美国国家公共电台 NPR Do DIY Medical Tests Promise More Than They Can Deliver?（在线收听）

RACHEL MARTIN, HOST:

A growing number of startups are trying to drive a revolution in lab testing. You can buy a test to check your thyroid, sleep hormones or even vitamin deficiencies from the privacy of your own home. But these online ventures may be promising more than they can deliver. Lesley McClurg from member station KQED in San Francisco explains.

LESLEY MCCLURG, BYLINE: Last year, Regina Du took a home test that she says changed her life.

REGINA DU: How much better would I have felt these last eight years had I done this earlier?

MCCLURG: She used to suffer daily from stomach aches, crippling headaches and rashes.

DU: I would just, like, uncontrollably scratch myself because I was so itchy.

MCCLURG: Doctors could not figure out what was wrong, so Du poked around online and found a food sensitivity test for a couple hundred bucks from a company called EverlyWell. Here's the company's CEO, Julia Cheek.

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JULIA CHEEK: Collect your sample at your convenience at home, and send it back to one of our certified and accurate partner labs.

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MCCLURG: Du pricked her finger and sent off a few drops of blood in less than 20 minutes. She did it on her lunch break at her job in San Francisco. A few days later, she got an email listing foods to avoid.

DU: Gluten, malt, cheese, anything dairy - and green beans.

MCCLURG: And it seems to have worked. Since Du cut these foods, all of her symptoms have disappeared. The test was supposed to measure how her immune system reacted to certain foods by making an antibody called IgG. The idea is a high level of IgG correlates to symptoms like headaches, and bloating or joint pain. The problem is, there's very little science to back this up, and the test has not been approved by the FDA. Neha Shah, an immunologist at Stanford University, is very skeptical.

NEHA SHAH: I personally do not rely on these IgG tests because I don't think they've been validated.

MCCLURG: The professional association of allergists agrees. The organization does not recommend food sensitivity testing. Shah shares the story of her sister, who bought a test and then was told to avoid swordfish.

SHAH: We've been vegetarian all our lives, and there was really no reason why she should've had a high sensitivity, a high IgG level against swordfish.

MCCLURG: But EverlyWell stands by their products as an empowering first step for patients. Marra Francis is the company's executive medical director.

MARRA FRANCIS: A lot of times, this testing can be a bridge between vague symptoms and an actual plan that you create with your provider.

MCCLURG: The company markets 22 other home tests. You can check cholesterol, metabolism, testosterone. And you can get a similar lineup from Internet ventures like LetsGetChecked and Thorne, but most of these home test kits are not regulated by the FDA. Norman Paradis is a physician at Dartmouth College. He worries about this growing market.

NORMAN PARADIS: A lot of this kind of hucksterist (ph) testing is keying off of the placebo effect.

MCCLURG: In other words, just believing a test is valid and taking action on it may make you feel better. He's also worried that home tests could cause patients to overreact to test results by, say, taking a vitamin in toxic doses or seeking medical care they don't need.

PARADIS: For instance, let's say a test inaccurately said, you may have colon cancer, and then you went and got a colonoscopy and were injured during the colonoscopy. Well, the test actually created that harm.

MCCLURG: Paradis says patients shouldn't try to test their way to better health. If you want to feel better, he suggests starting with the basics - change your diet, set a regular sleep schedule, get some exercise. For NPR News, I'm Lesley McClurg in San Francisco.

(SOUNDBITE OF GEOTIC'S "VAULTED CEILING, PAINTED SKY")