Winter is coming and a second wave of Covid-19 is already with us, so it has never been more important to strengthen your immunity.
Along with hand-washing, masks and social distancing, it’s the best defence we have against the coronavirus.
A vaccine is still some way off and scientists warn that without one there is no hope of achieving the herd immunity needed to end the pandemic.
Boosting your own immunity makes sense, and studies show there is lots you can do.
A balanced diet is key, but there are certain nutrients that are particularly important – and scientists have been working hard to find the stars that can help in the Covid battle.
Take these simple steps to strengthen your immune system and keep you well through the tough winter ahead:
Vitamin D, which is essential for healthy bones and muscles, is often known as the sunshine vitamin – giving a big clue as to why we don’t get enough in winter.
While it can be found in some foods, including oily fish, red meat and eggs, our bodies grab the majority of what they need from exposure to sunlight.
One in five Brits is deficient, with the number increasing as the nights draw in.
And that’s why the official advice is to consider taking a supplement containing 10mcg of vitamin D
(the equivalent of 400IU) during winter.
But as well as keeping bones strong, this simple vitamin could also play a key role in the fight against Covid-19.
A super-study published earlier this year, which analysed results from 39 trials, found that taking 10mcg of the sunshine vitamin reduced the risk of respiratory infections by up to 23 per cent.
More recently, researchers at the University of Birmingham, who tested blood samples from 392 healthcare staff, found that 72per cent of those who were deficient in vitamin D had also caught Covid-19.
By contrast, only 51 per cent of those with good levels carried antibodies confirming they had been infected.
Covidence-UK, a study that uses monthly surveys of UK citizens to identify potential risk factors for Covid-19, has also identified a link.
Researchers are launching a randomised control trial to see if providing free vitamin D to people with low levels reduces their odds of catching the virus. To sign up and support the Covidence-UK search for ways to reduce the risk of Covid-19, visit qmul.ac.uk/covidence.
Some scientists believe it’s no accident that countries where cabbage and fermented vegetables, such as sauerkraut and kimchi, are popular, have reported lower coronavirus death rates.
Dr Jean Bousquet, Honorary Professor of Pulmonary Medicine at Montpellier University, France, has calculated that every gram of fermented vegetables eaten each day reduces the risk of dying of Covid-19 by 35 per cent.
A similar pattern was seen in countries where a lot of cabbage is consumed, and Professor Bousquet believes the benefits are down to high levels of the antioxidant sulforaphane in them.
He adds: “Nutrition may play a role in the immune defence against Covid and may explain some of the differences seen in Covid across Europe. I’ve now changed my diet, and it includes raw cabbage three times a week, sauerkraut once a week and pickled vegetables.”
Dozens of studies have underlined the importance of zinc for strong immunity. And the World Health Organisation confirms it, saying: “Zinc is thought to help decrease susceptibility to acute lower respiratory tract infections by regulating various immune functions.”
Zinc can be found in shellfish, beans and lentils, but eight per cent of adults here in the UK do not get the recommended intake.
Research has shown that taking zinc within 24 hours of cold symptoms appearing cuts the duration of infections by a third.
Excitingly, studies have confirmed zinc inhibits Covid-19 – and there is evidence it may boost levels of interferon, a protein that helps our immune system identify threats.
The balance of good and bad bacteria in our gut has a big impact on immunity. Dr Bousquet’s research has also identified a link between fermented dairy products, such as yoghurt and kefir, and a lower rate of deaths from the virus.
A recent Chinese study discovered that probiotic drinks that contained a combination of lactobacillus bacteria reduced the risk of respiratory infections by 59 per cent.
Another study, published in the European Journal of Public Health, found that children who were given daily probiotic supplements werearound a third less likely to needantibiotics.
A 150ml glass of orange juice provides more than 80 per cent of the immune-strengthening vitamin C that we need each day.
But there is growing scientific interest around another nutrient in orange juice, which could be even more important for our immunity.
Hesperidin, a micronutrient found in citrus fruit, slows the rate that viruses can replicate. Laboratory tests showed such strong antiviral activity that some scientists think it could be used to develop new drugs against dreaded influenza.
A recent study showed it locks on to key proteins on the Covid-19 virus, which could make it harder for infection to take hold.
Because the highest concentrations are found in the pith of fruit, juice will have more hesperidin in it than whole fruit. Shop-bought orange juice contains three times more hesperidin than juice squeezed at home.