Gluten Detectors and Test Kits: Nima, EZ Gluten, and GlutenTox Home

Have you ever ordered a meal at a restaurant or sat down with friends at their dinner table, only to wonder if the food—billed as gluten-free—would make you sick the next day? Have you ever tried a new product—perhaps one with no gluten ingredients but lacking a "gluten-free" label designation—only to discover through a bad reaction that it wasn't quite as gluten-free as you expected?

If either of these scenarios ever has happened to you (and if you've been following the gluten-free diet for more than about a week, you've certainly been in situations like these), then you've probably wished for a way to test your food for the gluten protein before you ate it.

Well, there's good news and bad news: Yes, you can buy home gluten test kits and devices, and when properly used, they will tell you whether the food in question has gluten in it or not. But these testing methods aren't cheap, they may give you false positives (indicating a food has gluten in it when it actually doesn't) and false negatives (indicating a food doesn't have gluten in it when it actually does).

Finally, some of them are a bit involved... which means they might not be so easy to use at the dinner table.

Here's a detailed rundown of the three gluten testing options on the market right now—Nima, EZ Gluten, and GlutenTox Home—including their costs, benefits, and drawbacks.

Nima Gluten Tester

The Nima gluten tester is a battery-powered, rechargeable device small enough to fit in a pocket or purse. To use it, you load it with a one-time-use disposable testing capsule, insert a large crumb-sized sample of the food you want to test, and wait for about three minutes until the testing is complete.

Once the little device has finished its work its display will light up, either with a smiley face (e.g., the food is gluten-free) or with a wheat icon and the text "gluten found."

It's possible to test almost every type of food with Nima, including baked goods, fried items, soups, sauces, and desserts. You also can sync the tester with your iOS device, which allows you to review your own test results and contribute to a crowd-sourced database of test results.

Benefits and Drawbacks of Nima

Sounds pretty great, right? The Nima truly is revolutionary, and the company deserves credit for tackling a difficult problem in a way that's really user-friendly and portable.

Nima is easy to use (most people wouldn't hesitate to set it on a table at a restaurant and test away), and its results are easy to interpret. There's no question that it would save you if your server accidentally brought you chocolate cake containing gluten or vegetable soup with barley. However, Nima does has some downsides.

First, it's expensive to buy and expensive to use. The device itself, which comes with a starter kit of three disposable testing capsules, a micro-USB cable, and a carrying pouch, retails for $279 (prices subject to change). That provides you with the tools to test three foods for gluten (and remember, if your restaurant meal consists of soup, entree, side dish, and dessert, you'll have to test each one separately, using one capsule for each). Nima offers 12-capsule packages for around $75, or you can purchase a monthly capsule subscription for around $60 (12 capsules shipped every other month) to around $120 (24 capsules per month).

Second, Nima only tests food to the legal limit of fewer than 20 parts per million of gluten; if the food in question contains some trace gluten but its gluten content falls below that legal threshold set by the U.S. Food and Drug Administration, Nima will still display a smiley face. However, many people in the gluten-free community react to trace gluten below 20 parts per million. If you're one of them, Nima may not work well for you, since it won't detect gluten below that 20 parts per million threshold.

Third, the device also won't necessarily detect inconsistent gluten cross-contamination in foods. That's just the nature of cross-contamination—if a small crumb of crouton fell into your green beans in the restaurant's kitchen, you'll only detect that crumb if it happened to be part of the green bean sample you tested in Nima. So you might get a false sense of security from testing food with the device.

Should you purchase Nima? If you travel and dine out quite frequently, and especially if you're not very sensitive to trace gluten, it might be a good investment in your health. It also might be a good investment if you've been diagnosed with celiac disease but you don't get an obvious reaction to gluten—in that case, it could help you avoid foods that harm you without you even realizing they're harmful. If, on the other hand, you rarely eat out, or if you're particularly sensitive to trace gluten, Nima's probably not worth it for you.

EZ Gluten Test Kits

Long before Nima hit the market, people in the gluten-free community were using EZ Gluten test kits to check products for gluten cross-contamination. In fact, many people with celiac disease and non-celiac gluten sensitivity relied on these tests to find safe products back before the U.S. Food and Drug Administration approved legal standards for gluten-free foods.

EZ Gluten will detect gluten levels as low as 10 parts per million—half as much as Nima.

