Who should not eat buckwheat? A guide to diet and nutrition

November 3, 2025 •

5 min read

While most people safely enjoy this gluten-free pseudocereal, a study in Japan found buckwheat to be a frequent cause of food-related anaphylaxis, affecting some individuals severely. Knowing who should not eat buckwheat is crucial for those with specific health conditions or sensitivities to avoid adverse reactions.

Quick Summary

An overview of health concerns that require caution or avoidance of buckwheat. Key issues include potential allergies, high oxalate content, digestive sensitivities, and medication interactions. This resource outlines who needs to be mindful of this pseudocereal in their diet.

Key Points

Allergy risk: Individuals with buckwheat allergy, particularly those with existing latex or rice allergies, should avoid buckwheat due to the risk of severe reactions, including anaphylaxis.
Kidney stone history: The moderate oxalate content in buckwheat is a concern for people prone to kidney stones and should be discussed with a doctor.
Medication interactions: People with diabetes on blood sugar medication should consume buckwheat with caution due to its potential to lower blood sugar and interfere with treatment.
Digestive sensitivity: High fiber content can cause bloating or digestive issues, especially for those with sensitive digestive systems or those unaccustomed to high-fiber foods.
Pregnancy and breastfeeding: Due to insufficient research, large or medicinal amounts of buckwheat should be avoided during pregnancy and breastfeeding.
Cross-contamination: Those with celiac disease must ensure buckwheat products are certified gluten-free to avoid cross-contamination from shared processing facilities.

Buckwheat is often praised as a nutritious, gluten-free alternative to grains, celebrated for its fiber, magnesium, and protein content. However, despite its health benefits, not everyone can safely consume it. For some, buckwheat can trigger significant health issues, ranging from allergic reactions to digestive discomfort. Understanding these risks is key to a safe and healthy diet.

Who Should Not Eat Buckwheat? Key Considerations

Several specific groups of individuals need to be cautious with or completely avoid buckwheat. The reasons range from autoimmune responses to issues with how the body processes certain compounds found in the pseudocereal.

Buckwheat Allergies and Cross-Reactivity

Buckwheat is a known allergen, particularly in certain parts of Asia where its consumption is higher. An allergic reaction can be mild or, in serious cases, life-threatening.

Prevalence: Buckwheat allergy is a notable concern, especially in countries like Japan and Korea. High consumption increases the risk of sensitization.
Cross-Reactivity: Individuals with allergies to latex or rice may have a higher risk of developing a buckwheat allergy due to similar proteins. Some cases also show cross-reactivity with coconut and poppy seeds.
Sensitization: Exposure can occur not only through ingestion but also through inhalation of buckwheat flour, or even from contact with products like buckwheat-filled pillows.
Severe Reactions: Anaphylaxis, a severe and potentially fatal allergic reaction, has been reported in response to buckwheat consumption.

Symptoms of a buckwheat allergy can include:

Skin rashes, hives, or swelling of the mouth.
Respiratory issues such as wheezing, nasal congestion, or asthma.
Gastrointestinal problems like abdominal pain, nausea, or vomiting.
Anaphylaxis, characterized by breathing difficulties, a rapid pulse, or loss of consciousness.

High Oxalate Content and Kidney Health

Buckwheat contains moderate levels of oxalates, which can be problematic for susceptible individuals.

Risk of Kidney Stones: People with a history of calcium oxalate kidney stones should monitor their intake of high-oxalate foods. Excessive consumption could contribute to stone formation.
Consult a Doctor: If you have a known oxalate sensitivity or kidney issues, consulting a healthcare provider is essential before incorporating buckwheat into your daily diet.
Not for Everyone with Kidney Issues: While some studies point to buckwheat being beneficial for kidney health in some contexts, particularly for those with early-stage diabetic kidney disease, its moderate oxalate and potassium content requires careful consideration for all with compromised kidney function.

Digestive Sensitivities and High Fiber Intake

Buckwheat is a rich source of dietary fiber, which is generally beneficial but can cause problems for some people.

Bloating and Discomfort: Those unaccustomed to a high-fiber diet, or with underlying digestive issues, may experience bloating, gas, or general digestive discomfort if they eat too much buckwheat.
Processing Helps: Soaking raw buckwheat groats can make them easier to digest for some individuals.

Buckwheat and Diabetes Medication

Buckwheat has properties that can help regulate blood sugar, which is often a benefit for individuals with diabetes. However, this can become a concern for those on medication.

Hypoglycemia Risk: Because buckwheat can lower blood sugar levels, taking it in medicinal amounts or consuming large quantities while on diabetes medication could cause blood sugar to drop too low.
Careful Monitoring: Individuals with diabetes should monitor their blood sugar closely and consult their doctor about any potential adjustments to their medication. It is advised to stop using large amounts of buckwheat at least two weeks before scheduled surgery.

