When former Yankee switch hitter Mark Teixeira bashed 31 home runs in 2015 and went to the All-Star Game, he credited a radically improved, gluten-free diet based on lean proteins and veggie smoothies. It worked for him.

But the millions of people across North America who have embraced a gluten-free diet — the number has tripled in the past few years, despite the fact that participants are neither gluten-sensitive nor diagnosed with celiac disease — may be sabotaging their health.

In a new study, published in the journal Epidemiology, researchers found that people who followed a gluten-free diet had twice the level of arsenic, a common component of many gluten-free grains, in their urine, and 70 percent more mercury in their bloodstreams than gluten eaters.

While not an immediate health threat, these changes can be a cause for concern.

When folks give up gluten-containing foods, they often substitute prepackaged products that are packed with concentrated, rice-derived substitutes like brown rice syrup. Rice often contains arsenic and mercury in small doses, but it can add up if you eat too much.

Fortunately, a study in the journal Digestion found that 86 percent of those who believe they're gluten-sensitive could tolerate it.

So check with your doc before going gluten-free. If you do, remember that only wheat, barley and rye, and their derivatives, need to be eliminated.

There's still a world of great substitutes out there that are usually arsenic- and mercury-free, including buckwheat pasta and whole grains like amaranth and the sorta-grain, quinoa