Longer Living Through DNA

Scientists Find 150 DNA Differences that Lead to a Long Life

by Dr. Barry Starr, Stanford University

The Fountain of Youth. The Sorcerer’s Stone. People have been looking forever for ways to live longer. And now scientists may have found a way.

Unfortunately it isn’t something you can buy or even steal. It is something that is hidden away in a few people’s DNA.

In a new study, scientists have found around 150 DNA differences that people who live a long time have in common. These long-lived people don’t necessarily share them all but most of them did need to have a good fraction of them to live past 100.

She may have the right
DNA to live past 100.

In fact, scientists were able to break the long-lived people in their study into 19 separate groups. These groups tended to both share the same subset of DNA differences and to come down with the same age-related diseases around the same time.

What all of this means is that scientists may now have the means to come up with a genetic test for long life. And one for predicting which age-related diseases someone will get when.

But like lots of genetic tests, these won’t work for everyone. There are some people who will live to be 100 who don’t have any of these DNA differences (this study even found a few of these folks). There’s apparently more than one way to keep Death at bay!

If these results hold up, then they might even be useful for the majority of people without these differences. No one is going to be able to engineer these differences into their DNA anytime soon. But knowing about them will eventually allow scientists to understand why these folks live longer.

Once they’ve figured that out, they may be able to design medicines that can mimic what the DNA differences do. Then we’ll finally have our Fountain of Youth. In pill form anyway.

Learning about Aging and Disease

Scientists still don't know exactly why people age. They have theories of course but no real answers yet. This kind of study can help scientists figure it out.

For example, one DNA difference scientists found in this study was in a gene that deals with chromosome stability. Remember chromosomes are how DNA is stored. And DNA has the instructions for making and running a person.

One theory on aging is that over time, DNA builds up mistakes. Eventually there are enough mistakes that the cell can't work right anymore. The end result is getting old.

People with the DNA difference in the chromosome stability gene might have more stable chromosomes. In other words, their DNA might be less likely to build up mutations and so they would age more slowly.

Scientists knew about this sort of thing before. But the researchers in this study discovered over 100 other differences they can investigate. So they will undoubtedly learn at least something new about getting old.

In fact they found some differences that might confirm another theory on aging. When scientists have looked at people over 100, one attribute that sticks out is that these folks tend not to suffer from age-related diseases until much later in life.

The mouse on the right
has a DNA difference
that causes DNA damage
to build up which
makes it age faster.

So the idea is that some people age more slowly because they don't get sick until later. Becoming ill puts people on the path towards the end of life.

At least five of the DNA differences found in this study relate to known diseases like dementia, high blood pressure and heart problems. And the people with these “good” DNA differences got these diseases later and lived longer. If this is true in lots of people’s DNA, then scientists will definitely be on a path to better understand aging.

Not only that, but they may also learn a lot about age related diseases too. By understanding the DNA differences associated with disease, scientists will also learn about the diseases. And maybe use what they learn to design medicines to treat those diseases.

The Fountain of Youth

The ultimate goal of studies like this is to find out how aging works and from that, learn how to slow it down. This will take awhile but eventually what scientists figure out may be used to help people not fortunate enough to have inherited the right DNA from their parents.

One way this might work goes something like this. Someone will go to the doctor and get a genetic test. The test will reveal which of the 150 differences that person has.

By then scientists will have investigated these differences enough so that they have come up with medicines that mimic what these DNA differences do. The patient will be given medicines for the DNA differences he or she doesn’t have. The end result will be a longer life.

This is obviously in the future but it will probably happen one day. Then everyone can live a longer, healthier life no matter what is in their DNA.

More Information

A Study that Worked!

An amazing part of this study is that it worked at all. Scientists have been having a terrible time figuring out complicated diseases like obesity, heart disease, etc. The genetic tests just don’t seem to find much that is significant.

This study is different though…it found lots of differences that together had big effects. Why did this study work when others failed?

Unlike most genome wide
association studies (GWAS),
this one had significant results.

One possibility is that these scientists looked for lots of differences all at once. Usually scientists look for a few key ones that have a big effect. But complicated diseases may involve lots of genes, each having a small effect. So if scientists look for only big effects from a small set of differences, then their tests come up empty.

Here they looked for patterns of DNA differences that affected aging. In other words, they concentrated on looking for lots of little effects that together have a big effect. If they had done their study the more traditional way, they might not have found anything.

The other thing these scientists did was to include a lot of families in their studies. This has plusses and minuses.

On the plus side, using families makes finding important DNA differences easier. Any two people have, on average, 6 million differences in their DNA. These scientists found 150 or so involved in aging which means about 6 million differences didn’t matter.

People in families have more DNA in common which means there are fewer differences to sift through. In other words, scientists need to find a needle in a much smaller haystack.

On the minus side, families sometimes share DNA differences that other people don’t have. What this means is that scientists are sometimes fooled into thinking they’ve found something common when they have only found something important in a single or extended family.

Scientists may be able to apply these lessons to future studies. Then they may finally find significant DNA differences or patterns that predict illness. And maybe use the results to come up with cures for all sorts of genetic illnesses. Not bad for one study.

More Information

Content provided by the Department of Genetics, Stanford University.