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You get unnecessary tests

As with vitamins and minerals, more does not always mean better when it comes to medical tests. Especially tests marketed directly to consumers, like the cardiac calcium-scoring test. While this test—a CT scan that identifies calcium deposits in the heart arteries—is useful for a select group of at-risk people, it isn't for everyone, says Dr. Rogg. It also exposes you to a whopping amount of radiation—the equivalent of 25 to 50 chest X-rays.

Several US medical specialty groups have launched an initiative, Choosing Wisely, to draw attention to overuse of 45 medical tests, and encourage physicians to avoid tests and procedures of questionable benefit.

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