Using the test kits is somewhat involved. First, you need to grind the food sample in question to a fine consistency (this is designed to spread any gluten contamination throughout the sample to be tested so that it's detected). Second, you add the sample to a liquid solution in a small tube and mix it thoroughly. Third, you place a few drops of that mixture into a test tube. Fourth, you place the kit's test strip into the test tube and allow it to absorb the mixture. And fifth, you wait 10 minutes to see what the test strip shows.

Interpreting the test strip's results requires some practice, as well. Although the test strip looks somewhat like a pregnancy test, it includes three lines, and various combinations of these lines mean different results, ranging from "negative" to "high positive" and "very high positive." There's also a result that means "invalid test." A very faint positive result can require a magnifying glass to detect.

You also can use the test kits to test for gluten cross-contamination on a surface, although doing so requires the use of sterile test swabs.

Benefits and Drawbacks of EZ Gluten

EZ Gluten's main benefit is that it's sensitive to lower levels of trace gluten. Many people with celiac disease and gluten sensitivity find they react to gluten levels well below the less than the legal standard of 20 parts per million currently allowed in gluten-free products, and EZ Gluten can help you pinpoint a reaction or identify products with lower gluten levels than that standard.

The test strips do have some drawbacks, though. First, like Nima, they're expensive. A two-pack costs around $25 on the company's website and a package of 25 test kits retails for approximately $262.

Second, they're pretty involved to use—so much so that it's unlikely you'd whip out a test kit in a restaurant and test away. Since the test takes about 15 minutes to perform, your food would be cold before you had finished testing it (you certainly could test takeout foods at home, however). And, there's a bit of a learning curve involved in performing and interpreting these tests.

EZ Gluten is best suited for use at home, on a kitchen counter or table, to help you identify manufactured products that meet your particular gluten-free needs. For example, you could use a test kit to see if a sauce that has no gluten ingredients is actually gluten-free (down to the testing limits of 10 parts per million).

GlutenTox Home Test Kits

GlutenTox manufactures professional-grade gluten tests along with a consumer version of its technology, GlutenTox Home. GlutenTox Home will detect gluten as low as 5 parts per million. That makes the test twice as sensitive as EZ Gluten and four times as sensitive as Nima.

Using GlutenTox Home is quite involved—it's similar to, although a bit more complicated than, using EZ Gluten. First, you grind up your sample into a fine powder. Second, you add a measured amount of your sample to the extraction vial and shake it for at least two minutes. Third, you use a dropper to take part in the solution from the extraction vial and drip it into the dilution vial. Fourth, you shake the dilution vial mixture gently for at least 15 seconds. Fifth, you use a new dropper to drip five or six drops of the dilution vial mixture into the vial's cap. Sixth, you dip the test strip into this mixture. And seventh, you wait 10 minutes to see what the test strip reveals. The entire process takes upwards of 20 minutes.

The GlutenTox test strips themselves are somewhat easier to interpret than the EZ Gluten test strips. There are two lines: a blue control line (which shows you the test is working properly) and a pink positive result line (which only appears if there's gluten in the sample). The pink line will appear darker if there's more gluten and lighter if there's not very much gluten. Again, a magnifying glass can come in handy to identify very faint positive test results.

Benefits and Drawbacks of GlutenTox Home

GlutenTox Home is far more sensitive to trace gluten than either EZ Gluten and Nima. That's its main benefit.

Its drawbacks include lack of testing ease (it's significantly more difficult to use than Nima and requires a more involved process when compared to EZ Gluten) and its cost. As with EZ Gluten, you're unlikely to pull out a test kit and grind up your dinner roll with a mortar and pestle at a restaurant table or in your friend's kitchen. However, GlutenTox Home could be a useful tool for those who are particularly sensitive to trace gluten, since it can be used to identify food products with little or no trace gluten in them. It also can be used to test surfaces.

Like Nima and EZ Gluten, the GlutenTox Home test kits are expensive: They range in price from $32 for two kits to $135 for ten kits.

The Bottom Line

Gluten testing can be a useful tool to help you weed out food items that may make you sick. However, it isn't a substitute for basic due diligence: talking to managers and chefs at restaurants, carefully choosing products at the grocery store, and avoiding iffy situations at friends' and relatives' dining tables.

If you decide you do want to experiment with gluten testing, you have three good choices: Nima, EZ Gluten, and GlutenTox Home. Nima is the clear choice if you want the ease of use, while GlutenTox Home allows detection of the lowest levels of gluten. EZ Gluten falls in the middle, with decent sensitivity and a testing process that's less involved than that of GlutenTox Home. Your ultimate choice will depend on your testing priorities.