Why Did Nobody Seem to Have a Gluten Problem in the ’90s?

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I grew up in the ’90s. I don’t remember gluten-free menus. I don’t remember kids bringing special bread to school. I don’t remember anyone talking about gluten at all.

Today, gluten-free products take up whole sections of the grocery store, and it can feel like every third person you meet has “a thing with gluten.” So what happened? Why is everyone gluten intolerant now?

The answers you usually hear are either smug (“it’s a fad”) or scary (“they ruined the wheat”). Neither is good enough if you or your child actually has celiac disease. The story people believe about that shift shapes how seriously your diagnosis gets taken, by a server, by a relative, and sometimes by a doctor.

So for the first LGGF Investigates, I did what I would want a friend to do. As a registered nurse, I went back to the primary research: blood samples frozen in the 1950s, national survey data, wheat-breeding trials, and the randomized studies on babies and gluten. Then I graded every explanation on the evidence.

Key Takeaways

• It was there, just invisible — a late-’90s study found celiac antibodies in 1 in 250 healthy US blood donors, while one well-studied Minnesota county had diagnosed only about 1 in 4,600 people by 1991.
• It also really increased — blood frozen in 1948–54 showed undiagnosed celiac at about a quarter of the rate found in comparable men decades later, and our genes can’t change that fast.
• The biggest change was outside celiac — Americans avoiding gluten without celiac roughly tripled between 2009 and 2014, while celiac itself held steady near 0.7%.
• “Modern wheat” has the weakest case — there is no good evidence wheat’s gluten content rose, and US flour use peaked in 1997.
• Test before you quit gluten — celiac testing is only reliable while you are still eating gluten, so cutting it first can hide the answer.

What Changed Since 1990

Before the evidence, the scene. Drag the slider from 1990 to today, or press play, and watch what changed around the people who had celiac disease all along.

The Suspects, Graded on the Evidence

Here is every theory we found for the gluten explosion, from the textbook to the viral, laid out as an evidence file. Each one gets an exhibit number and a stamped verdict.

What We Know: It Was Hidden, and It Grew

The first answer to “why did nobody have it?” is that plenty of people did. They just didn’t know.

When researchers screened 13,145 people across the US, the 2003 multicenter study in Archives of Internal Medicine found celiac disease in 1 in 133 people with no risk factors at all. A 2001 survey of 1,612 Americans with celiac found symptoms had started a mean of 11 years before diagnosis.

Even at the late-’90s blood-donor rate of 1 in 250, a school of 500 kids would statistically have had two. They may have been the kids with “a sensitive stomach,” the tiredness nobody explained, or the slow growth everyone blamed on genes.

But hidden cases are only half the story, and this is the part that surprised me most. In 2009, researchers thawed blood drawn from 9,133 people at Warren Air Force Base between 1948 and 1954 and tested it for celiac antibodies. The study in Gastroenterology found undiagnosed celiac in 0.2% of them, compared with 0.9% of similar men tested decades later.

Nobody in either group had been diagnosed, so better testing cannot explain that gap. Celiac disease really did become more common. Finland saw the same thing: total prevalence nearly doubled between 1978–80 and 2000–01, and the researchers concluded the rise could not be attributed to better detection.

Better tools then pulled those cases into the open. Researchers identified the protein celiac antibodies attack in 1997, the FDA cleared the first test kit built on it in 1998, and a 2004 NIH panel called celiac “greatly underdiagnosed.” If you want the full prevalence story, our deep dive on whether celiac disease is actually more common now goes number by number.

What We Know: A Bigger Group Started Avoiding Gluten

The other half of what you noticed has very little to do with celiac. In the national NHANES health survey, which tests every participant’s blood, the share of Americans avoiding gluten without celiac went from 0.52% in 2009–10 to 1.69% in 2013–14. The 2016 analysis in JAMA Internal Medicine found celiac itself held steady over the same years.

The culture moved even faster than the diet did. In 2013, 30% of US adults told the market researcher NPD Group they were trying to cut down on or avoid gluten. Mintel found 65% of gluten-free buyers that year thought the food was healthier, and 27% were buying it to lose weight. “Wheat Belly” (2011) and “Grain Brain” (2013) both hit number one on the New York Times bestseller list.

Some of those people do react to something. Gluten sensitivity without celiac got its formal classification from an expert panel in 2012, and a subset of people who report wheat sensitivity show blood markers of gut-cell damage that improve off wheat. But in blinded challenges, only 16 to 30% of people who report gluten sensitivity react to gluten specifically, according to a 2025 review in The Lancet.

