Is your DNA your destiny?

Your DNA is important, but it's only a starting point. Knowing which risks you've inherited can guide your health prevention strategies. From there, you can assess your environment and lifestyle and take important steps to protect your health in the future.

Studies of identical twins show just how much external factors work alongside your DNA to shape your health. Identical twins, siblings who share the same genome, often develop the same DNA-related health conditions – but not always. The amount of difference between twins shows the extent to which each condition depends on genetics, and how much it can be influenced by your behavior and environment.

In addition, most common health conditions rarely come down to one gene or SNP. Multiple SNPs or genes working together affect your risk of most common, complex disorders. The particular versions of the markers you've inherited may push your risk up or down slightly.

Your genetic risk can't be changed. But the rest of your risks often can, by what you eat, what you drink, where you live, how you live, how active you are and factors not yet discovered.

In some cases, the environmental risks carry much more weight than the genetic risks. For instance, regardless of your level of genetic risk, your overall risk of type 2 diabetes can be reduced substantially by keeping your weight under control. What's more, getting a comprehensive view of your risk for many conditions allows you to tailor your preventive health strategies accordingly: If you are at increased risk for both a heart attack and osteoarthritis, regular exercise will benefit your heart. But with your arthritis risk in mind, you'll also know to keep that exercise low-impact. And even if a condition is not preventable, knowing from a genetic test that you're at risk allows you to pay closer attention to its warning signs, detect it earlier and possibly lessen its effects.