A team from Barcelona, Spain, evaluated the incidence of malabsorption and/or intolerance to dairy products in patients with an acute attack of inflammatory bowel disease (IBD).
They presented their findings on Tuesday at the Digestive Diseases Week 2002, held in San Francisco, California, USA.
Exclusion of dairy products from the diet during acute attacks of IBD is a usual therapeutic measure, although there is no solid scientific basis to justify it.
On the other hand, an increased incidence of metabolic bone disease has been demonstrated in IBD patients, as compared to the general population, which could worsen due to a deficient calcium intake.
A total of 22 patients with acute IBD (12 ulcerative colitis, 10 Crohn's disease) and 18 healthy controls were included in the study.
In these, an H2 breath test was conducted after ingestion of 250 ml of whole milk (approximately 12 g of lactose). This was used to detect lactose malabsorption (H2 excretion > 20 ppm).
Intolerance was assessed by symptom questionnaire.
When either malabsorption or intolerance occurred, the breath test was repeated after ingestion of 250 g of yogurt (equivalent to 250 ml of whole milk, regarding calcium contents).
When an H2 peak > 20 ppm appeared within the first 30 minutes after milk intake, a glucose breath test was performed to rule out intestinal bacterial overgrowth.
In addition, a lactulose breath test was carried out when no H2 excretion was observed to disclose H2 non-producing subjects.
The investigators also administered a questionnaire about dairy product consumption habits.
Subjects on recent antibiotics, enemas, laxatives, or anti-diarrheals were excluded form the trial. Those with upper GI bleeding, past history of chronic obstructive pulmonary disease, or suspicion of intestinal strictures were also excluded.
Lactose malabsorption or intolerance to whole milk was observed in 27% of IBD patients and 50% of controls.
| Most patients with acute IBD are tolerant to and absorb lactose in whole milk.
Nevertheless, neither patients nor controls intolerated or malabsorbed yogurt.
The researchers found that in no case did bacterial overgrowth or H2 deficient production occur.
All patients consumed dairy products before IBD diagnosis.
However, 36% excluded them from their diet after diagnosis, mostly due to medical prescription (73%).
Author Eugeni Domenech said on behalf of fellow colleagues, "Most patients with acute IBD do not exhibit either lactose malabsorption or intolerance to whole milk.
"Those with intolerance/malabsorption to milk absorb and tolerate yogurt well."
"Due to the importance of an adequate dietary calcium intake in these patients, systematic exclusion of dairy products during acute attacks of IBD is not only unnecessary, but can also be harmful," it was concluded.