Gluten Contamination of French Fries Cooked in Fryers Shared with Wheat Products

Celiac.com 04/18/2023 - The collective wisdom is that people with celiac disease should avoid eating French fries cooked in fryers shared with wheat products. But what's the real story? Is there any science to back up the idea? It turns out, there is. A research team recently assessed gluten levels in French fries that were free of gluten-containing ingredients, but were cooked in shared fryers with wheat-containing foods. Here's the rundown.

To do so, researchers bought 20 orders of fries from 10 different restaurants and tested them for gluten levels using two different ELISA tests. All the restaurants confirmed that their fryers were used to cook both gluten-free and wheat-containing foods.

Study Results Showed Gluten Contamination is Common when Gluten-Free Foods are Cooked in Shared Wheat Food Fryers

Celiac.com Sponsor (A12):
According to the sandwich ELISA test, gluten was found in 9 out of 20 fry orders, ranging from 7 to over 80 ppm gluten. The competitive ELISA test found gluten in 3 out of 20 fry orders, ranging from 14 to over 270 ppm gluten. However, the study also noted that ELISAs may underperform when analyzing for gluten that has been heated.

The findings suggest that one out of four French fry orders would not be considered gluten-free, which suggests that individuals with celiac disease may risk gluten exposure when eating fried foods cooked in fryers shared with wheat-containing foods. 

The study emphasizes the importance of informing individuals with celiac disease and other gluten-related disorders about the potential risks of consuming fried foods cooked in shared fryers, and the need for food service establishments to adopt policies to prevent gluten contamination.

This study is important for people with celiac disease, who must avoid gluten completely to manage their condition, and for whom even trace amounts of gluten can cause harm. The results suggest that many restaurants may not fully understand the risks of cross-contamination when cooking gluten-free foods in shared fryers. 

Unreliable ELISA Results for Heated Foods

This study also highlights the limitations of using ELISA tests to detect gluten in heated foods, as the tests may underperform in these situations. This may suggest that the actual gluten levels in the fries could be higher than what was detected in the study. 

Because of this, people with celiac disease need to be aware of this risk and probably want to avoid French fries, or any other products, cooked in shared fryers.

More research is probably needed to determine the exact extent and conditions of gluten contamination in shared fryers, and to develop better testing methods to accurately measure gluten levels in heated foods.

But even in the absence of further data, cross-contamination of gluten-free foods cooked in shared fryers is definitely an issue for people with celiac disease, and those affected should avoid eating any food that is cooked in a fryer that is also used to cook products that contain wheat.

Here's an article on where people with celiac disease or gluten sensitivity can get decent fast food French fries.