SINGAPORE — A substance found in some milk formulas sold here has been linked to rare cases of allergic reactions.

The Agri-Food and Veterinary Authority of Singapore (AVA) and the Ministry of Health (MOH) on Tuesday (July 12) issued a public advisory on the consumption of products containing Galacto-oligosaccharide (GOS), which is a carbohydrate added in foods and milk formulas as a prebiotic to promote the growth of good bacteria in the gut to help maintain a healthy digestive system.

On average, about two cases of GOS allergies have been reported each year since 2007, MOH and AVA revealed in their joint statement.

There have been no reported cases involving infants below two years old so far, but there have been three cases involving individuals aged between two to five. All the cases have a history of allergic conditions such as eczema, asthma and were sensitised to house dust mites, and all developed allergic reactions on consuming GOS for the first time.

Symptoms of GOS allergy includes hives, itchy eyes, diarrhea, sneezing, runny nose, coughing and chest tightness. The symptoms could take anywhere from several minutes to hours from ingestion of GOS to appear.

The MOH and AVA noted that children or adults who have consumed products with GOS before experiencing any symptom can continue to consume it as it is unlikely an allergy will develop subsequently.

However, AVA and MOH advised consumers with history of allergic reactions to exercise vigilance when consuming products containing GOS for the first time, and those who do experience reactions should seek medical attention, especially if symptoms include giddiness and difficulty in breathing.

GOS has been evaluated to be safe for human consumption and products with GOS have been in Southeast Asia markets since 2007. Worldwide, these products have been consumed by over 100 million infants.

GOS is not commonly associated with food allergy. In the statement, AVA and MOH said: “Our local clinicians are conducting further studies to better understand the mechanism of the GOS in triggering the allergic reactions. We will continue to closely monitor the situation.”

Other cases of allergic reations to GOS have also been reported in Japan and Malaysia.

Below is a list of FAQs issued by Singapore’s Ministry of Health:

Q: Is GOS a permitted food ingredient? Is it only present in food products sold in Singapore? GOS is a permitted food ingredient in many countries including Singapore, Australia, New Zealand, Europe, United States and Asian countries such as China, Japan, Indonesia, Malaysia and Thailand. As a permitted food ingredient, GOS can be added to any foods including infant formula. Currently, GOS has been added to major infant, children and maternal milk brands.

Q: How is GOS different from the other food allergens? Unlike protein which has been established as a common cause of food allergy, GOS is a type of carbohydrate and is not well documented to cause food allergy.

Q: What is atopy? Atopy is a genetic tendency of an individual to become sensitised to allergens commonly occurring in the environment. As a consequence, such individuals can develop typical symptoms of asthma, allergic rhinitis or atopic dermatitis (eczema) in response to the allergens.

Q: Have there been any reports of allergy cases due to the consumption of GOS overseas? Although available in consumer products globally, reports of allergic reactions and anaphylaxis to GOS have been confined to the Asian region — Japan, Singapore, Malaysia and Thailand and likely, Vietnam. The specific geographical restriction of GOS allergy cases to Japan and the South-east Asian region may suggest certain predisposing factors confined to these regions. More research is required to ascertain how GOS causes food allergy reaction. Our local clinicians are conducting further studies to better understand the mechanism of the GOS in triggering the allergic reactions. We will continue to closely monitor the situation.

Q: What is the public health risk? Based on the local study, the estimated prevalence is likely to be up to 3.5 per cent of individuals aged 5 to 60 years with a history of atopy or allergic conditions such as atopic dermatitis (eczema), allergic rhinitis, or asthma. While there have been three cases reported in atopic individuals aged 2 to 5 years, there have been no cases reported in individuals aged less than 2 years.

Q: What is AVA and MOH’s advice to the public? Should we avoid all food products with GOS, to be safe?  Consumers should not be alarmed and avoid products containing GOS unnecessarily. As with any other food allergen, before deciding to exclude any food products from the diet, consumers should consult a specialist experienced in treating food allergies (eg, allergist/immunologist) to identify specific food allergens. The public can find out if a food product contains GOS by reading the statement of ingredients on the product labels, under the term “galacto-oligosaccharides”.

Healthy non-allergic individuals are not likely to develop allergic reactions due to the consumption of GOS. Consumers who had previously consumed, or who are currently consuming GOS products with no allergic reactions, are highly unlikely to have GOS allergy. Consumers with a history of atopy or allergic conditions such as atopic dermatitis (eczema), allergic rhinitis or asthma are advised to exercise vigilance when consuming products containing GOS for the first time.

We advise consumers who encounter an allergic reaction to seek medical attention. If a severe reaction is experienced, they should seek immediate medical treatment at the nearest hospital. As part of follow-up, the patient may be referred to a specialist experienced in treating food allergies for a detailed evaluation to be carried out.

Q: I/My child consumed a milk formulation containing GOS a few times before this. Should I/my child stop taking it? To date, all cases developed allergic reactions on consuming GOS for the first time. If you/your child have consumed it once or twice without experiencing any of the above symptoms, it is highly unlikely that you/ your child have an allergy to GOS, and there is no issue in continuing to consume it. There have been no reports of GOS allergy in children below the age of 2 years.

Q: Is GOS currently listed in food labels? If a food product contains GOS, GOS needs to be declared in the statement of ingredient. The public can find out if a food product contains GOS by reading the statement of ingredients on the product labels, under term “galacto-oligosaccharides”. Currently, the Food Regulations do not specify additional labelling requirements (e.g. warning statement) for food products containing allergens, which is in line with international practices.