Inflammatory bowel disease (IBD) is a chronic autoimmune condition affecting the digestive system, which includes Crohn’s disease and ulcerative colitis. Although the exact cause of the disease is unknown, genetic predisposition, environmental factors and immune system dysfunction all play a role in its development. A growing body of research suggests that diet may also play a key role in both preventing the disease and alleviating symptoms. Diet alone cannot cure IBD, but a carefully planned diet can help reduce inflammation and improve quality of life.
For many patients, the diagnosis can be frightening, and the vast amount of often contradictory information about diet only serves to increase their uncertainty. What foods should they eat? What should they definitely avoid? Is there even a diet that can prevent flare-ups of symptoms or even the onset of the disease?
In this guide, we set out in detail what the current scientific evidence says about the link between IBD and diet. Our aim is to help you navigate dietary recommendations with clear, understandable and practical advice, thereby reducing any anxiety you may have about this topic. The Endomedix Gastroenterology Centre Our team of experts is committed to ensuring that our patients can make decisions about their health based on the most up-to-date and reliable information.
What is inflammatory bowel disease (IBD)?
Before we delve into dietary recommendations, it is important to clarify exactly what inflammatory bowel disease entails. IBD is an umbrella term that encompasses two main types of disease:
- Ulcerative colitis (ulcerative colitis): This condition affects the large bowel and the rectum. The inflammation is confined to the innermost layer of the bowel wall, the mucosa, and typically starts in the rectum and spreads upwards through the large bowel in a continuous band. Typical symptoms include bloody diarrhoea, a sudden urge to pass stools and abdominal cramps.
- Crohn's disease: This condition can affect any part of the digestive system, from the mouth to the rectum, but most commonly affects the final section of the small intestine (the ileum) and the large intestine. The inflammation can extend through the entire thickness of the intestinal wall, and a characteristic feature is that there may be healthy areas between the affected sections of the intestine. Its symptoms are varied: abdominal pain, diarrhoea (which may be bloody), weight loss, fever and malabsorption.
Both conditions are chronic, which means they require long-term treatment. Their course is typically characterised by fluctuations: symptom-free, inactive (remission) periods are followed by active, inflammatory (relapse) phases. The aim of treatment is to reduce inflammation, achieve and maintain remission, and prevent complications. Diet plays a key supportive role in this process.
The role of diet in the prevention of IBD: What does the science say?
Although no specific diet guarantees the prevention of IBD, research has identified several dietary factors that may reduce or increase the risk of developing the condition. It is important to emphasise that these are correlations, not direct cause-and-effect relationships.
Dietary factors that reduce risk
- High fibre intake: A diet rich in plant-based fibre, containing plenty of vegetables, fruit and whole grains, has been shown to reduce the risk of developing Crohn’s disease. Fibre feeds the beneficial bacteria living in the gut, which produce short-chain fatty acids (SCFAs). These substances, such as butyrate, are essential for maintaining the health of the gut lining and regulating inflammation.
- Omega-3 fatty acids: Az omega-3 zsírsavak természetes gyulladáscsökkentő hatással bírnak. Rendszeres fogyasztásuk – különösen a zsíros tengeri halakból (lazac, makréla, hering) származó omega-3 – hozzájárulhat a Crohn-betegség kockázatának mérsékléséhez.
- Vitamin D: Vitamin D deficiency is common in patients with IBD, and research suggests that low vitamin D levels may increase the risk of Crohn’s disease. Vitamin D plays an important role in regulating the immune system. Its main source is sunlight, but it is also found in oily fish, egg yolks and fortified foods.
- Breastfeeding: Breastfeeding in infancy has been shown to reduce the risk of developing IBD later in life. Breast milk contains components that support the development of healthy gut flora and the immune system.
Dietary factors that increase the risk
- High intake of fat and red meat: A nyugati típusú étrend, amelyet a magas telített zsír, vörös- és feldolgozott húsok fogyasztása jellemez, összefüggésbe hozható az IBD – különösen a Crohn-betegség – megnövekedett kockázatával. Ezek az élelmiszerek elősegíthetik a gyulladáskeltő bélbaktériumok szaporodását.
- Processed foods and food additives: The emulsifiers, thickeners and artificial sweeteners found in highly processed foods can damage the protective layer of the intestinal mucosa and negatively affect the composition of the gut flora, which can exacerbate inflammation.
- A diet high in sugar: Excessive consumption of refined sugar and fructose may also contribute to an increase in inflammatory processes in the gut.
Dietary strategies for patients with IBD
In the management of IBD, dietary therapy has two aims: firstly, to alleviate symptoms during the active phase, and secondly, to prevent nutritional deficiencies and support the maintenance of a disease-free state. There is no single IBD diet that is perfect for everyone. The ideal diet is tailored to the individual, taking into account the type and activity of the disease, any strictures and the patient’s individual tolerance.
