The latest food intolerances: Are they causing your bloating?
Uncomfortable bloating after meals may not be just the result of a huge meal. Food intolerances are on the rise, as Dr Sue Shepherd explains.
Do you wake up in the morning with a flat stomach, only to be so bloated by the end of the day that you look like you’re several months pregnant? Well, your symptoms could very well be due to an undiagnosed food intolerance. New research shows that there could be more Australians than previously thought who suffer from intolerances to common foods such as fruit, vegetables, artificial sweeteners and dairy foods – resulting in bloating, cramping and other symptoms of Irritable Bowel Syndrome.
What’s causing it?
Many of the common foods we eat contain a variety of small, naturally occurring carbohydrate molecules. These molecules don’t cause any problems for most people, but some of us don’t digest them well – leading to symptoms like bloating. Collectively, these molecules are known as FODMAPs, which is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (now you know why the abbreviation ‘FODMAPs’ is used!).
Common examples of FODMAPs include:
Fructose: a single sugar that naturally occurs in fruits, honey and some vegetables. It’s thought that 30–40 per cent of IBS sufferers, and also 30–40 per cent of the general population, suffer from fructose malabsorption (although symptoms can vary widely in how much discomfort they cause).
Fructans: a chain molecule of many fructose sugar units joined together, naturally occurring in wheat, onions and many other foods. Because fructans are combined fructose molecules, people who suffer from fructose malabsorption should avoid these also.
Polyols: often used as an artificial sweetener in gums and confectionery (usually with the warning ‘excess consumption may have a laxative effect’), and naturally occuring in some fruit and vegetables.
Lactose: a double-sugar that is contained in the milk from cow, sheep and goat.
Galactans: a chain molecule of many single sugar units joined together, commonly found in legumes, baked beans, kidney beans, chickpeas and lentils.
Why do these foods cause bloating?
When FODMAP molecules are unabsorbed in our small intestine, they continue through the digestive tract, where bacteria ferment them. This releases gases, which can cause bloating, cramping and other symptoms. Those with Irritable Bowel Syndrome (IBS) also commonly experience these symptoms.
How are FODMAPs and IBS related?
IBS is a condition where the nerve endings in the digestive system are hypersensitive to stimulus, such as excess gas production. FODMAPs can cause excess gas production, and are a common food trigger for IBS, leading to symptoms such as bloating, excess wind, abdominal pain and changes in bowel habits such as diarrhoea, constipation or a combination of both. It’s thought that IBS affects around 15 per cent of Australians and two to three times more women than men.
IBS isn’t always caused by FODMAPs – you may suffer from IBS because of other factors, such as stress. However food is often a cause for symptoms, and a low-FODMAP diet has been found to relieve symptoms of IBS in 75 per cent of patients.
How do I know if FODMAPs are a problem for me?
Not everyone has a problem with every FODMAP. For example, you might be lactose intolerant, but have no problem with fructose. If you’re suffering from bloating or other uncomfortable symptoms, a hydrogen breath test might help – this can identify both fructose and lactose malabsorption. However, breath test results can sometimes be difficult to interpret, so you may still benefit from a low FODMAP diet, even if results come back negative.
Beating the bloat
Research has found a low FODMAP diet to be a very effective way to be ‘bloat-free’, but there’s no need to restrict all FODMAP foods – just those that give you symptoms. In other words, if you’re diagnosed with a fructose intolerance, there’s no need to avoid lactose.
Many people with FODMAP intolerances also find that symptoms are ‘dose dependent’, so you don’t need to be as strict as in avoiding foods as someone with a severe allergy. Rye and garlic, for example, contain fructans but many people find that they don’t cause severe symptoms when consumed in small amounts. Similarly, people with fructose intolerance don’t necessarily need to cut out all fructose from their diet – they simply need to avoid foods that contain excess fructose (more fructose than glucose in the food).
If you’re considering following a low-FODMAP plan, it’s worth speaking to an Accredited Practising Dietitian who specialises in low-FODMAP diets – they will be able to help you create a nutritionally adequate, bloat-free eating plan that’s right for you.