Can Consumer Genetic Tests Predict Your Cancer Risk?

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Anyone can plunk down a few hundred dollars now and get a “personalized DNA test.” By knowing your risk for certain cancers, diabetes or other health conditions, say these companies, you can change your diet and exercise habits or your medical check-up schedule to help prevent these diseases.

Personalized medicine is the new buzzword and having your own DNA analyzed seems like it could be a good idea.

However, an investigation by the US GAO (Government Accountability Office) found misleading test results, deceptive marketing and questionable practices.  The GAO had found similar results in 2006, but repeated the investigation this year because companies were being touted as more reputable in the past few years.

What they did:

The GAO sent samples from five donors to four companies – each donor sent two samples, one with accurate information and one with different information about age, race or ethnicity.  Costs ranged from $299 to $999 per test.

What they found:

1.            Results varied from company to company:  for example one man’s results from the 4 companies showed very different levels of risk for prostate cancer.  Two companies reported average risk, one above average and one below average.

2.            Results conflicted with actual medical conditions.  One donor had type 2 diabetes, but three companies indicated he had an average risk for developing the disease.

3.            Some companies were unable to provide African American and Asian donors with results although that limitation had not been disclosed.

4.            Follow up consultations provided only general information – not the expert advice promised.

Genetics experts say these results confirm that personalized direct-to-consumer genetic testing is not yet ready for prime time.

You don’t have to wait for a genetic test to know that everyday choices you make now can reduce your risk for many cancers and other chronic disease.  Maintain a healthy weight, eat a plant-based diet and exercise at least 30 minutes every day.

To learn more about genes, diet, health and disease, read “A Closer Look at Nutrigenomics:  How Nutrients and Genes Interact.”

You can read the report here and hear clips of some claims made by company representatives.


    Author: Alice RD

    Alice G. Bender, MS, RDN, is the Director of Nutrition Programs at AICR. She helps put the science of cancer prevention by providing tips and tools to choose nutritious and delicious foods. Alice has guided thousands of individuals to healthier lives through diet changes and choices.

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