The rest is often something else. In a 2018 Oslo trial in Gastroenterology, 59 people on self-started gluten-free diets ate hidden gluten, fructans or placebo for a week each. Fructans, a fermentable carb that often comes in the same foods as gluten, made symptoms worse. Gluten did no worse than the placebo.

What Researchers Suspect

If celiac genuinely increased, something in our environment changed, because genes can’t shift that fast. About 25 to 35% of people carry the genes that make celiac possible, yet only around 3% of those carriers ever develop it. The genes load the gun. Researchers are still working out what pulls the trigger.

Early-childhood infections are the strongest lead so far. In the TEDDY study, which follows thousands of genetically at-risk children in the US and Europe, a stomach infection raised the risk of celiac autoimmunity over the next three months by about a third. And children in Russian Karelia, who share part of their ancestry with Finns and eat similar grains, had confirmed celiac less than a quarter as often as children in neighboring Finland.

The amount of gluten in early childhood is the other suspect. A 2019 TEDDY analysis in JAMA of 6,605 at-risk children linked each extra daily gram of gluten before age 5 to a higher risk of celiac disease. It is observational, it only covers high-risk kids, and the authors call for a trial before anyone changes feeding advice.

Our guide to introducing gluten when celiac runs in the family walks through what that means in practice.

Where the Evidence Is Weak

The most popular explanation online is that modern wheat was bred into something more toxic. It is also the one with the least support. A USDA chemist’s review in 2013 found no clear evidence that the gluten content of US wheat rose during the 20th century. When German researchers grew 60 wheat varieties registered between 1891 and 2010 side by side, total gluten was unchanged.

The timing doesn’t fit either. Per-person US flour use peaked at 146.8 pounds in 1997 and has fallen since, to an estimated 126.6 pounds in 2025, while celiac diagnoses kept climbing. The one real change Kasarda found was added vital wheat gluten in processed food, which roughly tripled after 1977. Even he called its role “difficult to say,” since it is small next to the gluten we get from flour.

The rest of the usual suspects are weaker still. The glyphosate theory comes from a 2013 hypothesis paper with no original data, and we could not find a single epidemiological study linking the weedkiller to celiac. Blaming GMO wheat runs into a simple fact: no genetically engineered wheat is commercially grown in the US.

Food additives and ultra-processed food are plausible ideas, but we found no human study linking them to celiac. Childhood antibiotics are associated with later diagnoses, though the link is strongest in people whose biopsies were normal. That pattern points to more testing among people who see doctors more often, not to the drugs causing celiac.

What This Means If You’re Wondering About Gluten

None of this history changes what you should do today, but it does clarify it. Celiac is common, often hidden, and serious. A trend is not a diagnosis, in either direction.

Get tested before you change anything. The NIDDK says doctors don’t recommend starting a gluten-free diet before testing, because the diet can affect the results. The usual first step is a tTG-IgA blood test, and most adults then need a biopsy to confirm.

If celiac is ruled out and you still feel better without wheat, that is worth taking seriously too. Ask about FODMAPs, since fructans rather than gluten were the trigger in the Oslo trial, and work with a doctor or dietitian rather than guessing. Our undiagnosed celiac symptom checklist and our guide to reading your celiac blood work will help you prepare.

Mistakes People Make With the Gluten Headlines

• Quitting gluten “to see if it helps” — it may help, but it can also throw off celiac testing. Test first.
• Treating sensitivity and celiac as the same thing — celiac is an autoimmune disease in which gluten damages the small intestine, and small amounts count. Sensitivity has no test of its own and is diagnosed by ruling celiac out.
• Assuming ancient grains are safe — einkorn, emmer, spelt, farro and khorasan are all forms of wheat, and the Celiac Disease Foundation lists every one of them as a gluten source.
• Reading “contains wheat” as the whole story — US allergen labeling law covers wheat, not barley or rye. Malt is a gluten source too, and it usually comes from barley.
• Deciding celiac is a fad because gluten-free is trendy — the trend and the disease are separate stories, and the disease is the one with frozen blood samples behind it.
• Blaming yourself or your parents — randomized trials found that when babies first ate gluten, and whether they were breastfed, did not change their celiac risk.

Frequently Asked Questions

The Verdict on the ’90s

So why did nobody seem to have a gluten problem in the ’90s? They did. Celiac disease was common and mostly undiagnosed, and it has also become genuinely more common since the 1950s for reasons researchers are still pinning down. On top of that, a far larger group of people without celiac started avoiding gluten, and that is most of what you see in the grocery aisle.

The wheat didn’t turn on us. The evidence points to our environment, our tests and our culture changing around it. The most useful thing to take from all of this is simple: if gluten seems to be your problem, get tested before you quit it.

Something changed. Now you know what it was, and what to do about it.