Dr Harald Stossier is the king of food intolerances. Head of the famous Viva Mayr clinic in Austria, and now also practising in London, he can spot a gluten intolerance or an adverse reaction to dairy products a mile off. So when he attributes my tiredness, depression and bloating to one kind of food I’m expecting the usual suspects.
''Fruit,’’ he says, smiling. ''Or rather, should I say, fructose.’’
Fruit? How on earth can anyone be intolerant of fruit? We are told to eat more fruit because it is so incredibly good for us. But for the estimated 30-35 per cent of the population who suffer from fructose malabsorption (FM), eating something as seemingly innocuous as an apple could cause bloating and stomach pains, fatigue and confusion, depression and anxiety and even sore, aching eyes.
Fructose is a sugar that occurs in varying degrees in fruit, while fructan (chains of fructose molecules) occurs in some vegetables and also in wheat. Usually these are processed in the small intestine but for people with FM, they pass largely unchanged into the large intestine where they wreak havoc.
''The sugars stay in the bowel and produce hydrogen or methane gas, hence the pain and gassiness,’’ explains nutritional therapist and lecturer Emma Wells. She believes a large proportion of her clients with irritable bowel syndrome or chronic fatigue have problems with fructose.
But how can it affect mood? Dr Stossier says that FM affects levels of the amino acid tryptophan, a precursor of serotonin, one of the major hormones that regulate mood and sleep. Many people, he says, are taking antidepressants unnecessarily when they just need to change their diet.
The good news is that the right diet can apparently switch off FM — and you don’t need to avoid all fruits all the time. Australian research (reported in the Journal of the American Dietetic Association) found that steering clear of foods high in fructose helped the majority of sufferers.
Source - Telegraph