The stubborn and unpleasant inflammation of the intestinal mucosa with intermittent severe pain in the right abdomen, cramps and diarrhoea, first described in 1932 by New York internist Burill Bernard Crohn and his colleagues, is still regarded as mysterious and not really curable, but only symptomatically treatable. However, there is agreement among doctors that the disease should be classified as an autoimmune disease, as its symptoms respond to immune modulators such as glucocorticoids (cortisone, etc.). It is assumed that an immune reaction against various elements of the intestinal flora is triggered in the mucosal cells. As a result of chronic inflammation, the intestinal wall can eventually become permeable. Fistulas develop, i.e. solid connections between the intestine and other organs (including the sexual organs and the skin), some of which can only be treated surgically. This is also the case for the abscesses which develop and the resulting intestinal obstructions.
For decades there have also been attempts to cope with Crohn’s disease by changing dietary habits. This was obvious, as abdominal pain has always been regarded as an effect of consumption of difficult to digest food. Since the last century it has also been possible to identify individual substances responsible for food intolerance. One of the best-known of these is gluten, the gluten protein contained in wheat flour. It is responsible for the metabolic disease coeliac disease. Some doctors also suspect a similar connection in Crohn’s disease. When nutritionists have studied human nutrition from an evolutionary perspective, cereal products have often been looked at as the culprits. For over hundreds of thousands of years humans lived in small groups of nomadic hunter gatherers who, apart from the wild animal meat they hunted, only ate wild herbs, mushrooms and fruits (mainly berries) – and probably now and then some honey from wild bees.
Until the transition to the cultivation of cereal plants and the inevitable associated sedentarisation about five to ten thousand years ago (known as the Neolithic Revolution), people consumed much more protein and fat than today, but significantly fewer carbohydrates. Only on the basis of a protein- and lipid-rich diet could we develop our large brains, which distinguish humans from all other creatures. The structure of our digestive system also takes this into account. Compared to the intestines of large non-human primates (chimpanzees and gorillas) with much smaller brains, the human small intestine is significantly longer, while the large intestine is shortened. In other words, man has a typical carnivorous gut. His comparatively weak teeth and muscles do not fit. But people can compensate for this disadvantage with their higher intelligence. Since the Neolithic Revolution, however, our carnivorous intestines have suddenly had to cope with a wide variety of cereal products, which were the most important food source in the emerging agricultural societies. Our digestive system has probably not been able to adapt to this over just a few millennia.
So it was obvious to prescribe a diet high in fat and protein, but low in carbohydrates, for those suffering from Crohn’s disease. The Austrian internist Wolfgang Lutz was one of the first to do so. In his bestseller “Life without bread”, which is still available today, he claims to have cured a total of 10,000 Crohn’s disease and colitis ulcerosa patients with his Lutz diet since the 1950s. His diet plan, still propagated today, is considered a precursor of the now more popular Atkins or paleo diet. In contrast to these, it does not completely exclude foods with a high carbohydrate content. However, many doctors and nutritionists today strongly doubt his track record, as it is not based on statistically sound clinical tests or epidemiological studies. A long-term clinical test of the Lutz diet carried out independently by Lutz did not yield any usable results, because many study participants were not able to persevere with the diet. However, for at least some of the bowel patients, the low-carbohydrate diet seems to have really helped.
Whether and to what extent a high-fat diet can really prevent the painful intestinal inflammation can only be clarified by experiments. This is how the internist Prof. Alexander Rodriguez-Palacios started at the medical school of the renowned Case Western Reserve University in Cleveland/Ohio. He fed coconut oil and cocoa butter to laboratory mice suffering from Crohn’s-like symptoms and observed the effects this had on the animals’ intestinal flora and inflammatory markers. Prof. Rodriguez-Palacios recently presented the first results of his experiment at a conference on digestive diseases in Chicago. This shows that a high-fat diet can positively influence the intestinal flora and inhibit inflammation. However, it remains unclear to what extent this finding can be transferred to humans. It seems that people can react very differently to certain food components. What might be helpful for some people, might not necessarily be helpful for others. Therefore, general dietary recommendations should always be followed with caution.
However, there is no reason to condemn saturated fats like coconut oil, as the board of the influential American Heart Association (AHA) recently did. It is no coincidence that AHA receives significant financial support from the associations of manufacturers of polyunsaturated oils (such as rapeseed oil or soybean oil). That should be enough to take their dietary recommendations with a pinch of salt.