The online storefront for the consumer genetics company Orig3n features an image of a young lady facing toward a sepia horizon. Her tresses are wavy, her triceps enviably toned. Her determined posture complements the transcript floating beside her: “Take charge of your future, ” it reads. “Orig3n DNA tests uncover the links between your genes and how you think, act, and feel. The more you know, the easier it is to reach your highest potential.”
It’s the promise of a growing number of services: Genetic insights you can act on. There are tests tailored to tell you about your diet, your fitness, your complexion–even your wine predilection. Helix, another customer genetics company, sells a Wine Explorer service that recommends wine “scientifically selected based on your DNA.”
But researchers will tell you to approach lifestyle-tailored testing kits with extreme skepticism. “What you see in the interests of consumers genetics marketplace is that legitimate genetic findings, often from studies with very large sample sizes, are being turned around and marketed to people in such a way that connotes it’s going to be actionable for individuals, ” says Harvard geneticist Robert Green, who’s been researching direct-to-consumer genetic testing for closely connected to 20 years. But in most cases, he says, the extent to which consumers can act upon their results “really remains to be proven.”
Not that researchers aren’t trying. On the contrary: This week, scientists led by Christopher Gardner, director of nutrition studies at the Stanford Prevention Research Center, published one of the most rigorous investigations to date on whether dieters can use personal DNA results to identify more effective weight-loss strategies. The researchers compared the efficacy of low fat and low carbohydrate diets in a year-long randomized controlled trial involving more than 600 test subjects. And crucially, the researchers also looked at whether test subjects’ genes impacted their results. Earlier studies, some led by Gardner, had suggested that a mix of mutations in PPARG, ADRB2, and PABP2, three genes linked to the metabolism of fat and carbohydrates, could predispose test subjects to lose more weight on one diet than the other.
But the results, which appear in this week’s issue of the Journal of American Medicine, observed no association between test subjects’ genetic profiles and their success with either program; test subjects lost the same amount of weight, regardless of which diet they were assigned. And study participants who were assigned diets that “matched” their genetic profile fared no better than those who weren’t.