Crohn’s disease
Crohn’s disease is a type of inflammatory bowel disease (IBD) that causes inflammation of the gut lining. As a result, parts of the gut become swollen, irritated and ulcerated and the inflammation may (and often does) spread to deeper layers of the bowel.
Symptoms can include diarrhoea, tummy ache, extreme tiredness (fatigue), blood in the stools, malnutrition and weight loss. Crohn’s disease usually affects the gut but can appear anywhere along the digestive system.
Crohn’s disease usually appears in late childhood or early adulthood (before the age of 30) and there are periods of good health, known as remission, alternating with flare-ups. Living with the disease can be troublesome, painful and debilitating. Sometimes, it may lead to serious or life-threatening complications.
There is no known cure for Crohn’s but certain lifestyle changes and therapies can prolong remission, allowing the gut to heal. Many people with Crohn’s disease can live full and active lives.
As a result of the impaired gut lining, people with Crohn’s tend to have reduced absorption of vitamins, minerals and amino acids (proteins) crucial not just for good health but also for the immune system.
What causes it?
Crohn’s disease is an autoimmune disorder, which means that your immune system mistakenly attacks healthy tissue – in this case it’s the lining of the digestive tract.
It is not known exactly what causes the disease but it is thought to be a combination of your genes and immune system dysfunction triggered by an infection (virus or bacteria. When your immune system attempts to fight the invading virus or bacteria, it accidentally attacks the gut lining too.
One of the possible triggers can be an infectious bacterium called Mycobacterium avium subspecies paratuberculosis (MAP). Studies suggest that most people with Crohn’s disease may be infected with MAP.
MAP infection is widespread among cows in the UK. In cows, it causes a chronic inflammatory infection in the intestines called Johne’s disease. MAP can survive pasteurisation and has been found in cow’s milk many times.
MAP is a tough little bug that lives in rivers giving rise to concerns that water supplies may be contaminated. This may explain the clusters of Crohn’s disease seen in areas like Cardiff in Wales where the river that runs through the town flows down from hills grazed by cows.
Avoiding meat and dairy products alone may not be enough to ensure avoiding MAP, but if everyone reduced their intake of animal products there would be fewer cows and less MAP in the environment.
Diet and Crohn’s disease
There is a number of foods that may aggravate symptoms during a flare-up or even trigger one, so it’s best to avoid these:
- Milk and dairy products
- Alcohol
- Caffeinated drinks
- Fizzy drinks
- Artificial sweeteners
- Sugary foods and drinks
- Spicy foods – including hot, chilli sauces and condiments
- Fatty foods
- Highly processed foods
- High-fibre foods (for some but not all)
Your doctor may recommend a low-fibre diet to reduce the risk of gut blockage if you have a narrowed bowel (stricture). This type of diet is meant to reduce the size and number of your stools and so achieve some relief from the troublesome symptoms.
On the other hand, a wholefood vegan diet (high in fibre) has been shown to reduce gut inflammation and increase gut bacteria diversity in Crohn’s patients which helps to improve gut health and reduce flare-ups. If you don’t have strictures, there’s no reason to avoid high-fibre foods in general – you may find that only some exacerbate your symptoms.
Elimination diets can be useful to help you find what foods make your Crohn’s disease worse and what foods are safe. It means eating a very basic diet without any possible trigger foods and then reintroducing them back into your diet, one at a time.
It’s best to work with a specialised dietitian who has experience with Crohn’s disease – there isn’t one exact diet that would suit all Crohn’s sufferers and everyone needs to find what’s best for them.
However, as a general rule, try to have several smaller meals during the day rather than three big meals.
Fibre and Crohn’s disease
Although some high-fibre foods may aggravate Crohn disease, it’s not a rule and there are ways to work around it. If you change the texture of the food, you can make it easier to digest. For example, raw kale and blended kale both contain the same amount of fibre but blended kale is much easier to digest. And it’s similar with other foods – whole nuts may give you trouble but nut butters may be easier to digest.
Other factors
To reduce flare-ups and prolong remission periods, diet is paramount but there are other things you can do to support your gut health, such as drink enough water, avoid caffeine and alcohol, don’t smoke and learn stress-management techniques.
Find out more about diet and inflammatory bowel diseases.
