Who should not eat nuts? The complete guide

November 1, 2025 •

4 min read

According to the Australasian Society of Clinical Immunology and Allergy (ASCIA), peanut and tree nut allergies affect up to 3% of children, making it crucial to understand who should not eat nuts. For many, nuts are a healthy snack, but for certain individuals, they pose significant health risks, from life-threatening allergies to digestive distress. This guide outlines the key reasons and groups that need to avoid nuts.

Quick Summary

This guide covers the key reasons certain individuals should avoid nuts, including severe allergies, digestive problems like IBS, and choking hazards for young children. It details the risks and provides actionable advice for those with dietary restrictions.

Key Points

Nut Allergy Sufferers: Anyone diagnosed with a nut allergy, which can trigger a life-threatening reaction called anaphylaxis, must completely avoid nuts.
Infants and Young Children (Under 5): Whole nuts are a serious choking hazard and should not be given to children under five years old.
Individuals with Digestive Issues: Those with conditions like IBS, gastritis, or colitis, or anyone with a sensitivity to high fiber and fats, should limit or avoid nuts to prevent discomfort like bloating and gas.
People with Kidney Concerns: Nuts high in oxalates, such as cashews and almonds, should be limited by individuals prone to kidney stones.
Those Taking Certain Medications: Nuts can interact with some medications. Always consult a doctor or dietitian, especially if taking blood pressure medication.
Individuals with Eosinophilic Esophagitis: Nuts can trigger symptoms in people with this chronic allergic inflammatory disease of the esophagus.

Nut Allergies: The Most Common and Severe Risk

Nut allergies are one of the most serious and widespread reasons to avoid nuts. An allergic reaction occurs when the immune system mistakenly identifies certain proteins in nuts as a harmful threat. This triggers a reaction that can range from mild symptoms to a severe, life-threatening condition called anaphylaxis.

Symptoms of a nut allergy

Symptoms can appear within minutes to an hour of exposure and can vary widely.

Mild to moderate symptoms: Hives or a red, bumpy rash; tingling or itching in the mouth; stomach pain, nausea, vomiting, or diarrhea; and swelling of the face, lips, or tongue.
Severe (anaphylactic) symptoms: Difficulty breathing or noisy breathing; a tight throat or hoarse voice; persistent cough or wheezing; feeling dizzy or fainting; and becoming pale and floppy (especially in young children).

Important: If you experience any signs of anaphylaxis, seek immediate medical attention by calling emergency services.

Digestive Issues and Intolerances

Beyond allergies, certain gastrointestinal (GI) conditions and intolerances can make eating nuts uncomfortable or harmful. These issues are not immune-system-related allergies but rather a problem with digestion.

High-fiber content

Nuts are high in fiber, which is generally a positive health benefit. However, for individuals not accustomed to high-fiber diets, or those with existing GI sensitivities, this can lead to bloating, gas, and stomach cramps. The key is moderation and a gradual increase in consumption, but some may need to avoid nuts entirely.

Anti-nutrients in nuts

Some nuts contain compounds like phytic acid and oxalates that can interfere with digestion and nutrient absorption.

Phytic acid: This compound can bind to minerals like zinc, calcium, and magnesium, making them harder for the body to absorb. Some digestive tracts are more sensitive to this effect than others.
Oxalates: Found in nuts like almonds and cashews, excessive intake of oxalates can irritate the gut and potentially contribute to kidney stones in susceptible individuals.

Conditions requiring caution

Specific digestive conditions can be aggravated by nuts:

Gastritis and colitis: The high fiber and fat content can irritate the digestive lining and worsen symptoms.
Irritable Bowel Syndrome (IBS): While individual triggers vary, nuts can be problematic for some IBS sufferers due to their fiber content and potential for causing gas and bloating.
GERD (Acid Reflux): The high fat content in nuts can cause the esophageal sphincter to relax, which can worsen reflux symptoms in some people. Opting for lower-fat nuts or reducing portion size may help, but avoidance might be necessary.

Choking Hazards, Especially for Children

For very young children, whole nuts pose a significant choking risk. Their airways are small, and they may not have the chewing ability to break down nuts properly, making them a serious danger.

