Attention deficit hyperactivity disorder (ADHD) is a neurological condition that can affect your ability to focus your attention and manage impulses, along with your energy levels.
This condition can affect people of any age, though it’s most often diagnosed in childhood. Although the condition is common, experts don’t fully understand what causes it, which has led to widespread speculation about potential contributing factors.
For instance, many people believe certain foods can cause ADHD, though scientific evidence doesn’t support this idea. Other theories link ADHD to celiac disease, a condition in which gluten exposure causes your immune system to attack your intestines.
According to this idea, the resulting gut inflammation and microbiome disruption could contribute to ADHD symptoms.
Read on for an in-depth exploration of the suggested connection between ADHD and celiac disease.
Some studies do point to higher rates of co-occurrence, but evidence for a link between ADHD and celiac disease remains fairly contradictory.
In a widely cited
Since healthcare professionals generally diagnose celiac disease with several tests, including a biopsy of intestinal tissue, other experts, such as the authors of a 2016 study, have questioned the accuracy of these findings. Plus, 67 participants is a very small number, in terms of scientific research.
For two of these participants, ADHD did seem to occur as an early sign of celiac disease. But since these participants were siblings, factors like genetics may have also played a part.
A 2020 review found evidence to link childhood celiac disease to an increased risk of developing psychiatric conditions, including ADHD, later in life.
Overall, much of the supporting evidence for a link remains fairly weak. The apparent overlap may, more than likely, stem from additional variables in play, such as having a family history of both conditions.
While celiac disease doesn’t cause ADHD, it may cause brain fog, which can make your thinking feel slow and fuzzy. Some people refer to this symptom as celiac fog or gluten-induced neurocognitive impairment (GINI).
The nonprofit Beyond Celiac recently helped conduct a national survey of 1,400 people with celiac disease or nonceliac gluten sensitivity. Researchers found that 89% of people with celiac disease reported brain fog symptoms.
That said, the participants all volunteered to complete the survey, so the true prevalence of brain fog may be lower, especially for people with mild, undiagnosed celiac disease.
The most common celiac fog symptoms included:
- difficulty concentrating, reported by 72% of participants
- forgetfulness, reported by 60% of participants
- grogginess, reported by 58% of participants
- feeling detached, reported by 47% of participants
- mental confusion, reported by 45% of participants
Celiac fog symptoms typically appear within an hour of exposure to gluten. The symptoms are often most severe during the first 24 hours after exposure, but some people continue to experience symptoms for up to 5 days after consuming gluten.
As you might notice from the list of symptoms, symptoms of celiac fog do resemble some of the main symptoms of ADHD. But celiac fog only appears after gluten exposure, whereas ADHD symptoms remain pretty constant throughout everyday life.
Plus, while removing gluten from your diet can help ease celiac fog, you’ll generally need therapy, medication, or a combination to improve ADHD symptoms.
Learn more about treatments for ADHD.
Why does celiac disease cause brain fog?
Experts don’t yet know exactly how an intestinal disorder can affect brain function and health.
Three main theories from 2016 research include:
- Malabsorption theory: Celiac disease may disrupt your digestion of certain nutrients, depriving your brain of the building blocks needed to produce the chemical messengers involved in attention and motivation.
- Inflammation theory: Inflammatory agents may travel beyond your intestine and mistakenly attack other parts of your nervous system.
- Leaky gut theory: Celiac disease may prompt your microbiome to make toxic byproducts that leak into your bloodstream and cross the blood-brain barrier.
Future research on the gut-brain axis may help researchers find a more conclusive explanation.
While most research doesn’t support a link between ADHD and celiac disease, evidence does suggest a strong link between ADHD and food allergies.
A 2022 study found that adolescents with food allergies had 4.5 times the risk of displaying “probable ADHD.”
Food allergies share a few symptoms with celiac disease, including:
- stomach cramps
If your ADHD symptoms worsen after, say, eating cake or cereal, that’s not necessarily proof you have celiac disease. You may instead have a wheat or dairy allergy that’s worsening your symptoms.
