One of the emerging themes in nutrition over the last decade has been just how toxic the sugar fructose can be to the body. This sugar, originally touted as ‘healthy’ as a result of the fact that it was found in fruit and did not raise blood sugar levels in the short term, has been linked with a variety of health issues including obesity, metabolic syndrome, ‘fatty’ live and type 2 diabetes. See here for a one and a half hour lecture by American doctor and research Dr Robert Lustig on some of the reasons we really do need to be wary of consuming too much fructose.
Dr Lustig and his team have recently produced another piece of research focusing on fructose, and specifically its potential role in abdominal symptoms of unknown origin. Some individuals, including children, can have symptoms such as bloating and abdominal pain for reasons that are not, in a conventional sense, altogether clear. Sometimes, these individuals end up with a ‘diagnosis’ of irritable bowel syndrome (IBS). IBS is not really a diagnosis at all – it basically is we doctors way of saying “you have abdominal symptoms but we do not know why.”
In my experience in practice, IBS is very often the result of food sensitivity issues (especially wheat) and/or some sort of imbalance in the organisms within the gut (sometimes referred to as ‘gut dysbiosis’). However, according to Dr Lustig’s recent research, presented at American College of Gastroenterology annual scientific meeting in Texas, US, another important cause of abdominal symptoms, at least in children, is fructose.
In this study, which you can read about here, 245 children and adolescents aged 2 – 18 with chronic abdominal pain (perhaps associated with other symptoms such as constipation and/or diarrhoea, wind and bloating) were tested for ‘fructose malabsorption’ (an inability to absorb fructose) with something known as the ‘breath hydrogen test’. In this test, individuals are given fructose, and then levels of hydrogen are measured in the breath. And increase in hydrogen levels in response to ingestion of fructose marks some out as a fructose ‘malabsorber’.
In this study, about 54 per cent of individuals were found to fructose malabsorbers. Those identified as such were then put on a low-fructose diet. The result? About two-thirds of these individuals experienced a resolution of their symptoms.
This study suggests that fructose malabsorption is common in children with unexplained abdominal symptoms, and the fructose reduction can control symptoms in many of these children. One of the reasons that this diet may not have been as successful as it might be is because some children may not have adhered to the low-fructose advice. Also, it’s possible that some of the children have other things going on (e.g. another food sensitivity or gut dysbiosis) that might need remedying for there to be symptom resolution.
To my mind though, this study gives us yet another potential reason to be careful about how much fructose we consume. It’s also going cause me to consider fructose malabsorption in patients who have chronic (long-term), unexplained gut symptoms.