Crohns Disease - Nutrition & Crohn's Disease in Childhood
Nutrition & Crohn's Disease in Childhood
The growth of children with CD slows during episodes of acute intestinal inflammation, which reduce appetite, reduce food absorption (if in the small intestine), and directly limit the growth of bones through the effects of chemicals released into the blood stream. When the inflammation settles and food intake improves, rapid 'catch-up' growth will usually occur to compensate for the period of poor growth. However, if inflammation remains unrecognised or under-treated, or recurs frequently, then nutrition and growth deteriorate. If such problems are protracted and coincide with the growth spurt during puberty, then the height the child eventually reaches as an adult may be less than if the inflammation had not occurred. poor nutrition may also affect the function of almost every body system leading, for example, to impaired recovery from infections and other illnesses.
Fortunately, a chance observation more than 20 years' ago led to the development of a therapy that counteracts the effect of inflammation on nutrition and growth, and which is now widely used in clinical practice. Adults with CD preparing for surgery in the 1970s were given a liquid 'elemental' diet, and their symptoms improved far more than expected.
A recent study done at the University of Chicago confirmed what women have been telling physicians for a long time: during certain phases of their menstrual cycle, women with IBD definitely feel worse. pre-menstrual syndrome (pMS) itself has gastrointestinal symptoms as part of its definition. However, women with IBD experience gastrointestinal discomfort that is above and beyond pMS, and that may sometimes be considered 'mini flare-ups'. In reality, this is a cyclic, predictable phenomenon that is neither random nor 'just in your head'. The cycle of symptoms that women with IBD experience may include diarrhoea, abdominal pain, and constipation. Non-steroidal and anti-inflammatory drugs (eg ibuprofen) often used to relieve menstrual pain, also are known to cause intestinal inflammation.
Subsequent studies demonstrated that if a child with active CD is asked to stop eating a normal diet and to take instead a liquid feed for six to eight weeks, the intestinal inflammation is likely to subside and the child's growth is likely to improve. When compared to treatment with steroids, liquid feeds are slightly less likely to settle the inflammation, but the benefit may last longer and the side effects of steroids avoided. Many doctors who treat adults prefer to use steroids to quieten active CD, but in the treatment of children, feeding has an overwhelming advantage; it maintains growth.
It is not fully understood how liquid feeding settles Crohn's inflammation. Avoiding contact of the diseased gut with solid food may be important; the food may contain proteins that perpetuate inflammation by stimulating the body's immune system. Bacteria in the colon use the residue left over after digestion of food in the small intestine, and may generate by-products which could also stimulate inflammation; during liquid feeding, very little residue passes into the colon. Improved intake of specific nutrients may be important, such as trace elements, long chain unsaturated fats, or the antioxidant vitamins A and E.
It is clear that liquid feeding works in settling inflammation and has few side effects, although these include the requirement for a nasogastric tube in many children who are unable to drink the required volume each day. However, children will often be happy to pass their tube each night for an overnight feed, and take it up again in the morning before they go to school.
Early reports suggest that insertion of a gastrostomy tube (a tube directly through the abdominal wall into the stomach) is safe and helps children with CD cope with the feed. Some children certainly find liquid feeding difficult to tolerate, but many others say that they feel at their best during a course of feeding - they feel as if they have more energy.
We will hear a lot about the importance of good nutrition in CD in the next few years. A provisional study has suggested that even when a relapse has been treated, continuing overnight liquid feeds whilst eating normally during the day may prolong the time in remission before the next relapse occurs.
Nutritional deficiencies can be identified in people with CD even when their disease is quiet, and may affect the ability to fight off infections and to protect their own cells from inflammatory damage.
Osteoporosis (thin bones) is a common feature in CD whose cause is unclear, but which may in part be due to nutritional factors. Steroids will make osteoporosis worse, although it remains to be seen if bones benefit from liquid feeds.
Liquid feeding is now well established as a treatment for active CD. Challenges remain to identify better, more palatable feeds, and to define more accurately the mechanism of action. If future studies show that treating nutritional deficiencies helps people with Crohn's feel better, stay in remission for longer, or need less drug treatment, then adults too may be keen to undertake periods of liquid feeding.
published in the NACC newsletter - Autumn 1999