G6PD deficiency symptoms & what to avoid

Many of you may at some point in your life have heard the term “favism”. But did you know that it refers to the lack of G6PD enzyme? What exactly is this disorder and what should you watch out for if you have it?

What is G6PD deficiency?

It is an inherited condition characterized by deficiency of the enzyme glucose 6-phosphate dehydrogenase (G6PD).

In fact, it is the most common inherited enzyme disorder. It is not contagious, it is often asymptomatic, while sometimes it can lead to hemolytic anemia, both in adults and children.

It is usually diagnosed during childhood and it is more common in males. Globally, it appears to affect about 5% of the population.

The G6PD enzyme contributes to the production of the powerful antioxidant glutathione, and appears to support immune system function. Furthermore, it protects red blood cells from oxidative stress and related damage.

Diagnosis and normal levels

In Greece since 1979 all infants after their 4th day are tested for G6PD deficiency with the semi-quantitative Beutler method. However, it is suggested that babies also get tested for the enzyme (quantitatively) after the 6th month of life.

The frequency of the disease in our country is quite high, as a result of which it has been included in the list of diseases checked during Neonatal Screening.

At any time, of course, each of us can measure their G6PD values to identify a possible deficiency or in case you search for what caused you hemolytic anemia.

G6PD deficiency is diagnosed through blood tests at a diagnostic center. Normal values for the enzyme vary depending on the type of test being performed and are also affected by other factors. For this reason, you should always discuss the results with your physician.

Normal G6PD values in Greece usually range between 7-20 U/gr Hb (units per gram of hemoglobin).

Depending on the laboratory where the analysis is performed, the value range can vary from 7-16.3 U/gr Hb for children and adults, as well as from 6.75-11.95 U/gr Hb.

G6PD deficiency symptoms

People with G6PD deficiency are very likely to never know they have it as they often remain asymptomatic! Especially in cases where someone is not exposed to certain substances and other risk factors for the disease, they may not show any symptoms.

The way that many discover that they have a G6PD deficiency is through a hemolytic episode, usually after contact with substances, foods (fava beans) or drugs that can trigger it, or after an infection.

The most characteristic symptoms that this deficiency can lead to include the following:

• Jaundice (yellowing of the skin and eyes)
• Dark red/orange urine
• Hemolytic anemia (rapid breakdown of red blood cells)
• Pallor (in case of anemia)
• Fatigue / tiredness
• Shortness of breath
• Irregular heartbeat / palpitations
• Headache
• Stomach ache
• Weakened immune system (increased risk of infections)

In any case, G6PD deficiency is a manageable condition and does not seem to affect life expectancy, nor the quality of life. However, it is recommended to avoid the so-called triggering factors, which we will analyze below.

What to avoid

So what should you avoid if you’re G6PD deficient?

The most common triggers include the following:

• fava beans
• certain medicines such as some antibiotics, anti-inflammatories and anti-malarials
• some herbs (eg Chinese herbs, ginkgo biloba)
• certain vitamins in a specific form (eg vitamin C as ascorbic acid).

Below we have detailed lists of foods and substances that need attention. However, it is important to emphasize that not all of these are prohibited for everyone who is deficient in the enzyme, as many of them do not cause any symptoms in most people.

1. Foods you should avoid

The food most associated with G6PD enzyme deficiency is fava (fava beans), sometimes leading to hemolytic anemia. Many people, however, do not experience symptoms after eating them.

Although each case is different, foods and drinks that seem to warrant special attention include the following:

• Fava beans
• Bitter Melon or Goya (Momordica Charantia)
• Liqueur
• Tonic water
• Campari
• Legumes such as chickpeas, black-eyed beans and lentils
• Peas
• Falafel
• Drinks with quinine
• Peanuts
• Soy products with components (excipients) of legumes
• Foods with menthol

2. Chemical substances and medication

The list of drugs and substances that should be avoided by people with G6PD deficiency is a pretty big one and includes, among others, the following:

• Naphthalene
• Naphthoquinone (Henna) produced from the herb Lawsonia inermis
• Certain medications/substances (eg malaria treatment, some analgesics/antipyretics, antibacterials, NSAIDs, sulfonamides/sulfones) – You should ask your doctor for a detailed list so as not to rule out entire substance groups you may not need to!
• Quinine
• Methylene Blue
• Menthol
• Camphor
• Artificial colorants (mainly blue ones)
• Flower Pollen
• Fenugreek

3.Nutritional supplements

When it comes to food supplements, there are some that have been shown to sometimes cause problems to people with G6PD deficiency, but not to everyone who has it. The main ones are the following:

• Vitamin C as ascorbic acid
• Vitamin K
• Supplements with ginkgo biloba
• Supplements with Chinese herbs
• Μint/menthol supplements
• Herbal Formulas (few facts are known about the safety of taking them)

What could help?

As already mentioned, what mainly helps people with G6PD deficiency is to avoid the stimuli that can cause symptoms/complications.

However, it is important that we also point out some ground lifestyle tips, which are briefly mentioned below:

• Avoid alcohol consumption
• Avoid smoking
• Exercise daily – Moderate-intensity physical activity on a daily basis is recommended, but you should avoid very high-intensity exercise or overtraining!
• Sleep and rest well
• Manage your stress and anxiety
• Follow a balanced diet, rich in antioxidants!

Regarding nutritional supplements, it seems that taking vitamin E is likely to help, thanks to its antioxidant effect. In addition, if you have developed anemia, nutritional supplements for this condition may also benefit you.

The aforementioned tips will help you strengthen your immune system and protect your body from oxidative stress.

It is vital that you contact your doctor about what you should avoid, while it is recommended to always carefully read labels or instruction leaflets on medicines, nutritional supplements and foods.

Note: People may also get “acquired” G6PD deficiency, a potentially curable condition if the underlying cause (diabetes, hyperaldosteronism, and other endocrine disorders) is treated.