Gut instinct

Sunday, November 18, 2012

IF you suffer from irritable bowel syndrome (IBS), you’re not alone.

Recent research estimates that roughly 15% of the population are affected by this condition, with a particularly high prevalence among younger adults. Women are about twice as likely as men to suffer from IBS, with a preponderance of sufferers also reporting habitually heightened levels of psychological stress.

What is it?

IBS is characterised by gastrointestinal signs and symptoms such as nausea, abdominal bloating, diarrhoea and flatulence. Often these occur intermittently, with acute episodes punctuated by periods of remission.

Whatever its origins, IBS has always been a condition which doctors and other clinicians found difficult to diagnose and treat.

In the ’70s and ’80s an “exclusion diagnosis” was usually made when all the potential “organic” causes had been ruled out. Hence, if blood tests, scans and scopes didn’t reveal an identifiable gut disorder, the patient was usually deemed to have IBS.

In 1992, explicit “Rome II” criteria for the diagnosis of IBS were formulated. While these guidelines made it easier to determine if a person was suffering from IBS, they didn’t articulate the mechanisms of the disease, making it difficult to formulate effective treatment interventions. Consequently, patients were generally advised to increase their fibre and fluid intake, to take moderate exercise and to re-populate the bowel with “friendly bacteria” using probiotic yoghurts to counteract recent illness or antibiotic use.

Additionally, they were almost always advised to manage their stress levels, given its presumptive role as an exacerbating factor in IBS. Despite the ineffectiveness of these guidelines for many sufferers of IBS, treatment evolved very slowly.

Game changer

In 1997, Sue Shepherd, a young Australian dietician, formulated an experimental IBS diet which focussed on the exclusion of poorly digestible carbohydrates. These would later become known as FODMAPs, the acronym standing for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols.

Shepherd’s rationale for the diet was that instead of being digested and absorbed high up in the human gut, these carbohydrates (especially fructose, fructans and polyols) were arriving undigested into the large intestine. Here, the normal bacteria living there fermented these FODMAPs producing lots of gas (hence the bloating and flatulence), and creating smaller carbohydrate fragments which sucked additional fluid into the large intestine (which explains the diarrhoea).

The low FODMAP diet avoids high fructan foods (leeks, rye); high galactan foods ( beans, lentils, cabbage) and high polyol foods (peaches, cherries). It also limits high fructose sources (fizzy drinks, apples, honey) and high lactose products (milk) in individuals with demonstrated malabsorption of these specific carbohydrates. Clinical trials have indicated that this low FODMAP diet, when properly formulated by a trained dietician, is effective in reducing abdominal signs and symptoms in more than 70% of IBS patients, a dramatic improvement on standard treatment.

Other interventions

The low FODMAP diet isn’t the full story. Indeed, the researchers involved in its development acknowledge the value of other lifestyle changes such as the regulation of eating times, the avoidance of other problematic foods and the implementation of stress management strategies in the treatment of IBS.

The latter has come into sharper focus recently, with the discovery of extensive neurological pathways linking the brain and the gut. This has led some experts to refer to the gut as a “second brain”, a sensory organ that responds significantly to psychological stimuli, and whose activity may be profoundly affected by our innate personality type and the stressors we encounter in life.

With the global food intolerance market now worth over $8bn, there will doubtless be strenuous efforts to discover much more about this enigmatic condition in years to come. But for the moment, sufferers can be assured that symptomatic relief of IBS is now a realistic and very achievable goal.

¦ Dr Daniel McCartney, lecturer in Human Nutrition & Dietetics at DIT

HEALTHY SNACKS

Food to go

Kiwi fruit are extremely rich in vitamin C, as well as being high in fibre and low in fat and calories.

They also provide generous amounts of potassium — good for blood pressure control and bones — and folate — good for heart health and for normal foetal growth in pregnancy.

A QUICK FIX

Winter warmer

Quick fry one clove of crushed garlic, a whole chopped onion and 500g of vegetarian mince. Add some shredded carrot, a tablespoon of Worcester sauce and 200mls of chicken stock, and reduce by cooking until thick. Meanwhile, boil and mash one large sweet potato (cubed). Put the mince in a baking tray, top with the sweet potato and bake in the oven for 20-30 minutes.

IN THE FRIDGE

Frozen salmon fillets

These can be seasoned with black pepper and crushed garlic and cooked in the microwave in three minutes. They’re high in omega-3 oils which are very good for the heart and brain, as well as having potent anti-inflammatory properties. They’re also rich in vitamin D and vitamin A, two critically important nutrients which are often lacking in Irish diets.

Home