Can Your DNA Tell You the Healthiest Way to Live Your Life?

      First, there was the grapefruit diet—promising that the tart monotony of grapefruit after grapefruit would finally reveal your abs. There were more: Atkins, Blood Type, Dukan, Whole30, each with it’s own claim that a one-size-fits-all regimen is the answer to longevity and better fitting pants. But what if there were a way to determine, away from the citrus fruit mongers and peppy SoulCycle fanatics, the best way to live a healthy life? What if the answer were personal, buried in your genes?

      A decade ago, companies like 23andMe entered the empty, unregulated field of personal genetics with a limited purpose: to satisfy their customers’ curiosity. Their tests provided answers to the few, narrow questions that could be answered by genes — some fun (How much Neanderthal DNA do I have? Are my ancestors really from Spain?), and some serious (Is my child at risk for Tay-Sachs?).

      Like the questions, the tests were finite. You read your report and, curiosity satiated (actually, we’re Greek!), put the results away, letting them gather dust in a drawer.

      No longer. A new breed of startups has arisen, based on the premise that there are innumerable ways to spin our genes into concrete answers. The organizing body behind a cluster of these companies is Helix, a genomics startup that plans to launch a veritable app store of genetic data this summer. Where other companies have used DNA analysis for a one-off test, Helix will house results so that they can be shared with any number of partners, which will in turn use those results to offer answers to any number of questions — from personal preferences (companies like Exploragen will offer DNA-tailored dining experiences) to family planing (Jumpprovides cute predictions of what your future offspring might look like).

      “The next great discovery is you,” reads Helix’s website.

      As the field has grown more sophisticated, so, too have the questions. A slew of genetic tests has created a cottage industry of self help, promising to spin results into action plans. Imagine if, instead of blindly hopping from Atkins to Whole30 in the hopes that one will be the secret to weight loss and glowing skin, you could feed your DNA and an app would sort out the answers ahead of time. If you were at risk for iron deficiency, it might tell you to eat spinach; if your Achilles tendon were at risk for a tear, it would tell you to stretch your calves before running.

      It’s a tantalizing promise for the Goop generation: personally optimized wellness, with a regimen catered to your DNA. These companies claim to be able to tell you the secret to getting into shape—exactly what fitness fads have failed to do for years. And that secret, the people behind these startups say, has been hiding in your genes all along.

      A quest to live optimally healthy life might begin with some experts. A personal trainer or a nutritionist can advise you on the best ways to eat and exercise. But Avi Lasarow, the CEO and founder of DNAfit, argues that these experts can only go so far, given that their regimens are based on what has worked for other clients in the past. “When you have a genetic test, it guides you much better into what would work for you and what wouldn’t,” says Lasarow, whose startup offers tests for diet, fitness, and wellbeing, priced between $159 to $399.

      Making what Lasarow calls “the right choices” requires information — which companies like his make it easy to get. For a few hundred dollars you can purchase a spit test. A quick swab of your inner cheek, and lab technicians have what they need to make copies of your DNA and then fracture those copies into manageable segments. A company sorts through your genetic variants (called single-nucleotide polymorphisms, or SNPs) that correlate to specific traits. After a few weeks, you get the results through an online portal or in a PDF, showing the traits in your DNA that have health implications.

      Though DNA analysis is a standardized process, each company picks the variants that it thinks provide answers. One company might decide that one variant signifies caffeine sensitivity, or the likelihood that you might feel hungry after eating a full meal; both translate easily into advice. (Lay off the caffeine! Stop eating even if you’re still hungry.) Other results might help tailor a workout. Someone with an SNP that correlates to difficulty building muscle might add strength training or additional supplements.

      Of course, geneticists have argued, ad nauseam, that it’s impossible to trace a trait to a gene in a direct linear process. Though some genetic variants are solidly associated with particular traits, for more of them the evidence is mixed. And even if you assume that all the loose associations scientists have found between variants and traits are correct, they don’t fully explain why humans vary so much. Alun Williams, a reader in sport and exercise genomics at Manchester Metropolitan University, told me that tying traits to DNA is like absorbing a book by reading only one word per page — you have information, but at the end, you have no idea what the book was actually about.