Most of us know the basic ideas on how to live a healthy life; eat well, get plenty of sleep and make sure to move your body.
Dr Roderick Mulgan has been a medical professional for more than 30 years and believes the quality of our health particularly as we age is very much down to what we eat.
He's written a new book, Eat Yourself Healthy, where he sifts through the science of healthy living
The foundation of good living is eating a diverse and largely plant-based diet, he told Summer Times.
Photo: 123rf
“We've known that for a long time, all the communities around the world where people live a long time, all live in that way.
“And diversity needs to be emphasised, it's not enough to have three veg for dinner. You should have six, you should have nuts, you should have legumes, you should be heavy-handed with spices and herbs. They're all part of it. Tea and coffee are part of it. It's the diversity of food that is really the foundation for living well for a long time.”
Sleep is now better understood than it’s ever been, he says.
“One of the key things about sleep is that it's got rhythms, sleep isn't one thing, go unconscious, and then come out of it in the morning. and off you go.
“You have different layers of sleep. So, you have light sleep and deep sleep and what's called REM sleep, which is when you're dreaming.
“And the crucial thing is to make sure you get the deeper layers. “
One of the chapters in his book examines a theme called he calls “hidden hunger”.
“Good food, even healthy food, isn't what it used to be. All our food, apart from seafood, comes from topsoil.
“And that includes meat, of course, because the animals eat grass. And we've been using the same fields and paddocks for a very long time.
“I mean, in the northern hemisphere, they've been cropping the same fields for centuries.”
Certain minerals we need have become depleted in agricultural land, he says.
“And there are things we need, like iron and zinc and selenium. And the field only has so much.
“Every time a crop is taken, there's less for next time. So, the micronutrients of modern plant food are quite significantly less than they were 50 years ago.”
Data supports this, he says.
“You need 10 tomatoes, to get the copper intake of one tomato in the 1940s.”
The solution is to ramp up the diversity of diet, he says.
“If you need 10 tomatoes for the micronutrient richness of one tomato, make sure you eat lots of them.
“Not literally 10, but the point is that it emphasises the importance of a rich array of plant food every day. If it's not as nutritionally rich as it used to be, then we need as much of it as we can reasonably consume.”
The complexity of the gut is also much better understood now, he says.
“We've known for decades that our bowels have bacteria in them, and they help with digesting fibre.
“And they make certain vitamins like vitamin K. And that's what they did. And it's fairly boring, and don't worry about it.
“And then about 20 years ago, at the start of the century, gene sequencing technology was developed.”
This technological breakthrough revealed the extraordinary diversity of microorganisms in the bowel, he says.
“It's a total rain forest, in your bowel, if your bowel is healthy.”
These bacteria have their own genes which make bioactive molecules inside the body, he says.
“These bioactive molecules float off into your bloodstream, and they manipulate your metabolism. So, the genes that are driving you, they're not all yours.
“And the micro-organisms in your bowel have about 100 times the diversity of genes of you. So, you're being hacked.”
This new-found knowledge has profound implications, he says.
“It does seem to have a lot to do with brain health, things like depression, things like Parkinson's disease are all being probed to see if bowel bugs have got something to do with this.
“And the other thing that seems to be important is body weight. If you take the bacteria from the bowels of obese mice, and gives them to thin mice, the thin mice get fatter.”
Keeping a healthy gut comes down, again, to the principle of diversity, he says.
“The key point is that you've got to look after your internal garden. That's the issue. Your internal garden has an awful lot to do with whether you're healthy, whether your immune system works, whether your brain works properly, how long you live, your body weight, that sort of thing.
“The key point is that when you eat something, you're not the only thing eating it. Everything you eat, feeds your gut.”
And what the gut likes most is fibre, he says.
“Epidemiologists have known for a very long time that people who eat fibre tend to be healthy. But it's never really been obvious why, because we don't tend to absorb fibre, fibre has very long molecules. And they don't tend to nurture us; well here is the is the answer. They nurture the bacteria.”
