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Saturday, April 9, 2005 - Page updated at 12:00 a.m.Personal DNA tests helping dieters fit into their genesBy Ariana Eunjung Cha
The Washington Post
Howard Coleman, Genelex founder, foresees change.The boxes arrive in the mail by the dozens each day and are stacked in neat rows in the laboratory. Inside are swabs of the inside cheek, drops of blood, material that the senders hope will give them a peek at the life they have been dealt by their genes.
Over the next few weeks, Genelex technician Dascena Vincent and her Seattle colleagues will conduct what they call a nutritional genetic assessment, analyzing the DNA samples for certain deficiencies. Problems in the genes that handle dietary fats? That could put you at risk for heart disease. Trouble with those that help rid your body of toxins such as smoke? Cancer could be an issue later in life. And how about those associated with metabolizing vitamin D? Be watchful for signs of deteriorating bone strength.
Based on the findings, the company provides recommendations on diet, lifestyle changes and categories of medications that might work best for an individual. Depending on how many tests the customer has ordered, the bill — typically not covered by insurance — could be $400 or more.
Companies such as Genelex are pushing medical science into territory that once was the realm of gods and horoscope writers. They are making predictions about what someone's health might be in five, 10, 20 or more years. Other testing facilities offer genetic assessments of what they claim is people's future propensity toward diabetes, liver disease, blood clots, dementia — even alcoholism and gambling.
There are now tests for more than 1,100 ailments, double what was on the market five years ago, according to GeneTests, a public-education service based at the University of Washington and funded by the National Institutes of Health.
Until recently, genetic testing was limited to pinpointing mutations associated with diseases such as Huntington's or cystic fibrosis. Today's analyses are more about probabilities and "what-ifs."
The allure of the new tests, say physicians and consumers who have taken them, is that they give people a sense that they can change their fate by taking preemptive action. The soaring popularity of such tests is fueling a new "DNA diet" craze with health clinics in Los Angeles and New York offering meal and supplement recommendations based on your genes and boosting the sale of self-help books such as "Feed Your Genes."
To some, the assessments are the first results of the advances scientists promised when they declared that they had mapped the human genome in 2000. "The adoption of genetic testing has the potential to radically transform health care. It will be the end of one-size-fits-all medicine," said Howard Coleman, Genelex's founder and chairman.
Other scientists worry that the commercialization of the nutritional genetic tests is premature.
They say that while some tests may have a valid scientific basis, others are based on research that is less universally accepted or even has been contradicted by subsequent studies. They also say our understanding of the interplay between genes, lifestyle and environmental factors is weak, and they fret that consumers might take the results too literally. By adjusting their lives based on the results, patients may end up doing more harm than good.
Critics also say privacy laws related to genetics aren't strong enough, putting those who take the tests at risk for discrimination. And they say there isn't enough regulation governing what companies can and cannot purport to know, leaving consumers vulnerable to being scammed. The Food and Drug Administration (FDA) does not have authority over the claims companies can make about the tests, although a bill is pending in Congress to give the agency that power in direct-to-consumer advertisements.
The critics emphasize that there's no clear research that shows the tests are any better at predicting future health problems than a simple survey of family history combined with ordinary lab workups.
"That these type of genetic tests have a high predictive value is a myth," said Sujatha Byravan, executive director for the Council for Responsible Genetics, a think tank in Cambridge, Mass.
Barbara Brenner, executive director of San Francisco-based advocacy group Breast Cancer Action, said the marketing of some of the genetic assessments is unethical: "The fear of disease and amount of misinformation about what we can do about it is leading a lot of people to needlessly take the tests."
Among the most passionately debated aspects regarding genetic tests is whether they should be sold without buyers having to go through their doctor or a genetic counselor.
Great Smokies Diagnostic Laboratory in Asheville, N.C., which offers tests similar to those of Genelex, requires that customers go through a professional. They say the results can be confusing or scary if not understood. But Genelex and plenty of others allow consumers to request the tests, because they say it empowers patients and ensures their privacy.
But Columbia University medical professor Nancy Wexler, who discovered the Huntington's disease gene, says direct-to-consumer sales are "a catastrophe." As a result of tests that predict a negative outcome, people might "cut off their best friends, jump off the Golden Gate Bridge." They also might decide not to have children because they are worried they will pass on similar health problems.
Wexler said the psychological impact of genetic testing can be as dramatic as the physical.
"Even if the test can save your life, it's often not good news," she said. "It knocks people for a loop."
