You've probably seen some scary headlines recently about how a gluten-free diet may expose your body to more arsenic and mercury—toxic metals that have been linked to a higher risk of heart disease, cancer, and neurological problems.
These reports were initiated by a study conducted at the University of Illinois. Gluten-free diets tends to include a higher intake of rice as a replacement for wheat products, and since rice may accumulate arsenic and mercury from fertilizers, soil, and water, the researchers set out to investigate the potential health implications of going G-free.
For their study, they identified 73 people (ranging in age from 6 to 80) who reported eating a gluten-free diet between 2009 and 2014, and tested their blood and urine. The researchers found that on average, those people had almost twice the concentration of arsenic in their urine and 70% higher mercury levels in their blood, compared to people who were not gluten-free.
The researchers concluded that there may be unintended consequences of the diet. But it's worth pointing out that their study was relatively small. It also did not look at whether rice was the main source of the metals in people's diets. What's more, we don't know the specific risks of having the levels of arsenic and mercury detected. The amounts of arsenic and mercury in both the gluten-free and non gluten-free eaters were much lower than those associated with arsenic toxicity or mercury poisoning,
The way I see it, this research doesn’t mean that going gluten-free will automatically increase your intake of the heavy metals. However it's an important reminder that how you eat gluten-free matters, both in terms of arsenic and mercury, and your overall nutrient intake. Here are three key ways you can optimize your health if you follow the diet.
Eat more whole, fresh foods
You can find gluten-free versions of nearly any food these days, including bagels, bread, wraps, baked goods, and crackers. Many are made with rice flour, but what they also have in common is that they’re all highly processed. If you need to follow a gluten-free diet, yes, it’s nice to be able to eat pizza or a cookie if you really want it. But these foods should be occasional treats, not daily staples. And it’s important to note that simply being gluten-free does not make a product healthy. Many processed gluten-free foods are made with refined flour (stripped of fiber, nutrients, and antioxidants), as well as added sugar, sodium, or other unwanted additives. Make whole, fresh, and minimally-processed foods your go-tos, not gluten-free versions of packaged, multi-ingredient products.
Vary your diet
Rice is just one of many gluten-free grains. Others include quinoa, buckwheat, millet, oats, sorghum, teff, corn, and amaranth. Pulses (the umbrella term for beans, lentils, peas, and chickpeas) are also gluten-free, as are starchy vegetables, including sweet potato, yams, fingerling potatoes, and squash. When planning meals, include a wide variety of these whole foods that are naturally gluten-free.
For example, instead of whole wheat toast at breakfast with your veggie and avocado omelet, opt for sweet potato toast, or a side of black beans. In place of a sandwich or wrap for lunch, make a salad and add a small scoop of quinoa or lentils for a healthy source of carbs. At dinner, replace pasta with spaghetti squash. And snack on roasted chickpeas or hummus with veggies rather than chips, pretzels, or crackers.
Consume low-mercury seafood
We don’t know the precise source of the mercury that caused the elevated levels detected in this study, but seafood can be a significant contributor in people's diets. One resource to help you figure out which seafood to avoid is the Environmental Working Group’s Consumer Guide to Seafood. Generally, low-mercury options include wild Alaskan salmon, Atlantic mackerel, rainbow trout, shrimp, and clams. Varieties with moderate mercury levels include cod, crab, canned tuna, lobster, mahi mahi, and sea bass. High levels of mercury are found in shark, swordfish, king mackerel, and grouper.
As with any diet, this simple motto can help you strike a healthy balance: Keep it real, mix it up, and don’t overdo it.
Cynthia Sass is Health’s contributing nutrition editor, a New York Times best-selling author, and consultant for the New York Yankees. See her full bio here.