So what can we do to protect ourselves against Covid, or improve our protection against severe illness?
Lose weight
If you’re overweight, it’s a good idea to try to reach a healthy weight. Except for getting vaccinated, it’s perhaps the most important thing you can do to support your immune system.
The issue, explains Danny Altmann, professor of medicine and immunology at Imperial College London, is that obese people have a “somewhat dysfunctional immunity”. He says scientists are starting to see fatty tissue (adipose tissue) “almost as a distinctive organ in the body, with different properties and different inflammation”.
A major factor is inflammation, the redness and swelling found in your skin or tissue when it gets infected. It’s a natural protective response deployed by the immune system to fight an incoming virus (the swelling helps to isolate the foreign substance from contact with organs and body tissue). But it’s not always helpful; sometimes inflammation can ‘go too far’, causing serious problems. Indeed, an overly vigorous immune response to Covid, characterised by inflammation and swelling on the lungs, is the factor that ultimately ends up killing many Covid patients.
And research shows that obese people are far more likely to have an inflammatory immune response than non-obese people. “You can certainly hypothesise how, for quite an inflammatory lung disease like Covid, [obesity] can play into your outcome,” says Altmann.
Brush your teeth
A study of 568 Covid patients published earlier this year by researchers at McGill University in Canada found that poor oral health makes you more likely to become severely ill after contracting the virus. Patients who suffered from periodontitis (known commonly as gum disease) were 3.5 times more likely to be admitted to intensive care after testing positive for Covid, 4.5 times more likely to need a ventilator, and 8.8 times more likely to die.
Scientists still aren’t sure exactly why gum disease might have this effect. But experts like Macciochi say it’s a good idea to brush your teeth more regularly if you’re worried about the omicron variant.
Get your five a day
Think of food and drink as the fuel we use to power our body’s immune system, like the armour and weapons you provide to a defence army. Macciochi says it’s important to avoid deficiencies in key vitamins and minerals, and to eat enough protein, the “building blocks of antibodies of immune cells”. She also advises an intake of plenty of healthy fats like omega-3, which “make up the immune cell membranes”; and fibre-rich carbs like wholewheat pasta and wholegrain cereal, which feed our gut microbes.
Other doctors say the best option is a low-carbohydrate, Mediterranean diet rich in fruits and vegetables. The more colours you include on your plate, the more nutrients you will get. This should give you a wide variety of antioxidant and anti-inflammatory phytonutrients – helpful for fighting infection, says Dr Claire Bailey, GP and author of Clever Gut and Blood Sugar Diet.
“Have the fruits and vegetables whole and ideally with the skin on as this contains essential fibre that feeds the healthy bugs in your digestive tract, crucial to fighting infection,” says Dr Bailey.
