As we tentatively emerge from the COVID-19 lockdown, many of us are wondering how we can protect ourselves, our families and our community from a second wave of coronavirus infections.
The COVID-19 pandemic "represents the greatest health crisis of the last hundred years," Dr Michael Mosley writes in his new book, COVID-19: What you need to know about the coronavirus and the race for the vaccine.
SARS-CoV-2 – the name of the virus that has sent the world into shutdown in 2020 – is a cunning enemy, he writes. "It's a killer with a range of impressive superpowers, including the ability to travel amongst us, undetected, infect almost everyone it meets and then reproduce liberally, before jumping off in search of a new host."
Viruses spread via droplets of fluid. "A single cough can produce around 3,000 droplets…and release around 200,000,000 (2 hundred million) virus particles into the air," writes Dr Mosley. Heavy droplets generally do not travel further than two metres but small droplets, known as aerosols, can remain suspended in the air, like smoke, for up to three hours.
Two of our most effective weapons against the virus are physical distancing and using water and soap, which breaks down the fatty outer membrane that surrounds the short strand of COVID-19 RNA.
Until scientists develop a vaccine, Dr Mosley recommends avoiding indoor spaces with poor ventilation as much as possible. "Outdoors it dies very, very fast indeed because its genetic material is fragile and ultraviolet light is very good at killing it," he tells SBS Food.
COVID-19, the immune system and your diet
A robust immune system is "absolutely vital" in protecting us from COVID-19, Dr Mosley says. "People who are most at risk are people over the age of 60 and people who have pre-existing conditions."
People with heart disease, type 2 diabetes, high blood pressure or who are obese tend to have weaker immune systems, which puts them at increased risk of the coronavirus. Many COVID-19 victims succumb to a cytokine storm when the immune system overreacts and starts killing healthy tissue as well as the virus.
The good news is that it's possible to strengthen a weak and inefficient immune system by making sure you get enough sleep, exercise often, manage stress, and eat a diet that supports immune function.
"I'm a big fan of the Mediterranean-style diet because it gives you a broad spectrum of nutrients," says Dr Mosley. There is substantial scientific evidence, he writes in his book, that adopting the Mediterranean diet will cut your risk of heart disease, cancer, type 2 diabetes, depression and dementia.
"I'm a big fan of the Mediterranean-style diet because it gives you a broad spectrum of nutrients."
Some vitamins and minerals play vital roles in the body's immune system, such as Vitamins A, B, C, and D, as well as iron and selenium. "If you want to keep your selenium levels up, then a handful of Brazil nuts a couple of times a week will do it," Dr Mosley says.
Another rich source of selenium is oily fish, which also contains omega-3s and is "very good at calming down the immune system," says Dr Mosley. Oily fish, like seaweed and olive oil, also helps reduce chronic inflammation, which means you are less likely to experience a cytokine storm if infected with COVID-19.
Your microbiome – the vast colonies of bacteria that populate your digestive system – also plays a critical role in immune function. Good bacteria in the gut produces anti-inflammatory substances that "calm down your immune system and stop it going too crazy," Dr Mosley says.
You can enrich your microbiome by eating probiotic foods, like sauerkraut and kimchi, and fibre-rich prebiotics foods. It's also important to avoid highly processed food, says Dr Mosley, who has a rule "to never eat food you can buy in a petrol station."
Emulsifiers, commonly found in factory-made food to extend shelf-life, "are bad for the microbiome," he says. "If you're eating a lot of junk food, then you get these pro-inflammatory microbes in your gut that produce inflammation."
Michael Mosley's tips for eating to support your immune system
Eat healthy fats found in olive oil, avocado, salmon, tuna, full-fat dairy, nuts and seeds.
- Eat plenty of protein, particularly as you age, such as seafood (particularly oily fish), chicken, some red meat, eggs, tofu, beans, pulses, dairy, nuts and seeds. Avoid processed meats like salami and bacon.
- Eat colourful vegetables, especially the green leafy variety, and swap refined carbohydrates for wholegrains.
- Don't snack between meals.
- Drink water, tea, black coffee, and the occasional glass of red wine.
- Eat fermented foods like sauerkraut and kimchi.
- Get plenty of fresh air and sunshine for Vitamin D.
Love the story? Follow the author here: Twitter @nicoheath