Diet and ulcerative colitis Dr Simon Moodie 2009. www.DrSimonMoodie.com In people without ulcerative colitis, certain foods can be a laxative. These include excess alcohol, spicy foods (capsaicin induced diarrhoea), too much fructose (especially in those that malabsorb fructose) such as a very high fruit diet (especially grapes, pears, apricots, fruit juices, dried fruit), artificially sweetened food (sorbitol, mannitol – especially too much sugar free chewing gum). Whether or not you have ulcerative colitis, such foods may induce a looser stool. This is not the same as causing a flare up of your colitis (that is, causing inflammation of your colon – typically persistent looser frequent stools with blood and mucous). Below I discuss what evidence there is that certain foods may be bad for ulcerative colitis. That is, whether any dietary change can reduce colitis flare ups or help treat a flare up. It should be stressed that there have been a huge amount of studies over many years to try and identify a diet change that definitely improves ulcerative colitis and as yet, unfortunately, none has been proven beyond doubt to work. However, as discussed below, some broad recommendations can be made based on what evidence there is. On a separate information sheet I discuss the role of specific food/herbal remedies as treatments including probiotics, probiotics (see “probiotics, herbal remedies and acupuncture for ulcerative colitis” at www.DrSimonMoodie.com). Dietary fats and ulcerative colitis A large multicentre study was recently published (collaboration between UK, Germany, Sweden, Denmark, Italy) (the EPIC study, GUT Dec 2009). This looked at over 200,000 healthy people and followed them up for a few years to see who developed a new diagnosis of ulcerative colitis, there were 126 of these new cases (spread out between all the countries). Careful diet histories were taken and the diet of those who did not develop ulcerative colitis compared to those that did. The results show the following: Food that is bad (clear association with developing ulcerative colitis): high intake of linoleic acid (also called n-6 PUFA). Foods that are high in this are: red meat (particularly pork and beef), cooking oils (especially corn oil and sunflower oils) and polyunsaturated margarines. Alternative foods that have lower amounts of linoleic acid are fish, white meats, olive oil, butter. Food that may be good (may protect against developing ulcerative colitis): high intake of Docosahexaenoic acid (also called n-3 PUFA). Docosahexaenoic acid (DHA) is an omega-3 fatty acid (fish oil) found in cold water fatty fish, including salmon, tuna (bluefin tuna have up to five times more DHA than other types of tuna), mackerel, sardines, shellfish, and herring. To date there are no clinical trials showing that once you have ulcerative colitis changing the type of fat you eat (to low linoleic acid and higher fish oils) will improve your colitis. In support of this idea, though, are several small studies looking at taking fish oil suppliments in ulcerative colitis – these mostly show a slight benefit, although the effect is not strong enough or the trials reliable/large enough for fish oil supplementation to have become a “standard” medical treatment. It makes sense from the above evidence that reducing linoleic acid intake, and increasing fish oil intake might be of benefit and it is a reasonably easy diet change to make. Dietary sulphur and ulcerative colitis There have been some studies suggesting that high dietary sulphur may make ulcerative colitis worse. Magee et al (2005) correlated diet history with activity of the patients’ colitis ( appearance at sigmoidoscopy) and found the following foods to be bad (associated with worse colitis): bitter, white wine, burgers, soft drinks from concentrates, sausages, lager and red wine – these foods have high levels of added sulphite, a preservative. Jowett et al (2004) looked at diet and risk of relapse in ulcerative colitis and found the bad foods (associated with relapse) were meat (particularly red and processed meat), alcohol and protein. The authors point out that these foods are high in sulphur and this may be the linking factor. They also scored foods for sulphur content and found high sulphur was a risk factor (The major sources of sulphur are the sulphur amino acids (found in high protein foods such as red meat, cheese, milk, fish, nuts, and eggs) and inorganic sulphate (in Brassica vegetables and as preservatives in processed foods, particularly commercial breads, beers, sausages, and dried fruit). However, the worst food by far was red and processed meat and it remains only a theory that it is the sulphur in the meat that is bad, it may of course be the linoleic acid as discussed above. No one has yet shown that a lower sulphur diet can improve ulcerative colitis. The consistently bad foods from these studies were red meat especially if processed/preserved including burgers and sausages, as well as too much alcohol (beers, wine). Dietary fibre and dairy products in ulcerative colitis There is no convincing evidence of a role for fibre or dairy products in colitis. That is, there is no evidence that reducing/increasing fibre or reducing dairy products can heal colitis or prevent relapse. However, we do know that high fibre, particularly cereal fibre (e.g.wheat bran) might increase gas and bloating in some people and that these symptoms are a more common in patients with colitis. Likewise, lots of milk can lead to more gas, bloating and sometimes looser stools in some people. Indeed, in irritable bowel syndrome symptoms of bloating and looser stools are common and often people reduce their wheat and milk intake to improve symptoms and sometimes try a formal low fibre diet (see patient information sheets on www.DrSimonMoodie.com on irritable bowel syndrome, low fibre diet and intestinal gas). To be clear, though, there is no evidence that reducing fibre or dairy products can alter the clinical course of your colitis. Summary and recommendations I have been trying to stress two separate areas of dietary treatment here. Firstly, what is the evidence that altering diet can alter the clinical course of colitis (reduce/prevent flare ups and help come off medication)? The answer is that no trial has yet shown convincingly that a dietary change will help but the studies above suggest that the following may be bad: red meat, particularly processed meat; linoleic acid (red meat, sunflower oils, corn oils, polyunsaturated margarines). The following may be good: oily fish. Secondly, certain foods do not worsen the colitis but can lead to uncomfortable symptoms – some foods are slightly laxative, some foods are poorly digested and worsen bloating. It is reasonable to experiment on reducing these if you have these uncomfortable symptoms (particularly if colitis not active).