We’re used to thinking about ageing as a mixture of our genetic luck and personal lifestyle choices like diet or exercise.
However, a fascinating new study has decided to test a completely different theory, looking at whether uprooting your life and relocating to a different part of the world actually alters how your body functions. It turns out that a massive change in environment does far more than just change your daily routine, and the findings completely challenge what we think we know about how our bodies grow old.
What does ageing really mean?
When scientists talk about ageing, they don’t just mean the number of birthdays you’ve had. They mean what’s happening inside your body. There’s something called your biological age, which is how old your cells and tissues actually look on the inside. Two people who are both 40 years old on their birthday cards could have completely different biological ages, depending on how healthy they are.
Think of it like a car. Two cars might both be 10 years old, but if one was driven gently and kept in a garage while the other was bashed around and left out in the rain, they’ll be in very different conditions. Our bodies work in a similar way. The new study has found that one of the biggest things affecting your biological age isn’t just your genes, but where on the planet you actually live.
How the scientists worked it all out
A team led by scientists from Stanford University in America wanted to find out whether people’s bodies changed when they moved to a different part of the world. They gathered 322 people from all over the globe, including people whose families originally came from Europe, East Asia and South Asia.
What made it really interesting was that some of these people had moved away from where their family was originally from, while others still lived in those areas. The scientists didn’t just look at people’s DNA. They looked at all sorts of things, like the bacteria living in their tummies, the fats in their blood, their immune systems and tiny chemicals called metabolites. It’s a bit like checking every single part of a car’s engine instead of just looking at the bodywork.
Your family heritage still matters a lot.
One of the first big findings was that you can’t just leave your family heritage behind by moving somewhere new. People who shared the same ancestry had loads of things in common with each other, no matter where in the world they actually lived. Their tummy bacteria, their genetics, and even the way their bodies dealt with food all stayed similar to other people from the same background.
For example, people whose families came from South Asia had immune systems that were really good at fighting off lots of different germs. People from East Asia had a special way of processing fats in their bodies. And people of European ancestry had a wider variety of different bacteria living in their tummies than people from the other groups. These differences stuck with them even if they’d moved thousands of miles from where their families came from.
Where you live changes things too.
Even though family heritage was important, the scientists were surprised by how much living in a new place changed people’s bodies. The most amazing finding had to do with biological age. East Asian people living outside East Asia were ageing faster on the inside than East Asian people who still lived back in East Asia.
The opposite was true for European people. Europeans living in North America were actually ageing more slowly than Europeans still living in Europe. That’s a really weird and unexpected discovery because it shows that moving to a new place doesn’t have the same effect on everybody. Some people end up better off and some people end up worse off, depending on who they are and where they go.
Why does this happen?
The scientists think there are loads of reasons your environment can change how you age. Different countries have different foods, different amounts of pollution in the air, different healthcare, different amounts of stress and even different kinds of sunshine. All of these things can affect what’s happening inside you.
One of the biggest things they pointed to was the tiny bacteria living in our tummies, which scientists call the gut microbiome. We’ve all got trillions of these little bugs living inside us, and they help us digest food and stay healthy. When you move to a new country, you start eating different food, and that can change which bacteria live in your tummy.
The scientists found that these gut bacteria were linked to something called sphingolipids, which are special fats that affect tiny caps on the ends of our DNA. Those caps help control how quickly we age. So tummy bacteria can actually nudge how old your body feels on the inside.
Why this is worth thinking about
For a long time, doctors have given the same kind of health advice to everyone, like a one-size-fits-all approach. This study shows that’s not quite right. People with different backgrounds and people living in different places might actually need slightly different advice to stay healthy.
That doesn’t mean some people are better or worse than others at getting older. It just means we’re all built a little bit differently. The same diet that works brilliantly for one person might not work as well for another. The same exercise plan that keeps one person healthy might be less helpful for somebody else. Doctors and scientists are starting to realise that proper health advice needs to take into account both your family background and the place you live.
What does this mean for everyday life?
You can’t really do much about your ancestry, since that’s just where your family came from over hundreds of years. But you can do plenty about the everyday things that affect your environment. What you eat, how much you move around, how clean the air is around you, and how much sleep and rest you get all play a part in how your body ages.
Things like eating lots of fruit and vegetables, exercising regularly, getting enough sleep, drinking plenty of water and looking after your tummy bacteria with healthy foods all help your body stay younger on the inside. The really exciting thing is that scientists are slowly working out how to give us all advice that’s properly tailored to who we are, rather than just guessing. The more they learn about how genes and environment work together, the better we’ll all be able to look after ourselves as we grow up and grow older.
