Environmental Influence

Does meditation have the potential to alter the gene structure, especially in case of any damage? Similarly, does walking (or other aerobics) change the gene structure in any way?

-A curious adult from California

February 21, 2008

That's a great question! Activities like meditation and exercises like walking are definitely good for us. They help us deal with stress and build up our muscles, and that helps us stay healthy. But can they affect our DNA? Can the activities we do affect the structure of our genes?

We do know that the things we do have the potential to affect our DNA in specific ways. In fact, a recent study has shown that exercising can make your DNA look younger.

So, the answer is yes, both meditation and exercise have the potential to affect how your genes work. But probably not in the way you are thinking.

Remember that genes are instructions for making a specific protein. They are written out in a DNA code made up of four letters--A, C, G and T. Different genes make different proteins. And all these different proteins work together to make you.

Every cell has the exact same DNA as every other cell. In other words, they all have the same basic set of instructions for all the different genes. So why aren't all cells the same?

Well, cells only read the set of instructions that make them the type of cell they are supposed to be. A muscle cell reads the set of instructions to make it a muscle cell. A brain cell reads the set of instructions that make it a brain cell. And so on.

Cells can also read genes at different levels to make different amounts of protein. It's like the cell is using a volume control knob. The instructions can be read LOUDLY to make lots of protein or quietly to make less protein. Or, the gene can be put on mute, so it's not being read at all. So, a muscle cell and a brain cell could read some of the same instructions but read them at different volumes.

Activities like meditation or exercise almost certainly don't change the actual instructions in the genes themselves. All the A's, G's, C's, and T's will stay the same. This means the way the protein looks will also stay the same.

Instead, activities like this might be able to change which genes get read. Or how much they are read. Or both.

Obviously our DNA doesn't have a volume knob. So how can what we do adjust the amount a gene gets read? It partly has to do with how our DNA is packaged in our cells.

Each of our cells has over 6 feet of DNA! To fit that into a tiny cell, the DNA has to be twisted and compacted and twisted some more into a tiny tangled ball. To be read, a gene has to get free of this tangle so that the cell can see it.

To give you an idea about how this works, grab a rubber band and imagine it is your DNA. Stretch it out and then start twisting it. After a few twists, you get something that looks like a double helix.

Keep twisting the rubber band and soon it starts to twist in on itself. If you keep twisting, you'll end up with a knotted little ball of rubber band. Something like this happens with our DNA too.

A difference between our DNA and the rubber band is that the DNA is twisted around special proteins to help organize things a bit. These DNA-protein coils are called chromatin. Chromatin then makes up the chromosomes that are found inside each of our cells.

So, to fit all that DNA into a tiny cell, DNA twists onto itself to get really compact. But, if your DNA is all twisted up on itself, how can the gene instructions be read to make a protein?

Our cells have other proteins that help open up parts of the coiled DNA so that genes can be read. You can think about it like someone grabbing a small piece of the rubber band and pulling it out of the knot. Our cells also have ways of hiding a piece of DNA that is normally accessible. This would be like pushing a piece of the rubber band deeper into the knot. Now the cell can't get to that gene even though it is still there. (Click here to read more about how cells know what to do at different genes.)

If meditation or exercise does affect our DNA, this is how they would most likely do it. Not by changing the instructions or the chemical makeup of the DNA. Just like stretching or pulling a rubber band doesn't really change the rubber. Instead, these activities might be able to change how those instructions get read by affecting what parts of the DNA are available to a cell to read. (Click here to learn one way DNA can become more or less accessible.)

We don't know for sure that meditation or walking affect genes in specific ways. But we do know that both can affect the brain. For example, exercise can increase brain cells in the part of the brain important for learning and memory. And the areas of the brain involved in attention and sensory processing tend to be thicker in people who meditate.

We may not yet understand how meditation and exercise can bring about these changes in the brain, but it is possible they happen by changing the way genes get read. Even if they don't affect your genes, these habits are a good way to keep your stress low, your body healthy, and your DNA looking younger!

Jennifer Shieh, Stanford University

DNA is twisted so it can all fit in a cell.