Professor Phil Hansbro. Photo: Centenary UTS Centre for Inflammation / supplied
Just a few days of eating healthy could be all it takes to ease the effects of chronic inflammation, according to the author of a new book about diets good for your gut.
But only as long as you stick to it.
Professor Phil Hansbro, deputy director of Australia's Centenary Research Institute and director of the Centre for Inflammation at Sydney's University of Technology, is behind new book The Good Gut Anti-Inflammatory Diet.
"We have a lot of inflammation," he told RNZ's Sunday Morning. "We eat a lot of processed food that's somewhat inflammatory, we're exposed to air pollution a lot, and that's inflammatory as well."
Inflammation is part of the body's immune response, but can become a problem if it doesn't stop when it's meant to. Chronic inflammation has been linked to all kind of conditions, including heart disease, arthritis, Crohn's disease. asthma, emphysema and diabetes.
"There's emerging links now with many different cancers and inflammation," said Hansbro.
"If we can have a good health diet that keeps up having a good healthy microbiome, then we control the inflammation" - Professor Phil Hansbro
And Long Covid too.
"You've got underlying inflammation occurring for long periods in the lungs, that keeps the disease and the symptoms going. Inflammation goes all over our body - it's transported around the bloodstream and the lymph system.
"So if you have any other conditions when you have Covid, then often a lot of them flare up because they're underpinned by the same sort of inflammatory cycles."
Hansbro said when a patient goes to see a GP with inflammation in one part of the body, that's often what the doctor will focus on - but he says research is now suggesting inflammation should be treated as an all-of-body issue, starting with our diets.
"If we can have a good health diet that keeps up having a good healthy microbiome, then we control the inflammation. We don't want it to shut down completely, because we want to still be protected against infections; but we want it controlled, so it's not damaging."
There are trillions of bacteria in our guts, good and bad, each requiring different kinds of nutrients to survive and flourish. Just eating probiotic yoghurts and the like is not enough.
"As well has having the probiotic things, you also need to feed them the foods that they need to grow and produce the anti-inflammatory factors that they produce to stop us getting inflammatory diseases… if you have a bad diet for a certain period of time, then that's growing to grow out a particular cohort of bacteria and they're going to outcompete those who are not being fed, so then you will lose those bacteria.
"If these are a beneficial bacteria and you've lost them, then that could be a long-term thing if you don't regain them once you start taking in a better diet."
While it is not a magic bullet, eating a better diet - and not too much - can help significantly.
Eating a high-fat meal, for instance, can result in a noticeable increase in inflammatory cells in one's lungs just four hours later, he said; while dining on foods high in fibre, broccoli, red fruit, and even treats like dark chocolate can "modify your gut microbiome in a few days" for the better.
"The longer that you're on it, the better it is."
But even Hansbro, who has been researching it for decades, admits he does not always get it right.
"You don't need to be a saint in order to have a reasonable diet. I have to say though, since I have been working on this my diet has improved significantly."