How Much Gluten Can Make Me Sick?

When faced with a diagnosis of celiac disease, people will often ask their healthcare providers how much gluten they're allowed to eat. Unfortunately, there's neither an easy answer to the question nor a one-size-fits-all strategy that will work for everyone. In the end, it's not so much about how much gluten you can eat but rather how little it may take to negatively impact you.

A slice of bread on white background
Isabelle Rozenbaum / Frederick Cirou / Getty Images

The Threshold for Safe Gluten Intake

While the typical Western diet consists of 10–20 grams of gluten per day, some people can get very sick by eating even a tiny amount of regular bread or other gluten-containing foods.

Studies over the years have conflicted with what they consider to be "safe" thresholds for gluten intake on a gluten-free diet. Some have suggested that 625 milligrams (mg) per day (roughly one-fifth a slice of bread) is perfectly fine, while others raise the red flag at anything over 10 mg per day (1/350th of a slice).

But it's not just the amount of gluten that's concerning. Researchers are starting to understand that the negative effects of gluten tend to be cumulative in people with celiac disease. Even when intake is as low as 50 mg per day (roughly 1/70th a slice of bread), the daily, low-level consumption of gluten was as much associated with intestinal erosion (villous atrophy) as a single, excessive event.

A study conducted at the University of Maryland's Center for Celiac Research found that people who consumed 50 mg of gluten per day developed villous atrophy after just 90 days. By contrast, those who consume either 10 mg or no gluten had no significant changes to their intestinal lining.

Based on research findings, you could reasonably assume that the daily intake of 10 milligrams of gluten would likely be enough to avoid illness. And, in most cases, it does.

When 10 Milligrams a Day Is Still Too Much Gluten

Even in the best of circumstances, a "gluten-free" diet is rarely 100% without gluten. Gluten cross-contamination is common whether in kitchens or restaurants, and even the U.S Food and Drug Administration (FDA) allows for some gluten in "gluten-free" products, specifically 20 parts per million gluten or less.

As a result, a person eating a typical, gluten-free diet will consume anywhere between 6 milligrams and 10 mg of gluten per day. While that would seem well within the safe zone, it may still be too much for those with extreme gluten intolerance.

As part of its own research, the FDA reported that intestinal damage for those with high gluten sensitivity started at only 0.4 mg of gluten per day. Moreover, symptoms of gluten intolerance could begin as low as 0.015 mg.

This suggests that people with this level of intolerance may need to take extreme measures to avoid any traces of gluten in their food and kitchens.

How to Figure Out the Right Amount of Gluten For You

Gluten intolerance can vary by the individual. At one end of that spectrum, you have people with the silent celiac disease who can eat almost anything and never get sick. At the other end, there are those who are extremely sensitive to the point where eating becomes more of a challenge than a pleasure.

Figuring out what's right for you can be a process of trial and error. While it may take time for you and your healthcare provider to find the ideal threshold, your ability to avoid symptoms can prevent many of the longer-term complications of the disease, including the loss of bone mass, gallbladder problems, and pancreatic insufficiency.

So try to focus less on what you have to give up and more on what you stand to gain. With patience and diligence, you'll eventually find a diet that allows you to enjoy both improved health and a better quality of life overall.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cohen IS, Day AS, Shaoul R. Gluten in celiac disease-more or less?. Rambam Maimonides Med J. 2019;10(1). doi:10.5041/RMMJ.10360

  2. Food and Drug Administration Office of Food Safety Center of Food Safety and Applied Nutrition. Health hazard assessment for gluten exposure in individuals with celiac disease: determination of tolerable daily intake levels and levels of concern for gluten. 2011.

  3. Singh VK, Haupt ME, Geller DE, Hall JA, Quintana diez PM. Less common etiologies of exocrine pancreatic insufficiency. World J Gastroenterol. 2017;23(39):7059-7076. doi:10.3748/wjg.v23.i39.7059

By Jane Anderson
Jane Anderson is a medical journalist and an expert in celiac disease, gluten sensitivity, and the gluten-free diet.