woman rejecting slices of bread

Gluten-free foods are consumed by as many as 100 million Americans, according to a 2015 review in Gastroenterology. But is cutting out gluten (a protein found in wheat, rye, and barley) a smart health move, or is it just a passing health food trend?

For individuals with a wheat allergy, giving up gluten is necessary. Reactions to gluten can include hives, nausea, vomiting, nasal problems, and even life-threatening anaphylaxis. For the 0.71 percent of the U.S. population with celiac disease, giving up gluten is also mandatory, although the signs can be varied and subtle. Celiac disease is a serious autoimmune condition in which the immune system attacks the lining of the intestines when gluten is consumed.

About 1 to 3 percent of Americans may have non-celiac gluten sensitivity (NCGS), a condition in which they experience a variety of symptoms when eating gluten, but their immune system doesn’t damage the intestinal wall as a result, according to Harvard Health. The exact cause and mechanism of NCGS is unknown. Additionally, some individuals have difficulty digesting fructans (sugars found in wheat and a few other foods), leading to a variety of gastrointestinal complaints (via Healthline). Although fructans and gluten are very different, cutting out gluten can often improve symptoms because fructan intake is dramatically decreased. Wondering if you should give up gluten? If you are experiencing any of the signs below, you may want to think about it.

Diarrhea can be a sign of gluten intolerance

scrap of toilet paper on the roll

Everyone experiences a bout of diarrhea from time to time, but if you’re experiencing chronic diarrhea, it may be a sign you need to go gluten free. Chronic diarrhea is often seen in those with celiac disease. It’s considered one of the hallmark symptoms of the "classical," or textbook, presentation of the condition (via Celiac Disease Foundation). Individuals may also have pale, fatty, or particularly foul-smelling stool.

These bathroom issues are the result of damage to the lining of the intestines, which means food can’t be properly digested and absorbed as it makes its way through the GI tract. Frequent diarrhea is also a symptom of non-celiac gluten sensitivity (NCGS). In a 2014 study of nearly 500 individuals with NCGS, over half complained of diarrhea.

It’s important to remember, however, that many conditions can cause chronic diarrhea. These include irritable bowel syndrome, inflammatory bowel disease (a group of autoimmune conditions), diabetes, an overactive thyroid, and an allergy or sensitivity to another food ingredient besides gluten. Certain medications, dietary supplements, and herbs can also cause chronic diarrhea (via UpToDate).

Bloating can be a sign to cut back on gluten

woman holding bloated stomach

You may need to kick your gluten habit if you’re frequently experiencing bloating. For those with celiac disease, it is one of the most common gastrointestinal complaints. According to a study published in Digestive Diseases and Sciences, of the 1,032 celiacs surveyed, 73 percent experienced bloating and gas. Bloating is also frequently seen in individuals with non-celiac gluten sensitivity. A 2014 study found that 87 percent of respondents experienced bloating. In fact, bloating was the most commonly reported symptom, gastrointestinal or otherwise.

As with other GI complaints, bloating is pretty nonspecific and can be caused by a number of conditions — some minor, some serious. As Healthline noted, bloat may simply be the result of excess gas or air in the digestive tract. This can be from chewing gum or eating or drinking too quickly and swallowing excess air.

Irritable bowel syndrome, inflammatory bowel disease, heartburn, hormone changes, and even stress or anxiety can also cause bloating. These conditions affect the gut in a variety of ways that promote bloating, including deficiency or overgrowth of certain bacteria, structural issues that lead to gas accumulation, and problems with how the muscles of the digestive tract function.

You could lessen abdominal pain by giving up gluten

woman with abdominal pain

Abdominal pain is a frequent complaint among people who cannot tolerate gluten well. It’s a common symptom among individuals with celiac disease, especially the "non-classical" presentation (via Celiac Disease Foundation). In a 2014 study of almost 500 Italian individuals with non-celiac gluten sensitivity, 83 percent complained of abdominal pain, making it the second most frequently reported symptom. In addition, 52 percent experienced epigastric pain (discomfort in the upper abdomen, where the ribcage divides).

Even individuals with irritable bowel syndrome may experience abdominal pain when they eat gluten. In a 2011 study published in The American Journal of Gastroenterology, researchers tracked the symptoms of non-celiac patients already on a gluten-free diet who consumed either gluten or a placebo. Rates of abdominal pain were higher among the gluten group after only one week.

