Advances in genetic testing are changing lives. Women can now find out if they carry BRCA mutations, which significantly increase their lifetime risk for breast and/or ovarian cancer. And doctors can quickly tell if newborns have certain inherited conditions, allowing them to start potentially life-altering treatments years sooner than in the past. Every day, it seems that scientists are making new, important genetic discoveries that could hold the key to curing disease, making medicines more effective and helping us prevent illness in the first place.
And now, a burgeoning consumer genetic-testing industry is trying to tap into those exciting developments by convincing us we need genetic testing to make our everyday lives better. A growing number of companies is busy marketing direct-to-consumer genetic tests that analyze customers' saliva samples to tell them everything from what kinds of foods they should be eating, to what types of diseases they are most at risk for, to even if they have long-term compatibility with their romantic partner. One of the most prolific direct-to-consumer genetic-testing companies, 23andme, recently made headlines with its announcement that it is directly targeting the Canadian market. (The company has long been accessible to Canadians online, but the move to sell its health-related genetic tests "exclusively" in this country comes a few months after the U.S. Food and Drug Administration ordered the company to stop selling those test kits to consumers south of the border.)
The lure of consumer genetic testing is powerful. Who wouldn't pay a few hundred dollars to mail a spit sample away and find out if he is are going to get Alzheimer's disease, cancer, diabetes or another serious chronic illness? Who wouldn't want to know if she is genetically predisposed to high blood pressure if she eats a salty diet? That kind of invaluable information is surely worth thousands – the couple hundred bucks most companies charge is clearly a bargain.
Well, here's the thing: There is a world of difference between what companies such as 23andme offer and what they are able to deliver. Sure, they can provide you with a detailed report that states which diseases you may be at greater risk of developing, or which medicines you may respond best to if you ever happen to be diagnosed with a condition that necessitates them. Other companies can give you a customized diet tailored to your genetic profile, "empowering" you to finally take the steps you need to live a healthier life.
But here's what they don't say: The claims they make are exaggerated and misleading. There is no test that can accurately tell a person whether or not he will get dementia or heart disease or arthritis. The vast majority of diseases and disorders involve a complex relationship between genes, lifestyle and environment that no scientist understands. Having an "increased risk" of Alzheimer's disease on a genetic profile is, by no means, a reliable indicator of whether a person will ever develop it. But that information is likely to cause unnecessary worry and anxiety.
Of course, the companies involved would argue that knowing the risks, however small, is vital in helping people lead healthier lives.
Prof. Tim Caulfield, Canada research chair in health law and policy at the University of Alberta and all-round skeptic on consumer genetic tests, uses blood pressure as a simple example to refute those claims. High blood pressure is, after all, a major risk factor for heart disease and stroke, two of the leading causes of death in Canada. And yet, despite knowing that losing weight, being more physically active, cutting back on alcohol and tobacco can all reduce blood pressure, many people don't make those important changes.
In fact, Caulfield argues that consumer genetic tests actually take away from the truly exciting developments in the field of genetic testing, those that can have real and important impacts on peoples' lives. Just last week, Canadian researchers announced they have developed a new genetic test that can accurately predict which men are mostly likely to suffer a recurrence of prostate cancer. And when those important developments come along, it's highly unlikely you'll need to put your spit in the mail to take advantage of them. For instance, screening for BRCA mutations is targeted at specific women, those who have existing risk factors such as a strong family history of breast or ovarian cancer or Ashkenazi Jewish heritage.
Even though the U.S. FDA says 23andme can't sell health-related genetic tests to consumers because it hasn't proven the accuracy of its claims, there's no indication Health Canada will take that step here.
So keep this in mind: No one needs to spend their hard-earned money on consumer genetic tests that will likely only confuse and cause unnecessary concern. We already know the keys to living a healthier, better life. The trick is to follow that advice.