Health authorities, including the NHS in the UK, advise against giving whole nuts to children under five years old.
Nut butters or ground nuts are safe for children from around six months, provided there is no family history of allergies.

Other Specific Health Conditions

Certain medical conditions or medication use may necessitate avoiding or limiting nut intake.

Kidney-Related Issues: Those with kidney stones or a history of them should limit nuts high in oxalates, such as almonds and cashews.
Medication Interactions: For example, almonds are high in manganese, and excessive consumption alongside certain medications, like blood pressure drugs, could cause interactions. It's always best to consult a doctor or dietitian regarding potential interactions.
Selenium Toxicity: An overconsumption of Brazil nuts can lead to selenium poisoning, causing symptoms like diarrhea, skin rashes, and fatigue. This is a rare but serious risk, and portion control is vital.

Comparison Table: Risks Associated with Common Nuts


Nut Type	Primary Risk Group	Specific Considerations
Peanuts	Nut Allergy Sufferers	Botanically legumes, but a very common and often severe allergen. High risk of cross-contamination.
Almonds	Nut Allergy Sufferers, Digestive Issues, Kidney Issues	High in fiber, oxalates, and manganese. Excessive intake can cause digestive upset and potential kidney problems.
Cashews	Nut Allergy Sufferers, Digestive Issues, Kidney Issues	High in oxalates. The shell contains urushiol, which can cause an allergic skin reaction, so only consume roasted or steamed varieties.
Brazil Nuts	Those at risk for selenium toxicity	Extremely high in selenium. Limiting to one or two per day is crucial to avoid overdose symptoms.
Walnuts	Nut Allergy Sufferers, Digestive Issues	High in fat and phytic acid. Can cause bloating and diarrhea if over-consumed.

Conclusion: Prioritize Safety Over Assumptions

While nuts are a nutrient-dense food for most, understanding who should not eat nuts is a critical aspect of health and safety. The most urgent concerns involve severe allergies, especially anaphylaxis, which necessitates total avoidance and emergency preparedness. Digestive intolerances, though less severe, can cause significant discomfort and require careful monitoring or dietary changes. For very young children, whole nuts are a mechanical hazard that can lead to choking. Anyone with underlying health conditions, such as kidney stones, or those taking specific medications should consult a healthcare provider to ensure nuts do not pose an additional risk. By staying informed and recognizing individual health needs, you can make safe and healthy dietary choices. The Royal Children's Hospital fact sheet on allergies provides additional detailed information on managing nut allergies.

Disclaimer: This information is for educational purposes only and should not be considered medical advice. Always consult a healthcare professional regarding specific health concerns or before making changes to your diet.

Frequently Asked Questions

Yes, a nut intolerance is often confused with an allergy. While an allergy is an immune system response that can be severe and immediate, an intolerance is a digestive issue, with delayed symptoms like bloating or gas.

Anaphylaxis is a severe, life-threatening allergic reaction that can be caused by nuts. It involves multi-system symptoms like breathing difficulties, a rapid drop in blood pressure, and swelling of the throat and tongue, requiring immediate emergency treatment.

No, botanically, peanuts are legumes, growing underground like beans and peas. However, many people with a peanut allergy are also allergic to tree nuts like walnuts, almonds, and cashews, and vice versa.

Yes, it is possible to be allergic to specific types of nuts and not all. An allergy specialist can determine which nuts should be avoided. However, in cases of severe allergies, it is often recommended to avoid all nuts due to cross-contamination risks.

No. The allergic proteins in nuts are generally resistant to heat and stomach acid. Whether raw, roasted, or cooked, they can still trigger a severe allergic reaction.

The high fat and fiber content in nuts can be difficult for some individuals to digest, leading to gas, bloating, and cramps, especially if consumed in large quantities. Naturally occurring compounds like phytic acid can also contribute to digestive distress.

Unlike some other allergies, nut allergies, especially peanut allergies, often persist throughout a person's life. While some children may outgrow certain food allergies, it's less common with nuts. Any changes should be monitored by an allergy specialist.