The good news is that, for at least some individuals, going gluten free really does appear to help with abdominal pain. In a 2004 study, researchers tracked the gastrointestinal symptoms of 215 celiac patients after they embarked on a gluten-free diet. They found that "most patients had abdominal pain and bloating, which resolved with the diet."

Anemia can be a sign to go gluten free

loaves of bread

Iron-deficiency anemia is extremely common, affecting 20 percent of non-pregnant women, 50 percent of pregnant women, and 3 percent of men (via WebMD). Its prevalence may be even higher among individuals with celiac disease or non-celiac gluten sensitivity (NCGS). Among those with NCGS, approximately 22 percent experience anemia, per a 2014 study published in BMC Medicine.

According to Beyond Celiac, anemia is particularly common in people undiagnosed celiac disease because the part of the small intestine where iron is absorbed is also the area damaged by the immune system when gluten is consumed. The connection between anemia and celiac is so strong that unexplained anemia is often the symptom that triggers an initial test for celiac. In a Digestive Diseases and Sciences study of more than 1,000 celiacs, 63 percent had anemia.

The good news, as Beyond Celiac explained, is that anemia usually substantially improves on a strict gluten-free diet, though it may take a few months to see results. Without gluten triggering the immune system to attack, the intestinal lining has a chance to heal, making iron absorption easier.

Unexplained weight loss can be a reason to cut back on gluten

woman examining weight loss in mirror

Some people choose to go gluten free because they think it will lead to weight loss. But, according to the Cleveland Clinic, "there’s absolutely no evidence that simply getting rid of gluten will result in weight loss." In fact, eating gluten when you’re sensitive to it may cause weight loss, but not the kind you want.

Because damage to the intestinal lining can cause malabsorption of nutrients and chronic diarrhea, many undiagnosed celiacs are malnourished and underweight (via Mayo Clinic). Those with non-celiac gluten sensitivity (NCGS) may also be affected, even though their intestinal lining isn’t damaged. A 2014 study published in BMC Medicine found that 25 percent of individuals with NCGS experienced weight loss. So if you find yourself unintentionally losing weight or unable to put on weight, you may want to get screened for celiac disease or NCGS.

It’s important to note, however, that not all those with celiac disease are underweight. The University of Chicago’s Celiac Disease Center released a report that revealed that 22 to 32 percent of individuals with celiac are overweight or obese at time of diagnosis.

Weakening bones can be a sign to reduce your gluten intake

woman holding hip

According to Beyond Celiac, as many as 75 percent of individuals with newly diagnosed celiac disease have either osteoporosis or osteopenia. Osteoporosis is a "disease characterized by low bone mass and weakening of bone tissue that causes bones to become brittle and more likely to break," the organization explained. It can lead to back and hip pain, poor posture, and fractures. With osteopenia, bone mass is also lower than normal, but not yet severe enough to be considered osteoporosis.

Researchers believe that celiacs are at higher risk for low bone mass because of the malabsorption of nutrients and chronic inflammation characteristic of the condition. Specifically, trouble absorbing adequate amounts of calcium, vitamin D, and magnesium can negatively impact bone health. Although bone density usually improves on a gluten-free diet, Beyond Celiac noted that calcium and vitamin D supplements may still be needed.

The National Osteoporosis Foundation estimates that 10 million Americans have osteoporosis, while 44 million have osteopenia. The risk of low bone mass increases with age, but it can affect people of any age. If you’ve been diagnosed with either osteopenia or osteoporosis — especially if you’re under 50 — you should consider getting screened for celiac disease.

Joint pain can be a sign of gluten intolerance

man holding knee

Is gluten making you stiff and creaky? In a 2014 study published in BMC Medicine of individuals with non-celiac gluten sensitivity, 31 percent reported frequent joint or muscle pain when consuming gluten. The connection may be even more significant for people with celiac disease.

Citing a study conducted in Italy, Beyond Celiac noted, "Celiac disease patients are four times more likely to have early signs of arthritis in the lower limbs than the general public." Roughly 50 percent of newly diagnosed celiacs have enthesitis (inflammation of connective tissues like ligaments and tendons), compared to only 27 percent of celiacs on a gluten-free diet. The Achilles tendon and kneecap are the areas most likely to be affected.

