The Impact of Diet on Ulcerative Colitis
What is Ulcerative Colitis? We are confronted with a chronic autoimmune disease that falls within the category of IBD or Inflammatory Bowel Disease. Although the symptoms of ulcerative colitis can be very similar to those of Crohn’s Disease, the latter can affect the entire gastrointestinal tract, while ulcerative colitis primarily affects the large intestine or colon. Like Crohn’s disease, UC manifests in intermittent episodes or flare-ups.
Ulcerative colitis (UC) is a complex, chronic condition characterized by inflammation of the colon, presenting with a variety of symptoms such as severe bloody diarrhea, abdominal pain, and urgency, often leading to significant lifestyle disruptions. Affecting individuals irrespective of age, the prevalence of UC is notable, with approximately 95% of cases localized to the colon and rectum. As evidenced by current research, dietary interventions play a crucial role in managing UC, particularly through the modulation of gut microbiota.
Causes of Ulcerative Colitis
As mentioned earlier, this is an autoimmune condition, meaning that it is the patient’s own immune system that causes the damage to the intestine. But what triggers this response? The causes leading to this autoimmune alteration are not entirely clear. What has been demonstrated is the existence of a genetic factor in its development; it appears that this genetic predisposition, in combination with environmental causes, is responsible for the onset of Ulcerative Colitis.
Environmental Factors
- Infectious Origin: Any bacterial infection could trigger a reaction from our immune system; hence, the very bacteria present in our gut flora could be one of the potential causes.
- Environmental Pollution: It’s worth noting that the prevalence of ulcerative colitis is higher in urban areas than in rural regions, which leads to its association with atmospheric pollution as one of the possible triggers.
- Diet: The higher prevalence in Western Europe and North America may also be related to dietary habits.
Psychological Factors
Stress and psychological disorders are another common factor in individuals who develop the disease.
Ulcerative colitis affects both women and men equally.
Inflammatory Bowel Diseases affect over 100,000 people each year in Spain, with around 30,000 cases in Catalonia.
Symptoms of Ulcerative Colitis
The symptoms of the disease, much like those of Crohn’s disease, vary according to the area of the intestine affected. A single patient might experience different stages, with the most common symptoms being:
- Abdominal pain
- Constipation
- Diarrhoea (with or without bleeding)
- Fever
- Abdominal distension
- Fatigue
Diet for Ulcerative Colitis
A suitable and personalised diet for each case is particularly relevant, as many individuals suffering from UC may have nutritional deficiencies due to poor nutrient absorption, discomfort, or fear of triggering an acute flare-up. While many individual intolerances exist, certain types of foods tend to cause widespread discomfort in individuals suffering from UC and should be avoided, such as citrus fruits, onions, caffeine (coffee, tea, mate, chocolate), fizzy drinks (carbonated water, sodas…), and obviously, alcohol (beer, wine, cava, vermouth, spirits…). Although there is no definitive cure for this disease, symptoms can be addressed through both medication and dietary measures. The diet for ulcerative colitis must be tailored (as in the case of Crohn’s disease) to the phase in which the patient finds themselves: acute flare or remission period.
Dietary choices are pivotal in either exacerbating or alleviating UC symptoms. Certain food items, particularly red and processed meats, have been correlated with heightened inflammation levels. This association encourages dietary modifications aimed at minimizing inflammation. Recommendations to limit dairy fat are congruent with broader guidelines advocating for a reduction in saturated fat intake—a factor linked to inflammatory responses that can aggravate UC symptoms.
In addition, dietary fats—specifically those originating from coconut oil, palm oil, as well as trans fats often present in processed foods—are shown to promote gut inflammation and distress. Furthermore, additives such as emulsifiers, carrageenan, artificial sweeteners, maltodextrins, and titanium dioxide may contribute to a disruption in gut barrier function and microbiota balance, potentially aggravating UC symptoms.
Diet During an Acute Flare-Up
It is common for many people to associate the intake of specific foods with the onset of an acute flare of the disease. While it is important to acknowledge an individual’s experiences with certain foods, there is often a tendency to eliminate foods simply because their consumption preceded a flare. This may have occurred purely by coincidence and often results in the exclusion of a wide range of foods that may not necessarily be linked to these acute episodes.
During an acute flare, a low-fibre and low-fat diet is recommended.
Prioritise tubers like potatoes and sweet potatoes, including gradually legumes. Vegetables should be cooked and peeled, such as carrots, zucchini, pumpkin, aubergine, or green beans. For protein, light options such as white fish and lean meats are preferred. Regarding fruit, it is advisable to consume ripe fruit without skin, and if possible, cooked; the best-tolerated fruits are apples, or bananas.
Extra virgin olive oil should be the primary fat included, and avocado can also be added to the diet. During flare-ups, nuts, seeds, and pipnuts, as well as butter, mayonnaise, alioli, etc., should be avoided.
Diet During the Remission Phase
Again, a tailored and personalised diet is necessary during stability or remission phases. While a balanced and normal diet should be advised, certain aspects must be taken into account.
Lactose Intolerance
Although there is no scientific evidence linking lactose to the symptoms of ulcerative colitis, many patients often eliminate it from their diets. This may be due to a concurrent lactose intolerance, as symptoms (diarrhoea, bloating…) can be quite similar. Thus, if adverse reactions to lactose occur, testing should be conducted to rule out intolerance.
Gluten and Dairy
There is scientific evidence indicating a certain relationship between ulcerative colitis and coeliac disease, with the incidence of coeliac disease being somewhat higher in individuals with inflammatory bowel disease.