Diet during the active, inflammatory phase of the disease
When the condition flares up, the aim is to relieve the strain on the digestive system and alleviate the symptoms (diarrhoea, cramps).
- A low-fibre (low-residue) diet: At such times, it is advisable to avoid foods that are high in fibre and difficult to digest (e.g. raw vegetables, fruit peel, seeds, wholemeal bread). The focus should be on easily digestible foods: boiled potatoes, rice, steamed, peeled vegetables (e.g. carrots, pumpkin), bananas, fruit compotes, lean meats (chicken, turkey) and fish, steamed or boiled.
- A low-fat diet: Fatty foods can make diarrhoea worse, so you should avoid foods fried in large amounts of fat, fatty meats and dairy products.
- Lactose-free: Many people with IBD develop secondary lactose intolerance, particularly those with Crohn’s disease affecting the small intestine. Cutting out dairy products or switching to lactose-free alternatives may help relieve bloating and diarrhoea.
- Fluid and electrolyte replacement: Diarrhoea leads to significant loss of fluids and minerals. It is important to drink plenty of fluids (water, weak tea) and, if necessary, to replenish sodium and potassium (e.g. salty soups, bananas).
Nutrition during the symptom-free (remission) phase
During the recovery period, the aim is to gradually reintroduce a diet that is as varied and nutrient-rich as possible, which supports the health of the gut flora and helps prevent nutrient deficiencies.
- Gradual fibre intake: Foods that are richer in fibre can be reintroduced slowly and carefully. It is worth starting with soluble fibre (e.g. porridge, apples, carrots), as these are gentler on the digestive system.
- A varied, anti-inflammatory diet: A plant-based diet similar to the Mediterranean diet – which includes plenty of vegetables, fruit, whole grains, fish and olive oil, whilst being low in red meat and processed foods – could be an ideal choice.
- Probiotics and prebiotics: Probiotics (beneficial bacteria, e.g. in yoghurt and kefir) and prebiotics (food for beneficial bacteria, e.g. in Jerusalem artichokes, onions and oats) can help restore the balance of the gut flora.
- Replenishing nutrient deficiencies: Az IBD gyakran vezet tápanyaghiányhoz (pl. vas, B12-vitamin, D-vitamin, kalcium, cink, magnézium). A Endomedix Gasztroenterológiai Központ szakorvosai laborvizsgálatokkal ellenőrzik ezek szintjét, és szükség esetén célzott pótlást javasolnak.
Specific diets: FODMAP and SCD
Certain specific diets are also considered in the treatment of IBD, but their use always requires supervision by a specialist and a dietitian.
- Low-FODMAP diet: This diet restricts the intake of fermentable, poorly absorbed carbohydrates (FODMAPs), which can cause bloating, flatulence and abdominal pain. Although it is primarily effective in the management of irritable bowel syndrome (IBS), it may also alleviate functional symptoms in some patients with IBD. The diet should only be followed in the short term, for diagnostic purposes, followed by the systematic reintroduction of foods.
- Specific Carbohydrate Diet (SCD): This is a very strict diet that eliminates most complex carbohydrates (cereals, starchy vegetables, sugars). Although some case studies report success, the scientific evidence is limited, and due to the strict nature of the diet, it is difficult to maintain and may lead to nutrient deficiencies.
What can you do to help prevent it?
Although it is not possible to prevent the onset of IBD with absolute certainty, a health-conscious lifestyle and diet can significantly reduce the risk and contribute to general well-being.
- Eat a high-fibre, plant-based diet: Eat plenty of vegetables, fruit, whole grains and pulses.
- Cut down on your intake of red meat and processed foods: Do not eat red meat more than once or twice a week. Avoid cold cuts, sausages and ready meals.
- Choose healthy fats: Instead of saturated fats, opt for fish rich in omega-3 fatty acids, nuts, seeds and extra virgin olive oil.
- Keep an eye on your vitamin D intake: Spend time in the sun (whilst ensuring you have adequate sun protection) and eat foods rich in vitamin D. If necessary, consult your doctor about taking vitamin D supplements.
- Do not smoke: Smoking is one of the strongest modifiable risk factors for Crohn’s disease. Giving up smoking is essential.
When expert help is needed
The internet is full of dietary advice, but IBD is a complex condition that requires a personalised approach. Self-diagnosis and strict elimination diets not supervised by a healthcare professional can be dangerous and may lead to severe nutrient deficiencies.
If you have digestive problems, or have already been diagnosed with IBD, and would like to find out more about a suitable diet, the Endomedix Gastroenterology Centre csapata készséggel áll rendelkezésére. Tapasztalt gasztroenterológusaink és dietetikusaink segítenek a pontos diagnózis felállításában, a tápláltsági állapot felmérésében és egy olyan, egyénre szabott étrendi terv kidolgozásában, amely biztonságos, hatékony és hosszú távon is tartható. Ne féljen segítséget kérni – a megfelelő szakmai támogatással a gyulladásos bélbetegség mellett is teljes és aktív életet élhet.
