By Jordyn Cornier From Care2

Home genetic test kits like 23&Me are pretty incredible. With one little vial of saliva, you can find out your genetic predisposition for diseases like cancer, Alzheimer’s, obesity and more—which potentially allows you to make lifestyle shifts and take precautions to turn those genes off. But researchers have started wondering—is it better to know your genes, or do they become something of a self-fulfilling prophecy?

Psychologists at Stanford University decided to find out. They recruited 223 volunteers and told them that they would be helping them create personalized fitness and diet programs based on the volunteers’ genetic predispositions. They tested some patients’ aerobic fitness on a treadmill, while others had their blood drawn after drinking a caloric shake. Then, they collected saliva for genetic testing.

In the next session, participants received the results of this genetic testing—all of which were made up and distributed randomly.

What happened next was incredible. The volunteers had their fitness and hunger tested again, now knowing the fake DNA test results. Not only did the people who were told they had the worse exercise gene quit running sooner than they had previously, but the oxygen uptake of their lungs was actually hindered on a biological level.

Once participants thought that they were genetically predisposed to be worse at aerobic activities, their bodies actually acted like they were worse at aerobic activities on a cellular level.

Those who thought their genetic tests proved a predisposition for hunger not only reported feeling hungrier after drinking the shake a second time, but there were higher levels of hunger hormones in their blood than before they got their made-up results. Their bodies actually were hungrier—it wasn’t all in their heads.

This means that what we believe to be true actually affects our bodily functions on a biological level. Genes or not, our belief systems affect our health.

So, before you get your genes tested, carefully weigh the potential downsides. While knowing your risks is great, you can never unknow them. We’ve known for a long time that our genes are malleable—that genetic tests aren’t necessarily a sentencing—but this new study raises concerns.

When we know that our genes are programmed to behave a certain way, the simple act of taking that to heart could cause those genetic expressions to become true. It may seem a little wild, but our beliefs and thoughts hold more power than we give them credit for.

For more on this story go to: https://www.care2.com/greenliving/the-downside-of-home-genetic-testing.html