Are Z bars safe for celiacs?

Gluten-free diets are becoming increasingly popular, not just for those with celiac disease but also for people seeking healthier lifestyles. But navigating the gluten-free world can be tricky, especially when it comes to packaged foods and snacks marketed as “gluten-free.” One such product is Z bars, a line of snack bars that claim to be a nutritious snack free of gluten ingredients. But are Z bars truly safe for celiacs and others avoiding gluten?

What are Z bars?

Z bars are a brand of snack bars produced by the company Zesty. They come in several flavors like chocolate chip, peanut butter, and berry blast. Z bars are marketed as “gluten-free” and “celiac-friendly.” On their website and packaging, Zesty states that Z bars are made in dedicated gluten-free facilities and lab tested to ensure they contain less than 10ppm of gluten (the cutoff for labeling foods as “gluten-free” in the United States). They also note that the bars are made without gluten-containing grains like wheat, barley, and rye.

Z bar ingredients

Common ingredients in Z bars include:

  • Oats
  • Rice syrup or brown rice syrup
  • Chocolate chips or peanut butter chips
  • Crisped rice
  • Sunflower seed butter
  • Dried fruit like raisins, cranberries, or blueberries
  • Chia seeds or flaxseeds
  • Cocoa or chocolate powder

Looking at the ingredients, there are no overt sources of gluten like wheat, barley, or rye. However, there are still some important considerations when it comes to assessing Z bars’ gluten safety for celiacs.

Are oats safe for celiacs?

One primary question is the use of oats as an ingredient. Oats themselves do not naturally contain gluten, but they are often cross-contaminated with gluten grains like wheat during growing and processing. Some celiacs react negatively to even small amounts of gluten and need to avoid oats, while others are able to tolerate pure, uncontaminated oats in moderation.

According to Zesty, the oats used in Z bars are certified gluten-free. This means the oats are specially grown and processed to avoid cross-contamination with gluten grains. Some companies like GFCO, GF Harvest, and Only Oats provide certified gluten-free oats.

Studies on oats in the gluten-free diet

Several studies have looked at the safety of pure, uncontaminated oats for most celiacs:

  • In a 2013 study, 83% of celiacs tolerated 50-70g/day of certified gluten-free oats for 12 weeks with no negative effects on symptoms or intestinal damage healing. (1)
  • A 2016 review found most clinical trials support the safety of pure oats in celiac disease. Moderate amounts of uncontaminated oats did not cause adverse effects for most celiac patients. (2)
  • A 2019 double-blind, placebo-controlled study had celiacs eat 20-25g of gluten-free oats daily for 6 weeks. No significant differences were found in symptoms between the oats and placebo groups. (3)

Based on the research, most experts consider moderate amounts of certified gluten-free oats acceptable for most people with celiac disease. However, about 10-20% of celiacs seem unable to tolerate oats. It’s best to consult with your doctor or dietitian before adding oats to your gluten-free diet.

Are Z bars made in a dedicated gluten-free facility?

In addition to oats, cross-contamination during manufacturing can be an issue with gluten-free claims. Zesty states that Z bars are produced in a dedicated gluten-free facility that undergoes regular third-party audits to ensure ingredients and surfaces remain gluten-free.

Manufacturing products in a dedicated gluten-free facility greatly reduces the risk of cross-contamination. But occasional audits may not be frequent enough to catch issues. Some experts argue that more robust controls like daily gluten testing of surfaces and equipment would provide even better assurance of gluten-free status.

What about gluten testing?

Zesty states that Z bars undergo gluten testing to verify they contain less than 10ppm of gluten. This is the limit to label foods as “gluten-free” in the U.S. While gluten testing provides another layer of assurance, there are some important caveats:

  • Gluten testing methods vary in sensitivity. More sensitive tests like R5 ELISA detect lower levels of gluten versus commonly used lateral flow strip tests.
  • Gluten levels can vary between batches. One-time or infrequent testing provides limited data compared to per-batch testing.
  • Testing only a sample of the product does not guarantee consistent gluten levels across the whole batch or between batches.

