimes called opportunistic infections,” says Cruickshank. “They’re often already in our bodies, where they’re held at bay by our immune systems, but when you get damage to your lungs from a nasty viral infection like RSV or flu, for instance, they find a way in.
“We see cases of strep A every year but the recent increase might be because we’ve had a larger wave of viral infection this winter so there have potentially been more opportunities for strep A to take hold.”
Slash the salt
We all know processed food isn’t good for our hearts, but now experts say that a diet high in sugar, salt and saturated fats is bad for our immune defences, too.
In the UK, adults consume 8.4g of salt a day (the recommended daily amount is 6g), but according to German researchers excessive salt intake weakens the immune system by inhibiting our bacteria-attacking immune cells. In the 2020 University of Bonn study, volunteers who ate an extra 6g of salt a day (equivalent to two fast-food meals) showed immune deficiencies after just one week.
So how can you ensure you’re eating the right balance of minerals, vitamins and fibre to support the immune system and boost “good” gut bacteria?
Try following this formula from immunologist Dr Jenna Macciochi, author of Your Blueprint for Strong Immunity, at each meal: a palmful of protein; a finger of healthy poly- or mono-unsaturated fats; a fistful of carbohydrates such as wholegrains and legumes; and two palms’ worth of fruit and vegetables, including leafy and sulphur-rich greens, such as rocket, kale, cauliflower, broccoli, onions, garlic and leeks).
Meditate
Tibetan monks who meditate for two hours a day aren’t just calm and spiritually in tune, their guts are also packed with immune-regulating friendly flora, according to a new study.
Chinese researchers compared the blood and stool samples of 37 Tibetan Buddhist monks with those from 19 residents in neighbouring areas. Both groups ate the same staple foods of barley, rice, steamed bread and noodles, vegetables, meat and butter tea.
But the meditating monks had significantly more beneficial bugs in their guts: 42 per cent of their microbiome was made up of “good” prevotella bacteria, compared with only six per cent for the control group, while 29 per cent was the beneficial bacteroidetes bacteria, compared with four per cent in the other group.
Get the right kind of stress
It may seem like a fad, but the smug cold-water swimmers filling up your Instagram feed might be on to something. A 2018 study found that ending your morning shower with a blast of cold water could lead to fewer sick days than taking a conventional hot shower.
It’s thought that the shock of being doused by frigid H2O gives the body a short dose of stress, which helps the immune system tune itself up. This is a process called “hormesis”, which “describes the health benefits of being continuously challenged or ‘what doesn’t kill you makes you stronger’,” says Dr Macciochi.
In addition, cold water benefits our circulation and lymphatic system and can improve resilience to inflammation, she says.
But while periods of controlled stress can have a beneficial effect on the immune system, chronic stress has the opposite effect. “We make lots of hormones when we’re stressed, and when we’re stressed we get bugs,” says Cruickshank.
The stress hormone cortisol impacts the way the lymphocytes (a type of white blood cell) function, making them less able to deal with infection. That is why when we’re under duress we can suffer from cold sores or have an attack of shingles from decades-old infections.
“The viruses that cause chicken pox and cold sores sit there in our bodies for years but when we get run down our immune surveillance, which keeps them in check, isn’t keeping up that pressure any more and they flare up,” she explains. “The varicella-zoster virus, which causes chicken pox, flares up as shingles and the herpes virus causes cold sores.”
Take the stairs, not the lift
Exercise doesn’t just give your heart and muscles a boost, it’s also a workout for your immune system. “Moderate exercise is associated with enhanced mobilisation and function of your immune cells and lower risk of upper respiratory tract infections,” says Cruickshank.
The NHS advises we do at least 150 minutes of exercise a week spread over four to five days a week.
“It’s not about running marathons, it’s an achievable level of activity, like taking the stairs at work rather than taking the lift, or trying to reach 10,000 steps a day,” she says.
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Dose up on the sunshine vitamin
In the dark winter months, a daily dose of vitamin D could help keep colds and chest infections away. Dubbed the “sunshine vitamin”, because we make it by exposing our skin to the summer sun, vitamin D is crucial for bone health.
But there is increasing evidence that it plays a key role in the immune system. “Some studies have suggested that low vitamin D levels give you a higher susceptibility to upper respiratory tract infection,” says Cruickshank. “And some studies have linked low vitamin D to other defects in the immune response.”
The NHS advises that everyone take 400iu of vitamin D a day between October and March.
Get an early night
Lack of sleep could literally make you ill, according to US researchers. In a small 2017 study of twins with different sleep patterns, the twin who slept less had a worse immune system than their sibling.
“The immune system functions best when it gets enough sleep. Seven or more hours of sleep is recommended for optimal health,” said lead author Dr. Nathaniel Watson, co-director of Seattle’s UW Medicine Sleep Center.
And having a consistent sleep pattern and respecting our circadian rhythms could also contribute to good health. “All of our cells have biological clocks and we know our immune system has these biological cues,” says Cruickshank. “If our body clock gets out of kilter it can impair immune response.”
Thankfully, a decent kip is one of nature’s best medicines: a 2019 a study in the Journal of Experimental Medicine found that a good night’s sleep can increase the function of white blood cells that kill invading bacteria and viruses.
