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Decades ago, I ate a bagel at noon sitting in the sun in my backyard. I woke up three hours later with a fierce sunburn. There was no good reason for me to be so sleepy.

Soon, I realized that bagels and pasta often made me groggy, but I’d still eat wheat products occasionally.

More than 10 years ago, when I was getting attacks of intestinal cramps and diarrhea, my doctor told me to avoid gluten. I didn’t even know what “gluten” was then.

Now gluten-free products are everywhere.

But why would so many give up the ordinary versions of favorite foods, like hamburger buns and birthday cake?

For some, it’s just an experiment. But many others, like me, have found the switch helps relieve a surprising range of symptoms, from digestive issues to chronic stubborn ailments like fatigue, headaches, muscle aches, and anxiety.

The health of your gut affects your entire body. For some people, gluten can trigger inflammation anywhere — and they feel it.

“If you have inflammation of the brain, you can have anxiety,” Dr. Alessio Fasano, founder of Massachusetts General Hospital’s Center for Celiac Research and Treatment, told Healthline.

But simply giving up gluten may not be the right way to address your underlying problem.

“You can’t just throw darts,” said Dr. Leo Galland, a New York-based internist who specializes in nutritional approaches to gut healing. He explains that people need an organized approach to identify foods that bother them and eliminate other reasons for their symptoms.

The bottom line: Don’t do this alone. Work with a gastroenterologist or internist who’s knowledgeable about gluten problems. If your doctor dismisses your concerns, persist or find someone else.

4 reasons why you may feel better going gluten-free

  1. About of Americans have celiac disease. It’s an autoimmune response that causes gluten to trigger your body to attack your own intestinal walls. (Organizations like are a great resource for those who have this serious condition, or just want to learn more about it.)
  2. Some may have “non-celiac gluten sensitivity.” One theory is that they may have an “” immune response to gluten, which Fasano describes in detail in his book, “.” Although your body is treating gluten as an enemy, this reaction isn’t measurable like an allergy or autoimmune response.
  3. It might be FODMAPs. You might feel better on a gluten-free diet even if you don’t have any immune response to gluten. Instead, you may have a nonimmune reaction to a group of common carbohydrates called fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), which trigger irritable bowel syndrome. Wheat is one of them, so going off it helps you feel better.
  4. You might have a wheat allergy. Although very rare, it can potentially cause a range of allergy symptoms, including anaphylactic shock.

Once your gut is in trouble, it’s also common to develop issues with other foods, often dairy and soy. People with celiac or non-celiac gluten sensitivity may have to avoid other FODMAPs, too.

In short, the possible causes of your problems imply different treatments, and they also overlap.

You may have another problem

There’s no test for the innate immune reaction that may cause non-celiac gluten sensitivity.

And you may have a problem that isn’t specific to gluten. One smaller study found of people without celiac disease but who ate a gluten-free diet ended up receiving diagnoses other than celiac disease, such as small intestinal bacterial overgrowth.

Other possibilities were fructose and lactose intolerance, microscopic colitis, gastroparesis, and pelvic floor weakness.

“Each of those has its own therapy,” Dr. Benjamin Lebwohl, a gastroenterologist and researcher at Columbia University’s Celiac Disease Center and co-author of the book “Celiac Disease: An Issue of Gastrointestinal Endoscopy Clinics,” told Healthline.

Like many people who avoid gluten, I’ve received a diagnosis of irritable bowel syndrome (IBS), which affects around of people in North America. The standard treatment for IBS is to restrict high-FODMAP foods and perhaps take medication.

A small with people who weren’t celiac sensitive but considered themselves intolerant to gluten found that only 8 percent were really reacting to gluten. However, they all did better when they cut out FODMAPs.

Other found that the offender was most likely fructan, a subgroup of FODMAPs. Wheat and rye contain fructan, and so do a host of healthy vegetables, like broccoli, Brussels sprouts, cabbage, garlic, onion, artichoke, asparagus, and okra.

