Edible Insects: Can this upcoming sustainable superfood cause an allergy?

Introduction

From fear factor to finer dining, edible insects have been gaining headlines and popularity in recent years. Edible insects are proven to be beneficial to our health, packed with proteins, micro-minerals and unsaturated fats. In the olden days, medieval Rome and ancient Chinese had incorporated insects into their diet.

The other perk of shifting our human palate towards edible insects is for a better greenhouse effect and long-term sustainable food supply chain. Growing insects in farms requires less energy, water and space in comparison to farming poultry. The waste of the insects can be recycled and used as fertiliser to fruits and vegetables.

Amidst making headlines, arousing curiosity in many on this superfood, we also want to explore the safety and association of edible insects with allergic reactions. 

Common edible insects

Currently the Singapore Health Authority has approved 16 species of insects as edible food.

Insects that can be consumed include crickets, super worm, grasshopper, locust, mealworm, moth, silkworm, honey bee, beetle grub and white grub.

What are the health benefits of eating edible insects?

Insects can appear gross and gruesome, but they can be a food source for various good nutrients. Edible insects are rich in proteins, good fatty acids such as omega-3, vitamin B12, riboflavin, iron, zinc, antioxidants, and fiber. Furthermore, the protein chitin that can be found on the skeleton of the insects when consumed has anti-microbial properties. Edible insects also have anti-inflammatory properties, reducing our long term cardiovascular risk factors by regulating our cholesterol and blood sugar.

In a global health perspective, by opting for edible insects, we can ensure better usage of worldwide resources in farming when compared to conventional livestock, resulting in a more durable food supply chain in long run.

Allergy as a Result of Cross-reactivity between Edible Insects, Crustacean Seafood and even Airborne Particles

Those with known shellfish allergy can experience allergic reaction when consuming insects due to the cross-reactive proteins between insects and crustaceans. For example, one with known shrimp or crab allergy may develop allergic reaction when consuming insects.

The common insect allergens are proteins such as tropomyosin, arginine kinase. These proteins play important roles in contracting the muscle and regulating metabolism of the insects. These similar proteins can also be found in shellfish such as crustaceans and mollusks, parasites or even worms. To add things further tropomyosin can also be present in cockroaches and dustmites. Hence, one can have cross-reactivity between shellfish-dustmite-cockroach-edible insect allergies.

How does edible insect allergy occur?

For allergy to occur, one has to be exposed to the allergen for the first time (primary sensitisation), allowing the immune system to recognise and remember the allergen. When the person is exposure again to the allergen for the subsequent time (secondary sensitisation), the body has a recollection and mount an exaggerated immune inflammatory response against the allergen.

In the case of edible insect allergy,

• Primary sensitisation can occur through food- previous shellfish consumption or through airborne- inhalation of dustmite or cockroach allergenic proteins
• Secondary sensitisation occurs when the person subsequently consumes edible insects.

Can cooking, heating up insects help in preventing allergy?

One may ask, if we heat up/ cooked/ boiled the insects, can we prevent allergic reaction when consuming them? Similar to shellfish allergy, due to the stability of the allergenic protein towards heat, processing insects are unlikely to break down the proteins and prevent allergy. You can still develop an allergic reaction consuming cooked insects.

Who is susceptible in developing allergy to edible insects?

Those with known edible insect allergies, past shellfish allergies, known dustmite or cockroach allergies.

What are the symptoms of edible insect allergy?

Edible insect can trigger allergy and present itself with various symptoms. It is important to recognise the symptoms and seek medical attention without delay.

Our body’s various organs can react to insect allergy as below:

Body System	Allergy Symptoms
Face/Mouth Region	Swelling of the face, eyes, lips, tongue, throatWatery eyes
Respiratory	Watery noseCoughBreathing difficultyShortness of breathWheezing
Gastrointestinal	Nausea and vomitingDiarrhoeaAbdominal painBloatedness
Dermatological	Itching of skinHivesEczema

Severe reaction that we should not neglect: Anaphylaxis: an acute sudden severe, dangerous allergic reaction developed over seconds to minutes with systemic symptoms such as dizziness, faint, unable to breath, generalised rash, closing of airway, generalized rash. You will need immediate medical emergency otherwise one can succumb to the allergy.

Another adverse food reaction: histamine poisoning from edible insects

Less common in comparison to allergy, histamine poisoning following eating insects can occur due to a release of histamine from insects following cooking and prolonged storage. Having a large amount of histamine in our body can result in acute symptoms such as generalised rash, difficulty breathing or even anaphylaxis and will require immediate medical attention as this can be life threatening.

How can I know whether I am allergic to insects?

Your healthcare provider can assist you in the diagnosis of insect allergy.

A proper history with clear cut association of allergy symptoms following consumption of insects is important to nail down the allergic diagnosis.

Allergy tests in the form of RAST IgE blood test or skin prick tests against shellfish, dust mites and cockroach particles can facilitate one to understand whether they are likely to be allergic to edible insects due to the cross-reactivity between the allergens. You should not hesitate to reach out to your healthcare provider to discuss on which tests which are suitable in your condition.

How can I manage insect allergy?

• Those who has severe allergic symptoms after consuming edible insects in the past should avoid eating insects.
• Adrenaline pen should be carried along in those with history of anaphylaxis to abort and revert the allergy in life threatening situations.
• Anti-histamines and corticosteroids can be used in alleviating and managing allergy symptoms.
• You should eat insects with caution if you have history of shellfish, dust mites or cockroach allergies.

Take home message…

• One can develop food allergy or histamine toxicity following consumption of insects.
• Allergy towards edible insects can occur in those with shellfish allergy or even airborne allergies such as dustmites and cockroach allergies due to cross-reactivity of the proteins between them.
• Allergic symptoms of edible insects can be varying in severities and can present symptoms affecting various organ. In severe cases, one can develop life-threatening allergy reaction known as anaphylaxis and will require immediate medical attention.
• Allergy tests against shellfish, dustmites and cockroach allergens can be useful in delineating possible allergy towards edible insects.

Curious about whether edible insects might trigger an allergic reaction for you? At Dr Ben Medical Clinic, we can assess your allergy risk and guide you on safe dietary choices. Book a consultation today to get personalised advice based on your health profile. Contact us here.

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