Comparison: Buckwheat, Quinoa, and Wheat

To better understand where buckwheat fits into a dietary plan, here's a comparison with two other common options.


Feature	Buckwheat	Quinoa	Wheat
Allergen Risk	Moderate; known allergen in some populations, especially in East Asia.	Low; generally considered hypoallergenic, though not entirely without risk.	High; contains gluten, a common allergen for celiac disease and gluten sensitivity.
Gluten-Free	Yes.	Yes.	No.
Oxalate Content	Moderate; caution needed for those with kidney stone history.	Moderate to high; rinsing is recommended to reduce content.	Low.
Digestive Impact	High fiber content can cause discomfort for some.	High fiber can be difficult for some to digest.	Can cause issues due to gluten for sensitive individuals.
Cross-Reactivity	Potential cross-reactivity with latex and rice.	Potential cross-reactivity with other foods is rare.	Potential cross-reactivity with other grains.

Other Considerations and Contraindications

Pregnancy and Breastfeeding

There is a lack of reliable research on the safety of using buckwheat medicinally during pregnancy and breastfeeding. It is best to avoid use in large quantities during these periods to stay on the safe side.

Phototoxicity (Fagopyrism)

Although rare in humans due to low fagopyrin levels in processed grains, consuming large amounts of certain buckwheat varieties (especially Tartary buckwheat) can potentially lead to skin photosensitivity, a condition called fagopyrism, if exposed to sunlight.

Cross-Contamination with Gluten

While naturally gluten-free, buckwheat products can be contaminated with gluten if processed in facilities that also handle wheat. This is a critical point for individuals with celiac disease or severe gluten sensitivity, who must seek certified gluten-free products to ensure safety.

Salicylate and Lectin Sensitivities

For those with salicylate sensitivity, buckwheat is generally considered a low-salicylate food. It contains a moderate amount of lectins, which can cause food intolerance symptoms in some people, though cooking helps reduce their impact.

When to Consult a Professional

Before making any significant changes to your diet, especially if you have pre-existing health conditions, it is important to consult a doctor or registered dietitian. They can provide personalized advice based on your health history and dietary needs. This is particularly vital for those with diabetes, kidney issues, or known food sensitivities. For suspected allergies, a consultation with an allergist is the safest course of action.

Conclusion

Buckwheat is a highly nutritious pseudocereal that is a healthy part of the diet for most people, especially as a gluten-free alternative. However, it is not suitable for everyone. Individuals with buckwheat allergies, those prone to calcium oxalate kidney stones, or those with sensitive digestive systems should exercise caution or avoid it entirely. Additionally, careful monitoring is needed for people with diabetes on medication. By understanding these potential risks and consulting healthcare professionals when necessary, you can make informed dietary choices for your health and well-being. For more information on managing food allergies, visit the Anaphylaxis UK website.

Frequently Asked Questions

Yes, a person with a wheat allergy can typically eat buckwheat. Despite its name, buckwheat is not related to wheat and is naturally gluten-free. However, cross-contamination with wheat can occur in processing facilities, so it's vital for those with severe allergies or celiac disease to choose certified gluten-free products.

Yes, buckwheat allergies are more common in places where buckwheat is a staple food, such as Japan and Korea. Regular, large-quantity consumption increases the likelihood of developing an allergy.

Yes, allergic reactions can be triggered by exposure to buckwheat flour through inhalation, a risk particularly for workers in mills or bakeries. In some cases, people have been sensitized by sleeping on pillows filled with buckwheat husks.

Symptoms of a buckwheat allergy can range from skin rashes, hives, and swelling to more severe reactions like respiratory distress (wheezing, asthma), digestive issues (vomiting, abdominal pain), and anaphylaxis.

People prone to kidney stones should be cautious with buckwheat because it contains moderate levels of oxalates, which can contribute to the formation of calcium oxalate kidney stones in susceptible individuals.

Yes, buckwheat can lower blood sugar levels. While this can be beneficial for some, it requires caution for people with diabetes who are taking medication to manage their blood sugar, as it could lead to hypoglycemia.

For some people, especially those with sensitive digestive systems or those who suddenly increase their intake, the high fiber content in buckwheat can cause digestive discomfort such as bloating or gas. Soaking the groats can help make them easier to digest.

Currently, there is not enough reliable information to confirm the safety of medicinal amounts of buckwheat during pregnancy and breastfeeding. For this reason, it is generally recommended to avoid it as a medicinal supplement during these periods.