THE CURE

There is a direct-to-consumer (DTC) genetic testing company that gives parents the opportunity to uncover their kids’ “hidden” talents. You can (allegedly) find out if your child has the genetic propensity for things like dancing, passion, intelligence, self-reflection and even teenage romance. The company suggests that this information is valuable because it “will help you take control and maximize the development of your child,” including personalizing “discipline strategies” and career guidance so you can maximize your “returns on your investments” (because, let’s face it, kids are a financial sinkhole).

This is all scientifically absurd, of course. And any product based on the principle of having your kids do what you tell them seems destined to disappoint. Has the marketing team ever met a teenager?

But, despite the lack of evidence, these kooky kinds of DTC services continue to proliferate and have become big business. In China, for example, there has been a rise in genetic testing as many parents take their kids to “talent detection” facilities in the hope of gleaning information to inform education and career decisions.

There are now DTC genetic testing companies that will use your DNA to select your exercise routine, diet, life partner (seriously), anti-aging products and even wine and beer. As many have noted again and again and again and again, there is very little science to support any of it. Yes, genes are often involved in these human traits and tendencies, but the relationship is fantastically complex and the identified genes are rarely predictive in any meaningful way. (And there is often a cheaper, simpler and more enjoyable way to obtain information that is reasonably predictive. For example, want to know how fast your kid is? Have her run. Want to know if you like a particular wine? Um, drink the wine.)

To be fair, the bulk of the DTC testing industry isn’t focused on things like personalized Pilsner. The highest-profile companies, like 23andMe, are offering services meant to improve health and predict future health risks. But even in this context, the value is far from clear. Indeed, Choosing Wisely Canada — an entity with the mandate to help clinicians make evidence-informed choices and avoid unnecessary testing and procedures — recently warned Canadian physicians against making medical decisions based on DTC genetic test results.

This recommendation is based largely on concerns about the accuracy, reliability and clinical value of these tests. But another significant limitation (and one that I’ve written about often) is that they simply don’t have an impact on health behaviours. A key message in the marketing for these DTC services is that genetic information is important because it will allow you to develop a “lifestyle that will be effective in reducing your health risks to certain diseases” or, as another DTC company puts it: “Knowing which genetic disorders and diseases you are at risk from will allow you to plan to reduce it by making lifestyle changes such as diet and exercise.”

But study after study has found that humans simply do not react this way. Changing behaviour is hard. Really hard. For example, a recent study from the University of Cambridge concluded that receipt of genetic risk information “did not affect participants’ physical activity or other relevant behaviours.” A 2017 study found that “genetic information did not appear to influence” nutrient intake (this study was focused on omega-3).

To be honest, I’m not sure if these services will ever have any broadly applicable practical health value.

Yes, there have been a few studies that have shown modest behavioural changes, such as a recent study of DTC consumers that relied on self-reported data. But the overall message from the available data is that this genetic information doesn’t do much — which, given that this is the core promise of the DTC industry, is a pretty remarkable, and wilfully ignored, conclusion.

To be honest, I’m not sure if these services will ever have any broadly applicable practical health value. In the best-case scenario, they provide an opportunity to engage the topic of genetics, explore health prevention strategies and have a bit of fun with science. But even in this context — a scenario that is often called recreational genetics — I worry that DTC services still serve mostly as a source of hype, adding more confusion than clarity about the role of genes and the elements of a healthy lifestyle. (Spoiler alert: Don’t smoke, exercise, eat a healthy diet, sleep, have good relationships.)

We need more trusted sources speaking up, as Choosing Wisely just did with its recommendations regarding DTC health testing, about the limited value of these products. Given the continued hype that surrounds genetics and the unrelenting pressure on the research community to find ways to commercialize its work, I am certain that new DTC services will continue to emerge.

Here’s an idea: How about a DTC test to find out if you’ll like movies starring Dwayne “The Rock” Johnson? Just think of the money you could save! (Confession: I have the gene.)

Photo: Shutterstock/Khakimullin Aleksandr


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