Gut-friendly food to boost immunity
Dr Michael Mosley tells Maria Lally why feeding your ‘good’ bacteria during a pandemic is just what the doctor ordered
According to Dr Michael Mosley, creator of the 5:2 Diet, the recent outbreak of coronavirus has shown us just how vulnerable we are to the emergence of new infectious diseases. “The spread of this novel virus is a particular problem because currently we have no reliable drugs to combat it and no vaccine,” he says, “so currently one of our best forms of defence, alongside following government advice on social distancing and hand washing, is a fully active immune system.
“Your immune system is a complex army of cells,” says Dr Mosley, “which are there to identify and destroy any potentially dangerous invaders. But to do this effectively, the army needs to be in the best possible condition for combat.
“As we get older our immune system tends to get weaker and less effective, but there are things we can all do to keep ours in good shape and ready to take on all comers.
“One way is to bolster your microbiome, the microbes that live in your gut. They are central to our health, our mood, better sleep, allergy prevention, and importantly at the moment, immunity. Along with the gut’s ability to help manage a healthy weight, it’s clear that for long-term health, we need to start from the inside.”
The microbiome is a community of trillions of bacteria, viruses, fungi and other microbes that live mainly in the large intestine or colon. Our personal microbiome is shaped by our genetics, but it is also strongly affected by what we eat, how we exercise and how we live day-to-day.
“As we get older, having lots of ‘good’ bacteria living in our gut is increasingly important because they help us fight infection and prevent the onset of diseases like type-2 diabetes,” says Dr Mosley. “One of the best ways to improve the ‘good’ microbes that live in our guts is through eating a Mediterranean diet because the high fibre content is a great way to supercharge your microbiome. The diet is widely seen as the healthiest, most nutrient-rich on the planet, and contains lots of vegetables, fruit,
‘It’s clear that for long-term health, we need to start from the inside’
whole grains, lentils, beans, nuts, seeds, spices and olive oil, as well as some oily fish, cheese and full-fat yogurt.
“Other foods which are beneficial for our microbiome, and therefore immunity, include live yogurt, cheese, sauerkraut or kimchi, and sourdough bread.”
These probiotic rich foods are also rich in vitamin c, iron and zinc, which are known to boost the immune system. Green tea, mushrooms, garlic and vitamin C-containing foods like citrus fruits are also beneficial.
“It’s also important to try to avoid (or at least cut down) on processed foods, like takeaways and ready meals, as tempting as they may be during self-isolation, as these encourage the growth of unhealthy bacteria in the digestive system.
“Treat your microbiome with care; feed it well and it will look after you. Eating lots of sugary or processed foods, on the other hand, will just reinforce and feed the ‘bad’ microbes that also live down there.”
Dr Mosley also points out there is a proven link between gut health and depression, and the brain’s capacity to cope with stress. “And at times like these, we need all the help we can get. Studies show that having a healthy microbiome can have a positive impact on our mood.
“First, food containing lots of fibre can help your mood because the ‘good’ bacteria in the microbiome are adept at turning fibre into chemicals called short chain fatty acids, which are anti-inflammatory compounds. These travel through the blood and reduce inflammation throughout the body, including the brain. And inflammation is a major cause of depression.
“Secondly, two to three kilos of microbes live in the digestive system, and, among other things, they produce neurotransmitters, which can travel in our blood to our brains, impacting our mood and anxiety levels. Eighty per cent of our serotonin (our happy hormone) is produced in the gut, so the healthier the gut the more emotionally resilient we tend be.
“Lastly, there’s also evidence that switching to a gut-friendly, Mediterranean diet leads to longer and deeper sleep, which will also improve your body’s ability to fight infection.”