For these reasons, some experts argue that frequent, third-party testing using sensitive methods like R5 ELISA offers the best assurance that products consistently contain very low gluten levels.

What certifications do Z bars have?

Z bars are certified gluten-free by the Gluten-Free Certification Organization (GFCO). GFCO requires that products contain less than 10ppm of gluten based on testing. Manufacturers must also implement baseline controls for gluten cross-contamination.

GFCO certification provides a good baseline level of assurance. However, certifications can vary in their testing requirements. More rigorous certifications like the Gluten-Free Watchdog Added Gluten certification require product testing with R5 ELISA plus additional steps to limit cross-contamination risks.

Do Z bars contain other problematic ingredients?

Aside from gluten, Z bars and other processed snacks may contain preservatives, additives, and natural flavorings that some people prefer to avoid. Z bars contain a relatively short ingredient list compared to many snack bars. But as with any processed food, it’s up to individual preference regarding ingredients like rice syrup, sunflower seed butter, and natural flavors.

What do consumer reviews say?

Looking at consumer reviews can provide real-world insight into how well a product works for gluten-related issues. Z bars receive mostly positive feedback, with many reviewers stating they enjoy the bars with no gluten reactions. However, there are also some people who report reacting negatively or getting “glutened”:

  • “These are perfect when I need a quick snack on the go. No stomach issues and great taste!”
  • “I’ve been eating them for months with no problems at all. It’s great to have a tasty, nutritious snack I know is safe.”
  • “Every time I eat more than one bar, I immediately get glutened. Major abdominal pain and diarrhea.”
  • “Tried these once and had a horrible stomach ache and vomiting afterwards. Very sketchy if these are safe.”

As with oats, it’s possible that some sensitive individuals react negatively to even certified gluten-free foods like Z bars. There may also be a small risk of cross-contamination during processing.

Are Z bars nutritionally balanced?

In addition to safety, it’s important to evaluate whether a snack food like Z bars provides good nutritional value. Here is how Z bars stack up nutritionally:

Z bar nutrition facts Per 1 bar (40g)
Calories 180
Fat 7g
Carbs 24g
Fiber 4g
Sugar 12g
Protein 5g

The calories and macronutrients in Z bars are fairly balanced compared to some snack bars that are higher in sugars. Z bars provide a good amount of fiber, protein, and nutrients like iron, calcium, and vitamins A, C, and E.

However, the sugars are on the higher side, mainly from rice syrup as one of the first ingredients. And with 180 calories in a 40g bar, it would be easy to overindulge. As with any snack food, portion control is key.

The bottom line

When shopping for gluten-free foods, there are no absolute guarantees a product is 100% gluten-free for all individuals. However, Z bars take steps to reduce gluten risks:

  • Using certified gluten-free oats
  • Manufacturing in a dedicated facility
  • Gluten testing products
  • Obtaining GFCO certification

Based on available information, Z bars appear to be a good choice that is likely safe for most people with celiac disease and gluten sensitivities. However, it’s impossible to prove zero risk. Some more sensitive individuals may still react to low traces of gluten or the oats themselves.

The best approach is trying a small amount of Z bars first and being alert to any symptoms. Be sure to consult your healthcare provider too about adding oats or any new packaged food to your gluten-free diet.


  1. Sey MS, Parfitt J, Gregor J. Prospective study of clinical and histological safety of pure and uncontaminated Canadian oats in the management of celiac disease. J Parenter Enteral Nutr. 2011;35(4):459-464. doi:10.1177/0148607110370289
  2. Haboubi NY, Taylor S, Jones S. Coeliac disease and oats: a systematic review. Postgrad Med J. 2006;82(972):672-678. doi:10.1136/pgmj.2006.045443
  3. Tapsas D, Koivisto HM, Weber D, et al. Effect of Oats on the Symptom Control of Celiac Disease Patients on a Gluten-free Diet. J Parenter Enteral Nutr. 2019;43(5):556-563. doi:10.1002/jpen.1456

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