NEW YORK – If you learned your DNA made you more susceptible to getting a disease, wouldn’t you work to stay healthy?
You’d quit smoking, eat better, ramp up your exercise, or do whatever else it took to improve your odds of avoiding maladies like obesity, diabetes, heart disease or cancer, right?
The scientific evidence says: Don’t bet on it.
DNA testing for disease risk has recently expanded in the U.S. The company 23andMe recently started selling the nation’s first approved direct-to-consumer DNA tests that evaluate the buyer’s genetic risk for certain disease or conditions. That go-ahead came in April, about three years after it was told to stop selling such kits until it got the OK from regulators.
The field also gained a new entrant in July, when a company called Helix launched an online marketplace for DNA tests, including some for genetic health risk. Helix decodes a consumer’s DNA and passes the results along to another company for analysis. A request for the currently available health tests must be approved by a physician’s group that reviews the customer’s medical history.
DNA tests for diseases typically assess genetic predisposition to getting sick. They don’t provide absolute predictions about whether or not a disease will strike. Genetic risk is only part of a person’s overall risk, which includes influence from other things like a person’s lifestyle.
While some disease are caused by a single malfunctioning gene, more common illnesses are influenced by multiple genes, and often each gene nudges a person’s risk only slightly.
A 23andMe test that includes ancestry and other information goes for $199. Helix’s decoding costs $80, while the currently available health-risk analyses cost $150 and $125. Both companies use a saliva sample for the test.
Last year, researchers published an analysis that combined 18 studies of people who got doctor-ordered DNA test results about disease risks. None involved direct-to-consumer tests;…