When Not to Eat Fava Beans? Understanding the Risks

January 6, 2026 •

4 min read

According to the World Health Organization, an estimated 400 million people worldwide have glucose-6-phosphate dehydrogenase (G6PD) deficiency, a genetic condition that makes it extremely dangerous to eat fava beans. For those affected, understanding when not to eat fava beans is crucial for avoiding a life-threatening reaction.

Quick Summary

Fava beans should be avoided by individuals with G6PD deficiency due to the risk of hemolytic anemia, those on MAOI medications, people with digestive issues, and breastfeeding mothers.

Key Points

Favism is a Severe Risk: People with the genetic enzyme deficiency G6PD must never eat fava beans, as it can cause life-threatening hemolytic anemia.
Tyramine Interaction with MAOIs: Individuals on MAOI antidepressants must avoid fava beans due to the risk of a dangerous hypertensive crisis caused by tyramine.
Raw Beans are Dangerous: Raw fava beans contain toxins and are difficult to digest; they should always be cooked before eating to neutralize potentially harmful compounds.
Caution for Digestive Disorders: Those with conditions like IBS may experience significant bloating, gas, and cramps due to the bean's high fiber content.
Breastfeeding Mothers Need Caution: Nursing mothers should avoid fava beans if their infant has a G6PD deficiency, as compounds can pass through breast milk and harm the baby.
Proper Cooking is Essential: For those without health restrictions, cooking fava beans properly by blanching and peeling them can improve digestibility and safety.

G6PD Deficiency: The Primary Reason to Avoid Fava Beans

The most critical reason for certain individuals to avoid fava beans is a genetic condition known as Glucose-6-phosphate dehydrogenase (G6PD) deficiency. This inherited enzyme deficiency affects red blood cells and can be triggered by specific substances found in fava beans, leading to a serious and potentially fatal condition called favism.

What is G6PD Deficiency and Favism?

G6PD is an enzyme that helps protect red blood cells from oxidative damage. In people with a deficiency, red blood cells are vulnerable to destruction when exposed to certain triggers, such as the compounds vicine and convicine present in fava beans. This rapid breakdown of red blood cells causes hemolytic anemia, the hallmark of favism. Symptoms can include jaundice (yellowing skin and eyes), dark urine, fatigue, and fever. In severe cases, it can lead to kidney failure and death. G6PD deficiency is more common in people of African, Mediterranean, Middle Eastern, and Southeast Asian descent, and affects males more frequently than females. Even inhaling fava bean pollen can trigger a reaction in susceptible individuals.

Fava Beans and MAOI Medications

Another major cautionary scenario involves individuals taking Monoamine Oxidase Inhibitor (MAOI) medications. MAOIs are a class of antidepressants and are also used to treat Parkinson's disease.

Tyramine Interaction

Fava beans, especially the pods, contain a high level of tyramine, a naturally occurring amino acid. While the body can normally process tyramine, MAOI medications inhibit the enzyme (monoamine oxidase) responsible for this process. When tyramine builds up, it can cause a sudden and dangerous spike in blood pressure known as a hypertensive crisis. This can lead to symptoms like severe headache, chest pain, and a rapid heart rate. Anyone prescribed an MAOI should receive a list of dietary restrictions and must strictly avoid fava beans and other tyramine-rich foods. The risk persists for up to two weeks after discontinuing the medication.

Other Health Considerations

Digestive Disorders

For some people, fava beans can be a digestive irritant. The high fiber content and specific carbohydrate types can ferment in the gut, causing gas, bloating, stomach cramps, and diarrhea, particularly in individuals with pre-existing digestive disorders like irritable bowel syndrome (IBS) or Crohn's disease. While not as life-threatening as favism, these symptoms can cause significant discomfort.

Breastfeeding

If a mother has an infant with a G6PD deficiency, she must avoid fava beans, even if she does not have the condition herself. The oxidative compounds (vicine and convicine) can be transferred through breast milk to the infant, triggering a hemolytic crisis. There have been documented cases where severe complications, including renal failure and death, occurred in infants after maternal consumption of fava beans.

Avoiding Raw Fava Beans

Raw fava beans contain anti-nutrients and other compounds that can cause gastrointestinal upset and are difficult to digest. Cooking the beans, which often involves boiling and peeling, helps neutralize these compounds, making them much safer to eat for those without G6PD deficiency.

Comparison of Fava Bean Risks


Risk Factor	Primary Cause	Symptoms	Severity	Affected Population
Favism (G6PD Deficiency)	Inherited enzyme deficiency triggered by vicine and convicine	Hemolytic anemia, jaundice, dark urine, fatigue, fever	Critical and potentially fatal	Individuals with G6PD deficiency (often of Mediterranean, African, or Middle Eastern descent)
MAOI Interaction	High tyramine content interacting with MAOI medications	Hypertensive crisis, severe headache, increased heart rate, chest pain	Critical and potentially fatal	People taking MAOI antidepressants or Parkinson's medication
Digestive Sensitivity	High fiber content and specific carbs causing fermentation	Gas, bloating, stomach cramps, diarrhea	Mild to moderate, non-life-threatening discomfort	Individuals with sensitive stomachs or digestive disorders like IBS
Breastfeeding Concerns	Compounds passing through breast milk to a G6PD-deficient infant	Hemolytic crisis, jaundice, severe illness in infant	Critical for the infant	Breastfeeding mothers of G6PD-deficient infants

The Safest Approach to Fava Beans

For the vast majority of people, fava beans are a safe and nutritious part of a balanced diet when properly cooked. The key is to be aware of your personal health profile and any potential risks. If you have a family history of G6PD deficiency, are taking an MAOI, or have a chronic digestive condition, it is best to consult with a healthcare provider before introducing them into your diet. For those who can safely enjoy them, cooking the beans thoroughly helps to break down antinutrients and improve digestibility. VeganHealth.org offers additional details on the risks associated with G6PD deficiency.

Conclusion

While a delicious and popular legume in many cuisines, fava beans are not suitable for everyone. The most severe and potentially fatal risks are associated with G6PD deficiency and interactions with MAOI medications. Digestive sensitivity, raw consumption, and considerations for breastfeeding mothers also warrant caution. Prioritizing health by understanding and avoiding these specific risks is essential, ensuring fava beans are enjoyed safely by those who can tolerate them.

Frequently Asked Questions

Favism is a severe and potentially fatal condition triggered by consuming fava beans in individuals with a genetic enzyme deficiency called G6PD deficiency. The at-risk population includes people of Mediterranean, African, Middle Eastern, and Southeast Asian descent, with a higher prevalence in males.

Fava beans contain tyramine, and MAOI drugs interfere with the body's ability to process it. This can lead to a sudden and dangerous rise in blood pressure known as a hypertensive crisis.

Individuals with sensitive digestive systems or conditions like IBS may experience significant gastrointestinal discomfort, including gas, bloating, and cramps, due to the high fiber and carbohydrate content in fava beans.

No, if your infant has a G6PD deficiency, you must not consume fava beans. The problematic compounds can transfer to the baby through breast milk and trigger a severe hemolytic reaction.

No, raw fava beans contain natural toxins and anti-nutrients that can cause illness and are difficult to digest. They should always be cooked thoroughly to neutralize these compounds.

G6PD deficiency can be diagnosed with a simple blood test. If you have symptoms after eating fava beans or have a family history of the condition, you should consult a doctor.

Yes, all varieties of fava beans (broad beans) contain the compounds (vicine and convicine) that can trigger a reaction in individuals with G6PD deficiency. Cooking does not remove these compounds.