Test Results

What if you could go online, order a test kit in a box, and, based on the results, prevent disease and optimize your health? If that sounds too good to be true, that’s because it is, says human genetics faculty member Laura Hercher.

In a December 2007 Scientific American article, Hercher discussed a new trend in genetics testing: “nutrigenetics” companies that sell test kits directly to consumers, ostensibly determine their genetic predisposition to various health risks, and then tailor nutritional recommendations to each individual’s genetic profile.

“Their pitch is that if they look at your genes and your lifestyle—defined by a questionnaire—they can give you valuable advice about how to adjust your diet and your behavior to optimize your health,” Hercher says. “This is a good idea on paper, but there are a few problems.”

The test results could be helpful, but could also be misleading, she says. The tests turn up “tons of associative data, which are at best suggestive but often turn out just to be wrong.” The science behind the tests isn’t adequate to show a causative relationship between the gene variants and the tests’ outcomes.

By comparison, the test that geneticists use to detect the breast cancer gene can pinpoint a breast cancer risk as high as 85 percent. The commercial tests can only suggest an increased risk of a few percentage points.

“The best advice nutrigenetics companies can come up with, based on all these complicated, high-tech tests, is the same thing your mom would tell you: Eat your vegetables, exercise, and get enough sleep,” says Hercher.

“These tests are not exactly scams,” she says, “although some of them include pitches for overpriced vitamins and supplements that really are scams.”

And the downside to garnering information without interpretation by trained counselors is that “when people get predictions like this, they may either worry unnecessarily or, conversely, believe they have some immunity. Either misconception may lead them to make bad decisions.”

Predictably, there are pressures on companies to turn a profit from new genetic testing technology, and nutrigenetics tests can cost between $900 and $2,500. The companies selling the tests are private, so Hercher doesn’t have data on how many have been sold. But she does feel that “the potential is being oversold by commercial interests and the media, which may ultimately undermine the public’s faith in genetic testing.”

“I would recommend that people with specific concerns contact a genetic counselor or their doctor, or look for Web-based sources of information that are not-for-profit,” she says. “There are some companies like DNA Direct that do more conventional tests and are a good option for people who can’t or don’t want to go through medical channels.”

—Lisa W. Romano