According to the Centers for Disease Control and Prevention, 23 percent of all Americans have some form of arthritis. While we often think of arthritis as affecting only the elderly, 60 percent of people with arthritis are adults younger than 65. Although osteoarthritis (degeneration of the joint cartilage) is the most common form of arthritis, there are dozens of others, including rheumatoid arthritis, which is autoimmune condition. And, as Beyond Celiac explained, individuals with celiac disease are more likely to have other autoimmune conditions.

If eating gluten leads to headaches, it’s time to cut back

man with headache

Everyone has a headache from time to time, and even migraines are relatively common, affecting 39 million Americans. But if your head consistently hurts after eating a gluten-heavy meal, it may be a sign you have an intolerance. A study of individuals with non-celiac gluten sensitivity (NCGS) published in BMC Medicine in 2014 found that 54 percent of participants had frequent headaches when eating a gluten-containing diet.

According to Beyond Celiac, many people with celiac disease report migraines after consuming gluten. In addition, "some people with celiac disease find relief from migraines — such as how often they get migraines, the severity of the pain or how long they last — after beginning a strict gluten-free diet." The organization noted that although some research has indicated that migraine sufferers are more likely to have celiac disease, the connection is controversial and not universally accepted.

A paper published in Current Pain and Headache Reports in 2012 hypothesized that those with celiac disease and NCGS are more likely to experience headaches and migraines because their nervous systems are "hypervigilant." Because the body is constantly being triggered when gluten is consumed, the nervous system can become overreactive, making migraine attacks more likely.

Constant exhaustion can be a result of eating gluten

tired woman with head on desk

There are practically a million things that could be contributing to your chronic fatigue, but gluten is one that might not be on your radar. Even though it’s a very nonspecific symptom, tiredness is extremely common among individuals who cannot tolerate gluten.

In a 2014 study of individuals with non-celiac gluten sensitivity, 64 percent of respondents experienced tiredness when eating a gluten-containing diet, making it the second most common non-GI symptom. A study of celiac patients published in Digestive Diseases and Sciences found that fatigue was the most commonly reported symptom, affecting 82 percent of participants.

Since feeling fatigued is so common in our hectic modern lives, how can you tell if yours is related to gluten or not? As Beyond Celiac explained, "While fatigue may be a natural and transient part of life, in a chronic condition such as celiac disease, these symptoms are unrelieved by adequate sleep or rest." The organization noted that while feelings of exhaustion can improve once individuals with celiac begin a gluten-free diet, this isn’t always the case. Fatigue may be a secondary symptom of the malabsorption often seen in celiacs (via Verywell Health). Inability to properly absorb nutrients can lead to malnutrition and anemia, both of which can cause fatigue.

You may need to cut back on gluten if you develop an itchy, bumpy rash

dermatitis herpetiformis on woman's leg

Some individuals with celiac disease have a distinct skin condition known as dermatitis herpetiformis (DH). As Beyond Celiac explained, DH is sometimes known as celiac rash or gluten rash because only individuals with celiac disease get it. But not everyone with celiac disease will experience the condition, which is marked by extremely itchy and blistering skin.

DH affects only about 15 to 25 percent of celiacs and is more common in men than women. It appears most often on the knees, elbows, and buttocks. Since only 20 percent of individuals with DH have the telltale GI symptoms usually associated with celiac, this skin rash is sometimes the first clue that there’s an issue. Although sticking to a strict gluten-free diet can eventually resolve the rash, it may take up to two years.

Although DH is unique to celiac disease, people with non-celiac gluten sensitivity may also experience skin issues when they eat gluten. According to a 2014 study published in BMC Medicine, 29 percent of participants had a skin rash and 18 percent had dermatitis (an umbrella term for skin irritation).

Could gluten have something to do with infertility?

woman holding pregnancy test

Although it’s a topic that’s sadly often shrouded in secrecy, infertility is quite common. According to the National Institutes of Health, infertility — defined as the inability to conceive after one year of trying — affects approximately 11 percent of women and 9 percent of men. While there are many causes of infertility, if you have celiac disease, consuming gluten may be negatively impacting your reproductive health.