A doctor or allergy specialist can conduct allergy testing to help uncover the true source of your food sensitivities.
Some ADHD medications may cause side effects that resemble symptoms of celiac disease.
The Food and Drug Administration (FDA) has listed several gastrointestinal side effects for methylphenidate (Ritalin), including:
- unintended weight loss
- abdominal pain
Children taking Ritalin may have a notable loss of appetite, just as they do with celiac disease.
Since weight loss and reduced appetite could stunt long-term growth, it’s important to connect with a healthcare professional for more guidance if your child has no appetite or experiences digestive distress after eating.
If you have celiac disease, removing gluten from your diet can ease your brain fog symptoms, helping you feel more alert and focused. If you’re part of the small population that has both celiac disease and ADHD, treating brain fog may provide some relief from ADHD symptoms too.
But if you don’t have celiac disease or gluten intolerance, not much evidence supports a gluten-free diet for ADHD. The studies that have shown improvement in symptoms have generally been
According to a
Restricting gluten from your diet could, in fact, have a negative impact on your health. Some people who try a gluten-free diet without professional guidance simply cut bread and other gluten-containing foods without replacing the lost nutrients, which can cause deficiencies in:
People with ADHD
Vitamin B deficiency can prove especially concerning, since the lower your levels of vitamin B2 or B6, the more severe ADHD symptoms tend to get.
It’s always best to get guidance from a doctor or dietitian before making any major dietary changes for yourself or your child.
If you have celiac disease and require a gluten-free diet, a healthcare team can design a balanced meal plan that keeps your gut regulated without depriving your brain of nutrients.
Your diet does have some role in brain function and health, so the foods you eat could play a part in ADHD symptoms. But not all diets are equally effective.
An oligoantigenic diet is a diet that involves only a few foods. You may limit your food intake to a handful of hypoallergenic options, such as rice, turkey, or pears.
But researchers haven’t found enough evidence to recommend this as a general dietary plan for people with ADHD.
The evidence for removing food additives is a bit stronger. A
- artificial dyes and colorants
- artificial sweeteners
- artificial fragrances
- artificial preservatives
That said, these changes have also improved hyperactivity in kids without ADHD. It’s also possible this diet works by addressing underlying food sensitivities, rather than ADHD itself.
ADHD isn’t linked to unusually low levels of omega-3 fatty acids. But omega-3s strongly support brain health, and some
Even so, like the other diets mentioned above, the evidence for omega-3 supplementation remains far from conclusive.
A balanced diet
Barring any health issues, people with ADHD generally don’t need specialized diets. A balanced diet is often enough to support your mental health.
As noted above, many people with ADHD don’t get enough of certain vitamins and nutrients. It’s essential to get enough:
Vitamin supplements can help ensure you get enough nutrients each day. However, your body tends to absorb nutrients more easily when they come in actual food. Supplements can support a nutritious diet, but they shouldn’t replace it.
If you think you may need help meeting your nutritional needs, always check with a healthcare professional before trying supplements. They can offer more guidance on the type of supplement to take, along with dosage recommendations.
Little recent evidence supports a link between ADHD and celiac disease.
This suggested connection may partially relate to the fact that brain fog related to celiac disease may resemble ADHD symptoms. What’s more, ADHD often co-occurs with food allergies that can seem very similar to symptoms of celiac disease.
Avoiding gluten may be the go-to treatment for celiac disease, but gluten restriction likely won’t do much to improve ADHD. Keep in mind, too, that many people with ADHD don’t get enough of certain key nutrients, so restrictive diets may ultimately do more harm than good.
If you have both gut and mental health symptoms, a good next step involves connecting with a healthcare professional to get a diagnosis and explore your options for treatment.
Emily Swaim is a freelance health writer and editor who specializes in psychology. She has a BA in English from Kenyon College and an MFA in writing from California College of the Arts. In 2021, she received her Board of Editors in Life Sciences (BELS) certification. You can find more of her work on GoodTherapy, Verywell, Investopedia, Vox, and Insider. Find her on Twitter and LinkedIn.