Scared of what happens when we get old? There are things you can do - even from your 30s onwards - that will affect how you age and how long you'll live, according to research on the new BBC series How To Stay Young.
Angela Rippon and Dr Chris van Tulleken investigated how much of the way we age is down to genetics and how much is lifestyle. Apparently it's around 25% down to genes and 75% is down to how we live.
Here are some of the fascinating things we leaned.
1. There's an easy scientific test that's supposed to reveal whether you'll live a long life.
In the 'sit to rise' test you have to try to sit down on the ground without using your hands, arms or knees, and stand up again in the same way.
To score, start with ten points and lose a point every time you use a hand or knee, or a half point if you wobble. If you score 8-10 you'll lead a long healthy life, 6-7.5 and you've got twice as high a chance of having a shorter life, and so on. But a low score can be improved if you do more physical exercise.
2. After smoking, stress and weight play the biggest role in ageing.
Revolutionary tests on identical twins with totally different lifestyles showed how the way people live makes a huge difference to our biological ages. Dr Chris, 36, who lives a stressful life, found out he was five years older than his chronological age. His identical twin Xand was five years older too, probably due to the fact he used to be overweight.
But Yoga, meditation, exercise and general 'me' time help reduce stress.
3. Eating more high resistance starch can help reduce internal fat.
Angela, 71, had an MRI to show how her organs have aged but found she had a large amount of visceral fat around her heart - four litres more than a healthy person.
High resistance starch is found in pulses like lentils and chick peas or there's a concentrated form that can be added to food. Scientists are developing drugs that can help reduce internal fat but it's largely down to diet and exercise.
4. Not eating meat is one secret to ageing well.
A study on the population of the town of Loma Linda, California (where vegetarianism is very popular) found that for vegans overall mortality is reduced by a quarter compared to meat eaters and they're half as likely to get heart disease.
We met 100-year-old Ellsworth Wareham who was a surgeon until the age of 95. He's been a vegan for 50 years and lives in Loma Linda.
Apparently animal protein stimulates a hormone we all need for growth but as we get older, particularly in middle age, this same hormone speeds up ageing.
You might not have to become a full blown vegan to feel some benefit though, just cutting down the amount of meat we eat can help. And nuts - walnuts especially - can protect us from heart attacks.
5. Building muscle is essential as we age - and dancing is more effective than cardio at the gym.
As we age our muscles degenerate - from our 30s - and as we get older we need to make an extra effort to build muscle mass. A study of two groups over six months found dancing was far more effective than repetitive gym cardio.
6. Having a dog around can help lower stress and therefore blood pressure.
A mental arithmetic test designed to stress people was done a second time but this time with their dogs in the room, and their blood pressure become lower.
7.Scientists are actually developing an anti-ageing drug.
People with conditions like Laron Syndrome - who don't grow at the same rate as other people - could help scientists cure ageing. The drug that's being developed that mimics the effects of Laron Syndrome so one day just popping a pill could stop us developing diseases caused by old age.