Beyond Celiac noted that some research has indicated a link between undiagnosed celiac disease and fertility issues in both women and men, though other studies haven’t found a connection. In one study, according to the organization, researchers found that "in the two years prior to celiac disease diagnosis, women … become pregnant less often, with 25 fewer pregnancies per 1,000."

Not being on a gluten-free diet when you have celiac disease has also been linked to increased risk for miscarriage, stillbirth, and preterm delivery. It’s unclear, however, if fertility problems in people with the disease stem from issues with the immune system or from nutritional deficiencies due to malabsorption. According to Beyond Celiac, people with non-celiac gluten sensitivity are also likely to be at increased risk for fertility issues. The organization suggests that anyone with unexplained infertility be screened for celiac disease.

Anxiety and depression can go hand in hand with gluten intolerance

anxious and depressed woman

For some individuals, eating gluten can negatively affect psychological well-being just as much as it can impact physical health. According to Beyond Celiac, it’s unclear if anxiety that emerges before someone is diagnosed with celiac disease is related to gluten consumption or not, but many celiacs report reduced symptoms once they begin a gluten-free diet. But worrying about accidentally consuming gluten or cross-contaminated foods can create post-diagnosis anxiety for some celiac patients.

People with celiac disease are also 1.8 times more likely to experience depression (via Beyond Celiac). There are several theories for why this may occur. First, malabsorption of nutrients because of a damaged intestinal lining may impair brain function. The damaged intestines may also allow more substances to pass directly into the bloodstream, and some of these may negatively affect the brain.

Even after diagnosis, individuals may become depressed because sticking to a strict gluten-free diet can require enormous dietary changes that can leave individuals feeling frustrated and deprived. Avoiding gluten can also create friction in social situations, such as eating out with friends, and may cause someone to feel lonely, misunderstood, or unsupported. Research suggests that approximately 39 percent of individuals with non-celiac gluten sensitivity have anxiety, while 18 percent experience depression.

Eating gluten can lead to brain fog

man with brain fog

According to a 2019 article in Patient, "Brain fog is a general term for a set of symptoms affecting the cognitive processes. It isn’t a medical condition in itself, but rather occurs as common feature of other conditions." Brain fog can lead to issues with memory, information processing, concentration, higher-level thought, and speaking to or understanding others. There are many things that can cause brain fog, but if you can’t explain why your mind always feels muddled, you may want to see if going gluten free could help. After all, a 2014 study of individuals with non-celiac gluten sensitivity found that 38 percent of individuals experienced "foggy mind."

In a study published in Alimentary Pharmacology & Therapeutics, researchers administered a number of cognitive tests to celiac patients at regular intervals for a year following diagnosis. Individuals were tested on how well they could process information, and their spatial abilities, memory, motor function, and attention were analyzed. The study authors concluded that below-optimal cognitive performance in undiagnosed celiacs probably interferes with everyday tasks. They also found that "in newly diagnosed celiac disease, cognitive performance improves with adherence to the gluten-free diet in parallel to mucosal [intestinal] healing."

You may need to cut out gluten if you have another food sensitivity, allergy, or autoimmune disease

allergy skin prick test

In an interview with Allergic Living, Dr. Scott Sicherer, an allergist, explained that having one food allergy can put you at increased risk for additional allergies, either because your immune system is primed to overreact or because some foods are chemically very similar. If you have one grain allergy (e.g., wheat allergy) you have a 20 percent increased risk of being allergic to another grain.

Those with non-celiac gluten sensitivity (NCGS) may also be at increased risk for other health problems. According to one 2014 study in BMC Medicine, 47 percent of NCGS individuals had irritable bowel syndrome, 35 percent had another food intolerance, 22 percent had an allergy, and 14 percent had an autoimmune disorder. Because celiac disease is an autoimmune condition, individuals with the disease are more likely to have other autoimmune conditions like type 1 diabetes or multiple sclerosis (via Celiac Disease Foundation).

Risk tends to increase with age of diagnosis. For instance, children diagnosed before age 4 have a 10.5 percent chance, while those diagnosed after age 20 have a 34 percent chance. Note: These connections are two-way streets. So if you’ve already been diagnosed with a food allergy or sensitivity or an autoimmune disease, you’re more likely than the average Joe to have issues with gluten.