“There are certain red flags that make me focus on FODMAPs,” Galland said, noting these include bad reactions to apples, garlic, onions, artificial sweeteners, high fructose corn syrup, and wheat.

If you feel better without gluten but still have symptoms like bloating and diarrhea, check out a list of and see which may be affecting you. There are some simple moves that could help, like switching from tea to coffee and from apples and pears to blueberries and cantaloupe.

However, avoiding FODMAPs entirely isn’t a long-term diet, Lebwohl notes. You might work with a dietician to cut out these foods and then “cautiously reintroduce foods to identify triggers,” he says.

Seasonal allergies can complicate food sensitivities

I usually don’t pay attention to FODMAPs because I already don’t eat wheat, corn, or dairy, and I didn’t want to cut out tea or any vegetables. I also have high blood sugar, and a varied, plant-based . (In general, eating a greater variety of fruits and vegetables is good for your gut.)

However, this spring I paid the price. For several days while on a writing retreat, I had tea every morning and afternoon and ate big bowls of cooked Brussels sprouts or broccoli with avocado and hummus — all high-FODMAP foods. I ended up in full digestive distress, exhausted and anxious with aching muscles, and barely wrote at all.

I had picked the wrong time. “You can get GI [gastrointestinal] symptoms from seasonal allergies,” Galland explained, noting that mucus leaks into your digestive tract.

Celiac disease can cause permenant damage if it isn’t treated properly

Many people go off gluten and aren’t checked for celiac disease. The thought that you might have it may never cross your mind. But it’s not uncommon for people with celiac disease to puzzle the doctors who see them when their symptoms first show up.

In his mid-40s, Dr. Chad Shaffer was putting in 100-hour weeks as a chief medical officer and professor of medicine in Kansas City. Then suddenly, over a three-month period, he began losing weight and control of his muscles. He went from crutches to a wheelchair. After he developed a heart arrhythmia, he had an episode of cardiac arrest.

“We thought I had a terminal illness,” Shaffer said. Celiac was just one of many blood tests. It turned up positive. After an examination of his gut showed significant damage, he went off gluten.

But he didn’t get entirely better and was forced to retire.

Celiac is a serious illness that needs to be monitored over time. You’ll need to be 100 percent gluten-free for the rest of your life. Although your intestinal walls should heal once you stop eating gluten, you’ll need an endoscopy to check.

If it hasn’t healed, you’re at a higher risk of developing several forms of cancer, including intestinal lymphoma and small bowel cancer.

In a , researchers concluded that people with undiagnosed celiac disease were more likely to develop osteoporosis, chronic fatigue, and thyroid problems.

The only way to identify if you have celiac disease is by testing for it. If you’ve already gone off gluten, you can do a blood test to check for two known celiac-sensitive genes. Not having either of these genes “rules out celiac [disease] with as much certainty as we have in medicine,” Lebwohl says.

If you have a positive result on the gene test and haven’t been eating gluten, you’ll have to undergo a “gluten challenge” — something many people resist.

Around of all people have a celiac-sensitive gene, but only a small fraction of that number develops celiac disease. However, the condition can develop later in life.

Why would the grain that built human civilization cause problems now?

Gluten sensitivity isn’t new, and Fasano argues that problems digesting wheat go back to its origins.

Nevertheless, illnesses need to be defined and publicized to identify those who’ve been living with them. American doctors are becoming more aware of celiac disease and non-celiac immune responses. But there’s also that cases of undiagnosed celiac disease are increasing, although the causes haven’t been identified yet.

Today, we’re eating more wheat built into processed foods. Modern wheat contains more of certain proteins that are known to cause distress in mice with allergies and autoimmune issues.

Significant , antibiotics, infections, and other factors may make you more vulnerable as well.

Identifying the problem and making smarter choices

When making dietary changes to test for food sensitivities, it’s important to remember the same strategies don’t work for everyone. Our microbial inhabitants, which determine our gut health, vary from one person to the next. Your microbiome may even be

Any major changes to your diet should be done keeping that in mind. Work with your doctor to find the best solution that’s right for you.