There are no available statistics on the number of patients suffering from non-coeliac gluten sensitivity (NCGS) in Malaysia because there’s no such test currently to find out if someone is sensitive to gluten, said consultant gastroenterologist and physician Dr P. Shanthi.
“But it is real and there are papers published by the scientific community,” she said in an interview.
Food containing gluten include wheat, barley and rye.
Dr Shanthi said that currently, the only way of knowing if someone is sensitive to gluten is by putting them on a gluten-free diet and seeing if gastrointestinal symptoms resolve and then re-challenging them with gluten-containing food and looking for symptom recurrence.
She said that coeliac disease (CD), which is proven to be linked to gluten sensitivity, is rare in Malaysia, and it is believed that more people suffer from NCGS.
While there are no statistics on NCGS in Malaysia, Dr Shanthi said the prevalence of irritable bowel syndrome (IBS) varies from 10.9% to 15% (more than three million) of the population. An international journal quoted a global prevalence of 11.2%.
While not all IBS patients are sensitive to gluten, research has shown that certain patients with diarrhoea-predominant IBS may have gluten sensitivity, she said.
“Currently, patients with problematic IBS are prescribed the Fermentable Oligo- Di- Mono-saccharides and Polyols (Fodmaps) free diet because Fodmaps are found to cause bloating, diarrhoea and abdominal cramps in certain individuals,” she said.
Asked why food containing gluten are also listed in Fodmaps, Dr Shanthi said it was because of the starch found in wheat, which forms the biggest component in wheat flour (70-75%).
“The fructants in starch can cause IBS,” she said.
She said that for those with IBS and functional dyspepsia (a chronic disorder of sensation and movement [peristalsis] in the upper digestive tract), fruits with excess fructose and milk could pose an issue.
For instance, apples and pears are categorised as having “high fructose” but not bananas, she said.
Asked if those suffering from inflammatory bowel disease (IBD) – which include Crohn’s disease and ulcerative colitis – need to adhere to a gluten-free diet, she said they do not need to.
“But those with IBD and IBS can try the diet if it helps with their symptoms,” she said, adding that IBD patients still have to take a lot of medicines such as steroids and immosuppresants.
The other group of people who suffer from gluten-related disorders are those with wheat allergy, which could be detected by a blood test for IgE or skin prick test, according to Dr Shanthi.
When exposed to wheat products, they could suffer allergic reactions such as breathing difficulties, swelling or breaking out in rashes, she said.
Paediatric gastroenterologist Dr Nazrul Neezam Nordin said there was insufficient evidence to suggest NCGS exists because the symptoms that NCGS patients say they suffer from such as headache, abdominal bloating and pains and diarrhoea are non-specific, which could be caused by anything and not necessarily gluten.
Patients could be getting bloating from being fructose intolerant or lactose intolerant, for instance, he said.
“So far, none of the evidence has convinced me. There isn’t enough strong evidence to back these claims,” he said, adding that it is also difficult to design a study to assess non-specific symptoms alleged to be caused by gluten sensitivity, contributing to scarcity of evidence.
To make things worse, there is also an absence of a reliable biological marker to confirm or exclude gluten sensitivity, he said.
Dr Nazrul said that the only gluten related disorder that has been clearly defined are CD and wheat allergy.
While he saw only one or two cases of CD as a paediatrician of 11 years in Malaysia, he saw many wheat allergy cases such as lip swelling, rashes and sometimes diarrhoea, which occur quickly after exposure to the allergen, he said.
But CD remains an important and common condition in other parts of the world, he said.
However, he pointed out that for children with recurrent abdominal pain, inflammatory bowel disease (IBD) is an important diagnosis to be excluded as the incidence is increasing at an alarming rate in Malaysia.
Irritable bowel syndrome is another important diagnosis and specific dietary intervention such as low Fodmaps diet and stress control are recommended as part of the management, he said, adding that IBS is a diagnosis of exclusion.
Dr Nazrul said it is not uncommon to see many people suffering from chronic pain such as headaches, body aches, back pains although scans do not show any problems. Hence IBS should not come as a surprise.
Dietitian Celeste Lau said CD patients have to be on gluten-free (GF) diet completely as even tiny amounts could trigger a severe reaction, while those with IBS and IBD do not need to avoid it unless they are sensitive to gluten.
For those without CD but have gluten sensitivity, they should also avoid gluten, she said.
Besides noodles, bread and cakes, food that people may not realise contain gluten are sausages (the wrap may have gluten), burgers (if added with in fillers), licorice, candies, marshmallows, milk pudding, custard (gelatin which may contain gluten), she said.
She also said that some rice and corn cereals may have been added with gluten too while fruit pie fillings and soy sauce too may contain gluten.
“While some experts say those sensitive to gluten can eat oats, others advise otherwise as oats could be exposed to cross-contamination unless certified otherwise,” she said.
Lau said that the GF diet may also help those with severe dermatitis herpetiformis, a skin manifestation of the body’s abnormal response to gluten. It often occurs with CD, but can occur alone without bowel damage.
GF food is not easily available in Malaysia, and those with a gluten issue should read food labels to avoid gluten, she said.
NCGS and coeliac patients also need to avoid food with “may contain gluten” labels because cross-contamination could occur in the manufacturing processes, she said.
She said that many patients had gone to her to see if a GF diet helps, and they include patients with eczema, IBS, IBD, food sensitivities, as well as parents with autistic children, and it worked for some, but not all.
Lau said some IBS and IBD patients could eat food with gluten while others could not, but most could tolerate a small amount.
Since the cause of IBS is unknown, gluten food could be omitted or reduced to see if there is any relief, she said, adding that those suffering from IBS need a low Fodmaps diet and should try and keep their stress levels down.
She said that probiotics may work for IBS patients, but not for IBD patients.
For confirmed IBD patients, they do not need to be on a GF diet unless they have discomfort with gluten, she said.
Lau said IBD patients have malabsorption and digestion problems and they have to go on a low residue diet or low fibre diet as too much fibre may trigger inflammation in their bodies.
“Depending on their tolerance level, they can still eat fruits, but with the skin removed. For vegetables, they can eat the leafy parts and less of the stalks,” she said.
For those with IBD or coeliac, they also suffer from malabsorption and weight gain problems and need a high protein and high-calorie diet such as meat, fish and chicken because they suffer from inflammation, said Lau.
“They also need supplementation with multivitamins. Their vitamins A, B, E may be low and they are prone to anaemia,” she said.