A proper diet can help prevent malnutrition and avoid nutrient deficiencies. Eating well will improve energy levels, help with symptom management, enhance immunity and the body’s ability to heal, and improve overall quality of life. It is important to focus on meeting energy and nutrient needs as individuals with Crohn’s disease are at risk of becoming malnourished.
Malnutrition in Crohn’s Disease
Malnutrition occurs when the body is lacking nutrients – from suboptimal intake through diet, from malabsorption or loss of nutrients in the gastrointestinal tract. When malnutrition occurs, common side effects are rapid or unintentional weight loss, and worsened fatigue. There are a few reasons individuals with Crohn’s disease are at a higher risk for malnutrition. For one, it is common to experience a loss of appetite with the disease whether it comes from a general sense of feeling unwell during a flare, or a fear that eating anything will worsen symptoms. This decrease in appetite often leads to a decrease in food intake. Another common issue with Crohn’s disease is that individuals may have a variety of food intolerances that greatly restrict usual intake. Other factors that may put patients with the disease at risk for malnutrition include increased nutrient and caloric requirements from the state of chronic disease itself, side effects of medications, and malabsorption of nutrients - especially when inflammation is present.
Effects of Crohn’s Disease on Digestion
It is important to first understand the general process of digestion before realizing the effects of Crohn’s disease on nutrient digestion and absorption. Digestion can be defined as the process of food being converted into substances that can be absorbed by the body. The body absorbs nutrients from food in order to function properly. Most absorption of nutrients occurs in the duodenum and jejunum, the first two portions of the small intestine, with the exception of vitamin B12 which is absorbed in the ileum. Watery food residue and undigested secretions pass into the large intestine, or colon, where water is recycled. Solid, undigested food mixes with bacteria living in the large intestine to form bowel movements. In Crohn’s disease, the inflamed small intestine is less able to properly digest and absorb nutrients, and these partially digested foods then travel to the colon where they may cause diarrhea. Nutrient deficiencies may occur from inability for nutrients to be absorbed into an inflamed small intestine, or from increased losses with bowel movements.
Nutrients at Risk with Crohn’s Disease
There are many nutrients at risk of deficiency with Crohn’s especially when there’s a decrease in food intake. However, certain nutrients are at a higher risk of deficiency. Which nutrients at risk also depend on the area of the small intestine that is affected. The two macronutrients at largest risk of deficiency are protein and fat. Bowel protein loss is correlated to the extent of intestinal inflammation – when more inflammation is present there are more protein losses from the bowel, and extra attention should be placed getting enough protein in the diet. Fat malabsorption occurs in some individuals with Crohn’s disease. At particular risk are those who have had a long terminal ileal resection (greater than 1 meter). If fat malabsorption is an issue, the fat-soluble vitamins A, D, E, and K are also at risk of deficiency. Vitamin B12 may be at risk if the disease affects the ileum or for those who have had a portion of the ileum resected, as vitamin B12 is absorbed in the terminal ileum. For these individuals, a physician will likely prescribe vitamin B12 injections. Additionally, folate may be at risk when being treated with methotrexate and sulphasalazine as they specifically increase folate requirements. Calcium and vitamin D are also at risk when using steroids over a prolonged period of time, and possibly from decreased intake if lactose intolerance is an issue. Minerals at risk include iron, zinc and magnesium – primarily due to inflammation in the intestines and losses from chronic diarrhea.
Below is a chart summarizing nutrients at a higher risk of deficiency with Crohn’s disease, and dietary sources of these nutrients:
For more information on how to avoid malnutrition and meet energy and nutrient needs, we also have an article on “Practical Strategies for Optimal Nutrition with Crohn’s Disease”. You may also consider contacting a registered dietitian who specializes in digestive health disorders for more information.