When DNA means 'do not attempt'.(up front: News / Trends / Advice)

New understanding of how genes contribute to certain diseases has spawned Web sites hawking at-home "nutrigenetic" DNA test kits. Using a DNA sample you take, usually by swabbing the inside of your cheek, the kits claim to analyze a limited number of genes, then provide diet and lifestyle tips tailored to your genetically determined risks. But a recent government report on kits from four such Web sites found that they're misleading at best, and cleverly disguised scams at worst.

For the report, by the Government Accountability Office and published in late July (available at www.gao.gov),the GAO bought 14 genetic tests for $89 to $395 each from four online vendors. It then used samples of DNA from a 48-year-old man and a 9-month-old girl to create 14 fictitious consumers with a range of ages, weights, heights, and lifestyles, and sent the samples for analysis.

What they found. The dietary and lifestyle recommendations supposedly based on those DNA samples proved little more than run-of-the-mill advice to eat right, exercise, and stop smoking. Advice based on DNA from the same "person" varied with the lifestyle profile investigators provided. (Smokers were advised to quit; healthy eaters, to keep up the good work.) Kits from one site predicted an increased risk of the same four diseases for three of the fictitious people whose DNA came from the two subjects.

Most disturbing, two sites recommended "personalized" dietary supplements costing at least $1,200 per year for all of the phony ...