For example, “people do in fact change insurance purchasing behavior based on this information,” says Green. “We should be cautious as medical professionals not to dismiss those personal reasons, as long as we can convince ourselves it’s not harmful to offer this information.”
Green and his collaborators have also found that people who know they have the high-risk gene are more likely to take vitamins. “That’s fine, except that some types of supplements are highly unregulated and can be harmful,” he says. “You can easily imagine people trying to link results of genetic tests to the purchase of unproven vitamins that could at best take their money and distract them, and at worst could be harmful.”
Researchers caution that results from the study are not necessarily indicative of the general population. For example, Green’s team weeded out people who scored high on measures of anxiety and depression at the start of the study. And the study does not examine all of the potential drawbacks of testing. In an editorial accompanying the paper, Rosalie Kane, a public-health specialist, and Robert Kane, a physician, both from the University of Minnesota, in Minneapolis, say that people who test positive for high-risk genetic variants might be denied some types of insurance. The Genetic Non-Discrimination Act, passed last year, prohibits such discrimination in employment and health insurance, but not in life, disability, or long-term care insurance.
One of the other major concerns for the new generation of genetic testing is how best to deliver the results. In Green’s APOE4 study, participants learned of their risk through genetic counselors–but this may not always be possible as genetic testing becomes more widespread. “I would be interested going forward to see how people who received this information without counseling deal with it,” says Christman. “Some of the direct-to-consumer companies are doing this right now.”
In the lung-cancer study, McBride and her collaborators offered smokers who had a family member with lung cancer genetic screening for a variant associated with a higher risk of developing lung cancer. Information about the risks and benefits of the test, provided to help people decide whether to take it, as well as the results were delivered online.
The researchers found that all of the people in the study who tested high risk understood the meaning of the results, while only about 60 percent of those who scored low risk understood them. “That kind of defies expectation,” says McBride. “Psychological theories predict that people protect themselves from threatening information, and one way to do that is by not understanding it.”
The researchers found no difference between the high- and low-risk participants’ interest in getting additional tools to quit smoking. “Telling someone they are low risk doesn’t undermine their motivation to seek out cessation materials, and being told you are high risk didn’t increase motivation,” McBride says. “All smokers were motivated enough to log on and consider testing and availed themselves of cessation materials.”
McBride says that she doesn’t think genetic testing itself will motivate people to quit smoking or lose weight or make whatever changes might help their health. Instead, she says that the tests’ utility may be to motivate people to take initial steps–“to get someone engaged in a smoking-cessation program or dietary-change intervention.”
McBride is now studying the impact of genetic tests that analyze many spots on the genome and assess risk for multiple diseases, such as those offered by a number of online gene-testing companies. “There the story is much more complicated,” she says. “The results might conflict with each other, and people might be at risk for many conditions.”