Fasting reduces Crohn’s disease symptoms by 40%: Study

Restricting eating to an eight-hour window can drastically reduce the symptoms of inflammatory bowel disease (IBD), a new Canadian pilot study has shown.
 
However, one RACGP expert believes the study’s ‘limitations’ prevent its findings from being applied to ‘real life’.
 
Published in the Gastroenterology journal, the study shows that time-restricted feeding (TRF), a form of intermittent fasting, reduced symptoms of Crohn’s disease by 40% and abdominal discomfort by 50% in 12 weeks in people with obesity or overweight.
 
Crohn’s disease and ulcerative colitis, collectively known as IBD, affect about 180,000 people in Australia and around one in 10 people worldwide.
 
TRF involves eating all meals within a set eight-hour window each day, and fasting for the remaining 16 hours, without cutting kilojoule intake.
 
The randomised controlled study from the University of Calgary tracked 35 adults with Crohn’s disease and overweight or obesity over 12 weeks, with 20 participants assigned to TRF and 15 to their usual diets.
 
Despite all participants eating similar foods in similar amounts, TRF participants showed ‘a significant decrease’ in visceral fat and key inflammatory signals in the blood, said the researchers, including lower levels of leptin and PAI-1.
 
The TRF cohort also each lost about 2.5 kilograms in weight, while those in the control group gained about 1.7 kilograms.
 
While the researchers acknowledge longer-term studies are needed, they said ‘nonetheless, the magnitude of change observed within 12 weeks highlights TRF is a feasible adjunctive nutritional strategy in Crohn’s disease with overweight and obesity’.
 
However, Chair of RACGP Specific Interests Obesity Management, GP and dietitian Dr Terri-Lynne South told newsGP that, given the study’s ‘really small’ number of participants and short time frame, it is difficult to give the findings much weight.
 
‘It’s really important that these studies are done, to give people different management options, but we need to apply it to real life,’ she said.
 
‘If we consider that Crohn’s disease is a chronic disease, we need to make sure that people can continue with the intervention lifelong.
 
‘The disease state is not going to go away, so the intervention needs to be something that’s long term as well.’
 
Dr South said she frequently sees patients who can make ‘significant lifestyle changes’ for a short period of time, but the challenge lay in sustaining such changes.
 
‘I make a joke with my patients that there’s a reason it’s a 12-week challenge and not a 12-month challenge, when you see these “improve your health” type of things,’ she said.
 
‘From a human motivation point of view, it’s about changes to eating habits in the long term that is part of the proof. And I don’t see that [in the study].
 
‘I would prefer to assess the impact on that at a minimum of one year, or preferably two years.’
 
Dr South also does not believe that the control used in the study, a usual diet eaten at usual times, is adequate.
 
‘What I’d really like to see is, is this actually more about a natural calorie restriction because of those time restricted eating rules, as opposed to that there was something special about having a longer gut rest, for example,’ she said.
 
‘In general, time-restricted eating is one option from an obesity management point of view, because we’re looking at a high level of overweight or obesity in Crohn’s cohort, and that obesity is correlated to information.
 
‘So, from a “does this make sense?” point of view, yes, it does. But I just feel that there’s a lot of limitations to this study before we could apply it more generally.’
 
Crohn’s and Colitis Australia says the growth of IBD in Australia is the highest in the western world, with local cases expected to reach 200,000 within 10 years.
 
‘A lot of chronic diseases are increasing, so I’m not surprised,’ said Dr South.
 
‘I guess the question is, why? There is presumably some sort of environmental factor that’s come in to play there, and I do think that it’s likely to be from a gut health point of view.’
 
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