Regarding dairy, there is also evidence that goat or sheep dairy—containing beta-casein A2—is less inflammatory and produces fewer digestive issues than cow’s milk for predisposed individuals.
Therefore, as autoimmune diseases may have better outcomes when following a gluten-free and dairy-free diet, it is recommended to reduce the intake of these products or, in the case of dairy, to at least prioritise goat or sheep dairy over cow’s milk.
Supplementation in Cases of Colitis
- Vitamin D: Maintaining good levels of vitamin D is crucial; therefore, vitamin D supplementation is recommended for individuals with ulcerative colitis, as optimal levels can help control and reduce intestinal inflammation.
- Calcium: Individuals undergoing corticosteroid treatments often experience calcium absorption deficiencies; hence, a physician will assess the need for supplementation with this mineral. Foods rich in calcium include dark leafy greens, tofu, beans, sesame, almonds, sardines, and anchovies.
- Iron: Due to intestinal ulcers and blood loss, iron deficiency or anaemia may occur. Blood tests are important to evaluate iron metabolism parameters to determine whether supplementation is necessary.
- Vitamin B12 and Folic Acid: Due to inflammation, intestinal damage, and reduced food intake during flare-ups, it is common for individuals with ulcerative colitis to experience deficiencies in vitamin B12 and/or folic acid, necessitating supplementation.
Increased Risk of Osteoporosis
The risk of developing osteoporosis is associated with sedentary behaviour, smoking, low body weight, vitamin D deficiency, family history, age, etc. Moreover, individuals with ulcerative colitis who have undergone corticosteroid treatment have seen their bone density compromised, as there is decreased calcium absorption and increased renal excretion.
There are also studies suggesting that the disease itself influences decreased bone density because inflammation leads to increased osteoclasts—cells that break down bone—without a corresponding rise in bone repair.
For this reason, individuals with ulcerative colitis have a heightened risk of developing osteopenia and osteoporosis.
Unlocking the Secrets of Gut Health in Ulcerative Colitis
A newly discovered gut bacterium, Tomasiella immunophila, could be shaking up our understanding of immune defence. This little troublemaker has been found to degrade an essential antibody known as secretory immunoglobulin A (SIgA), leaving our guts more vulnerable to infections and conditions like Crohn’s disease and ulcerative colitis. This study underscores the crucial role of the gut microbiome, particularly the bacterial species T. immunophila, in supporting the mucosal immune and intestinal barrier systems. Its specific nutrient requirements highlight the complex interactions within the gut ecosystem and the challenges in isolating such auxotrophic microorganisms. The research also points to a coevolutionary dynamic between gut bacteria and host species, particularly regarding IgA degradation. By focusing on the functional aspects of these microorganisms, this study provides valuable insights into their symbiotic roles and potential implications for understanding mucosal immunodeficiency and related human diseases.
The Importance of Dietary Patterns in the Modulation of Gut Microbiota
The interplay between diet and gut health is intricate, particularly for those with Inflammatory Bowel Disease (IBD)—a category that includes both Crohn’s disease (CD) and UC. A mounting body of evidence suggests that dietary patterns significantly influence the incidence, progression, and management of these chronic conditions.
Dietary strategies such as the Mediterranean diet, vegetarianism, and low-grain or lactose-specific carbohydrate diets show promise in reducing the risk and severity of IBD. These dietary patterns are associated with lower inflammatory biomarkers typically seen in IBD patients. More importantly, while pharmaceutical interventions remain the cornerstone of UC treatment, many patients experience inadequate responses, underscoring the relevance of dietary interventions as alternative or complementary strategies.
Research indicates that higher consumption of fruits and vegetables correlates strongly with diminished incidence and severity of UC and CD. Conversely, diets high in red and processed meats, ultraprocessed foods, refined sugars, and unhealthy fats have been linked to increased incidence of IBD.
The Role of Gut Microbiota in IBD Management
Recent studies have identified specific bacterial species that correlate with UC and CD, opening avenues for personalized dietary recommendations based on gut microbiota composition and function. For example, researchers have discovered Tomasiella immunophila, a bacterium that compromises gut immune function by degrading secretory immunoglobulin A (SIgA), ultimately increasing the susceptibility to infections and chronic gut disorders such as Crohn’s disease and ulcerative colitis.
This burgeoning understanding of gut microbiota has led to the identification of bacterial species enriching different forms of IBD, with diagnostic models achieving over 90% accuracy based on microbiota composition. Furthermore, innovative diagnostic tools such as droplet digital PCR (ddPCR) outperform traditional tests, enhancing the precision of UC and CD diagnosis by enabling a more straightforward stool test to gauge gut health.
My Thoughts
As a Clinical Dietitian specializing in gut microbiota, I firmly advocate for the integration of dietary approaches in the management of ulcerative colitis. The recent findings underscore the necessity for personalized dietary recommendations that prioritize not just the avoidance of known inflammatory foods but also the incorporation of microbiota-friendly options that foster gut health.
The role of diet patterns in modulating the microbiome cannot be overstated; it is through a finely-tuned dietary strategy that we can potentially mitigate symptoms, enhance the quality of life, and improve the prognosis for individuals suffering from UC and other IBDs. As research advances, we are presented with exciting possibilities for a future where diet becomes a central pillar in the management of inflammatory bowel diseases.
By employing evidence-based dietary strategies and staying abreast of emerging research, healthcare professionals can significantly contribute to the betterment of gut health and the overall well-being of individuals diagnosed with ulcerative colitis.
