What foods should you avoid with glucose 6 phosphate dehydrogenase deficiency?

January 4, 2026 •

4 min read

An estimated 400 million people worldwide are affected by glucose-6-phosphate dehydrogenase (G6PD) deficiency, a genetic condition that makes red blood cells vulnerable to oxidative damage. For these individuals, consuming specific foods can trigger a dangerous hemolytic crisis, making careful dietary management a critical aspect of their health.

Quick Summary

A dietary guide to managing glucose 6 phosphate dehydrogenase deficiency, detailing crucial food and supplement restrictions. The focus is on triggers that cause oxidative stress and subsequent red blood cell destruction, with special emphasis on fava beans and certain legumes.

Key Points

Avoid Fava Beans Absolutely: Fava beans and any products containing them are the most dangerous food item for G6PD deficient individuals due to the high levels of vicine and convicine.
Be Cautious with Other Legumes: Some people may react to other legumes like soy products, peas, lentils, and peanuts, so personal tolerance and caution are key.
Identify Oxidative Food Triggers: Oxidative agents are not just in legumes; they can be found in foods like bitter melon, blueberries, and additives like certain artificial dyes.
Watch for Supplement Side Effects: High doses of synthetic Vitamin C and all forms of synthetic Vitamin K (menadione) can trigger hemolysis and should be avoided.
Read All Labels Carefully: Naphthalene in mothballs and menthol in candies are common non-food triggers that can cause a reaction; checking ingredient lists is essential.
Embrace an Antioxidant-Rich Diet: A healthy diet focused on fruits, vegetables, whole grains, and lean proteins helps manage oxidative stress and is generally safe.

Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency have a genetic condition that reduces their red blood cells' ability to handle oxidative stress. The G6PD enzyme is vital for protecting red blood cells from damage caused by certain substances, known as oxidative agents. When these individuals are exposed to such agents, their red blood cells can break down prematurely, a process called hemolysis. This can lead to hemolytic anemia, which manifests as symptoms like fatigue, jaundice, and rapid heart rate. While G6PD deficiency is triggered by various factors, including infections and certain medications, diet plays a key role in management.

The Primary Culprit: Fava Beans

For those with G6PD deficiency, no food is more notoriously dangerous than the fava bean. This legume, also known as broad, windsor, or horse bean, contains the compounds vicine and convicine. When consumed, these compounds trigger a rapid and severe hemolytic reaction in susceptible individuals, a condition specifically named favism.

This reaction can be life-threatening and is not limited to just eating the beans. Exposure can also occur through inhaling the pollen of the fava bean plant. It is crucial for anyone with G6PD deficiency to completely eliminate fava beans and all products containing fava bean derivatives from their diet. This includes falafel and various plant-based meat substitutes that may use fava bean protein.

Other Legumes and Legume Derivatives

While fava beans are the most significant risk, other legumes have been noted as potential, though less certain, triggers for some G6PD deficient individuals. Recommendations can vary based on the severity of the individual's deficiency and their personal reactions. It is wise for patients to proceed with caution and discuss potential triggers with their doctor.

Legumes to Approach with Caution

Soy Products: Soya milk, tofu, and other soy-based foods have been reported as potential triggers.
Peas and Peanuts: Some sources list these as potential triggers for hemolysis.
Lentils and Chickpeas: Similar to peas and peanuts, some legumes like lentils and chickpeas are on some cautious-approach lists.
Fenugreek Seeds: These have also been mentioned as a possible trigger for some individuals.

Foods and Additives with Oxidative Properties

Beyond legumes, certain other foods and food additives can increase oxidative stress and should be avoided or consumed with extreme caution.

Supplements to Avoid

Certain vitamins and supplements, especially in large doses, should be avoided as they can increase oxidative stress.

Vitamin K Supplements: Specifically, synthetic forms like K3 (menadione) can be highly toxic to red blood cells in G6PD deficient individuals and have been linked to hemolysis.
High-Dose Ascorbic Acid (Vitamin C): Large doses of synthetic Vitamin C can also trigger hemolytic reactions.

Navigating Prescriptions and Supplements

For a comprehensive list of drugs to avoid, it is best to consult with a healthcare professional. You can also refer to the Italian G6PD Deficiency Association, referenced by NCBI, which publishes an extensive list.

Comparison Table: Trigger vs. Safe Foods


High-Risk Trigger Foods	Safer Food Choices
Fava Beans & Products (Falafel)	Whole Grains (Oats, Rice)
Soy & Some Legumes (Peas, Lentils)	Lean Proteins (Chicken, Fish)
Blueberries	Most Fruits (Apples, Oranges)
Bitter Melon/Gourd	Most Vegetables (Spinach, Carrots)
Quinine (Tonic Water)	Dairy Products (Milk, Yogurt)
Synthetic Vitamin K & High-dose C	Antioxidant-Rich Foods (Berries, Tomatoes)

Conclusion

While a diagnosis of glucose-6-phosphate dehydrogenase deficiency requires careful attention to diet, it does not mean sacrificing a nutritious and satisfying meal plan. The cornerstone of management is the absolute avoidance of fava beans and a cautious approach to other potential triggers like some legumes, certain food additives, and specific supplements. Focusing on a balanced diet rich in antioxidant-filled foods like fruits, vegetables, and whole grains is a positive and proactive strategy. Always read food labels carefully and communicate openly with healthcare providers to develop a personalized, safe dietary plan that minimizes the risk of hemolytic episodes.

For more detailed information on specific dietary restrictions and medication interactions, the Italian G6PD Deficiency Association is a valuable resource [www.g6pd.org/it].

Frequently Asked Questions

Fava beans are the most dangerous food for individuals with G6PD deficiency. They contain vicine and convicine, which can cause severe, life-threatening hemolytic anemia.

While generally less problematic than fava beans, other legumes like soy, peas, lentils, and chickpeas can be potential triggers for some individuals. Caution is advised, and personal tolerance can vary.

Certain foods, medications, and chemicals create oxidative stress in the body. Since G6PD helps protect red blood cells from this stress, a deficiency can lead to red blood cell breakdown (hemolysis) when exposed to these triggers.

Not all artificial colors are triggers, but some, particularly certain azo dyes and blue food colors, have been associated with hemolysis in some cases. It is safer to limit or avoid processed foods with numerous additives.

While small amounts of naturally occurring Vitamin C in fruits and vegetables are fine, high doses of synthetic ascorbic acid supplements should be avoided as they can trigger hemolysis in some individuals.

Products containing menthol, such as toothpaste, breath mints, and candies, have been listed as potential triggers and should be avoided to prevent adverse reactions.

A diet rich in antioxidant foods like fruits, vegetables, and whole grains is recommended. A Mediterranean-style diet is often cited as a safe and healthy pattern to follow.