Favism
What is Favism?
Favism is a genetic condition that causes a severe reaction when people with G6PD deficiency eat fava beans. G6PD stands for glucose-6-phosphate dehydrogenase, an enzyme that protects red blood cells from damage. When someone with G6PD deficiency eats fava beans, their red blood cells break apart rapidly. This process is called hemolysis.
The reaction can happen within hours of eating fava beans or foods made with them. Red blood cells release their contents into the bloodstream, which can lead to anemia. Anemia means your blood does not carry enough oxygen to your body. In severe cases, favism can cause kidney damage and requires immediate medical care.
Favism is most common in people of Mediterranean, African, Middle Eastern, and Asian descent. The condition affects millions of people worldwide. Most people with G6PD deficiency never know they have it until they eat fava beans or take certain medications. Once diagnosed, favism is manageable by avoiding fava beans and other triggers.
Symptoms
- Dark or cola-colored urine within hours of eating fava beans
- Yellowing of the skin and eyes, called jaundice
- Extreme tiredness and weakness
- Pale skin and lips
- Rapid heartbeat or heart pounding
- Shortness of breath or difficulty breathing
- Fever and chills
- Back pain or abdominal pain
- Dizziness or lightheadedness
- Enlarged spleen
Many people with G6PD deficiency have no symptoms until they are exposed to triggers like fava beans. Children often show more severe symptoms than adults. Symptoms typically appear 24 to 48 hours after eating fava beans. Some people experience symptoms within just a few hours of exposure.
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Causes and risk factors
Favism is caused by an inherited deficiency of the G6PD enzyme. This enzyme protects red blood cells from oxidative stress, which is damage from unstable molecules. Fava beans contain compounds called vicine and convicine that create oxidative stress. In people without enough G6PD enzyme, these compounds cause red blood cells to break down rapidly. The condition is passed down through families on the X chromosome, which means males are more commonly affected than females.
Risk factors include being male, having Mediterranean, African, Middle Eastern, or Asian ancestry, and having a family history of G6PD deficiency. Newborns with G6PD deficiency may develop severe jaundice. Other triggers besides fava beans include certain medications, infections, and chemicals like mothballs. Some people with mild G6PD deficiency may tolerate small amounts of fava beans without problems. However, most doctors recommend complete avoidance once diagnosed.
How it's diagnosed
Favism is diagnosed through a blood test that measures G6PD enzyme levels. The test shows whether you have enough enzyme to protect your red blood cells. Doctors may order this test if you have symptoms after eating fava beans or if you have a family history of G6PD deficiency. The test is also recommended before taking certain medications that can trigger hemolysis. Many countries screen newborns for G6PD deficiency to prevent severe complications.
During an acute episode, blood tests will show signs of hemolysis including low hemoglobin and elevated bilirubin. Your doctor may also check for damaged red blood cells under a microscope. Talk to a doctor about specialized testing if you suspect G6PD deficiency. While Rite Aid offers general health screening, G6PD testing may require specific lab orders through your healthcare provider.
Treatment options
- Avoid eating fava beans in any form, including fresh, dried, canned, or as flour
- Read food labels carefully as fava beans appear in many Mediterranean and Middle Eastern dishes
- Avoid medications that trigger hemolysis, including certain antibiotics and antimalarial drugs
- Stay away from mothballs and other chemicals that contain naphthalene
- Treat infections promptly as they can trigger hemolysis in people with G6PD deficiency
- Seek emergency care immediately if you develop dark urine, jaundice, or severe fatigue after exposure
- In severe cases, blood transfusions may be needed to replace damaged red blood cells
- Drink plenty of fluids during an acute episode to protect your kidneys
- Carry medical alert identification stating you have G6PD deficiency
- Inform all healthcare providers about your condition before receiving any medication
Frequently asked questions
You must avoid all fava beans, also called broad beans, in any form including fresh, dried, canned, frozen, or as flour. Check labels on hummus, falafel, and other Mediterranean foods as they sometimes contain fava beans. Some people with G6PD deficiency also need to avoid other legumes, but fava beans are the most dangerous trigger. Always ask about ingredients when eating at restaurants.
Favism is one type of reaction that happens in people with G6PD deficiency. Not everyone with G6PD deficiency will have a severe reaction to fava beans, but many will. G6PD deficiency can also cause reactions to certain medications, infections, and chemicals. Favism specifically refers to the hemolytic reaction triggered by eating fava beans.
Favism cannot be cured because it results from a genetic enzyme deficiency. However, the condition is very manageable with careful avoidance of triggers. Most people with favism live normal, healthy lives by avoiding fava beans and other known triggers. The key is knowing you have the condition and taking preventive steps.
Symptoms typically appear within 24 to 48 hours of eating fava beans. Some people experience symptoms within just a few hours of exposure. The severity and timing can vary based on how much you ate and how deficient your G6PD enzyme levels are. Dark urine is often one of the first signs that appears.
Favism can be very dangerous if not recognized and treated quickly. Severe hemolysis can lead to life-threatening anemia and kidney failure. However, with prompt medical care, most people recover fully from acute episodes. The condition becomes much less dangerous once you know you have it and avoid triggers completely.
Favism is most common in males of Mediterranean, Middle Eastern, African, and Asian descent. The condition is inherited on the X chromosome, which is why males are affected more often than females. About 400 million people worldwide have G6PD deficiency, though not all will react severely to fava beans. Family history is a strong indicator of risk.
Children cannot outgrow favism because it is a genetic condition present from birth. However, symptoms may become less severe with age in some cases. Children often have more severe reactions than adults when exposed to fava beans. Lifelong avoidance of triggers remains necessary regardless of age.
Seek medical attention immediately if you have G6PD deficiency and eat fava beans. Watch for dark urine, yellowing skin, extreme tiredness, or difficulty breathing. Go to an emergency room if symptoms develop, as you may need blood transfusions or other urgent treatment. Drink plenty of fluids to help protect your kidneys.
Most vitamins and supplements are safe for people with favism, but always check with your doctor first. Avoid high doses of vitamin C as it can increase oxidative stress in some people with G6PD deficiency. Also avoid supplements containing fava bean extract or other known triggers. Your healthcare provider can review your specific supplement list for safety.
Family members can be tested for G6PD deficiency with a simple blood test. Since the condition is inherited, siblings and children of affected individuals should be screened. Males with an affected mother have a 50 percent chance of having the condition. Females with an affected father will be carriers but may have mild deficiency themselves.