Inflammatory bowel disease: Causes
There is a possibility that genetic predisposition can lead to the development of IBD. Brothers, sisters, children and parents are more prone to develop this. Studies indicate that certain genes increase the susceptibility of the patients getting affected, which are 2p16, ECM1, FCGR2A, 5p15 and regions on chromosomes 12q15, 22q13, IL23R, 1p36 and 7q22. However, these studies are still uncertain. It is also seen that people belonging to certain race and ethnic groups are more likely to get this disease. Statistics indicate that IBD is more prevalent in the US, Europe and South Africa and is more common in men than women.
2. Immune system
There is a theory that an over-reactive immune system can be one of the prime causes for inflammatory bowel disease. It is observed that the immune response system in the patients of this disease gets habitually activated due to the presence of an infection in the body. However, the response trigger of fighting the infection continues, even without the presence of any invading bacteria, fungus or virus. This continuous trigger of the immune system causes inflammation in the intestines. Some experts feel that the faulty immune system fights non-existent infections causing chronic inflammation. Another leading theory suggests that the immune system is not able to categorize the friendly bacteria causing infections, and tends to withhold the infection by causing intestinal inflammation.
3. Air pollution
The toxic emissions from the industries and vehicles are also seen as the causes of inflammatory bowel disease. It is seen that people living in areas having a rich concentration of toxic gases such as nitrogen dioxide, particulate matters and sulphur dioxide, have an increased risk of this disease. Though air pollution does not directly connect to IBD, it does indicate that people face the risk of early onset of suffering from ulcerative colitis and Crohn’s disease. Air pollution gives rise to a number of pulmonary diseases. It is also known to make way for non-pulmonary diseases which includes appendicitis, rheumatoid arthritis and other adverse health effects. Hence, researches partly associate the incidence of ulcerative colitis and Crohn’s disease with exposure to toxic air pollution.
The body’s immune system consists of proteins and cells designed to fight any infection caused due to the presence of the invaders such as bacteria, virus, fungi etc. When there is an infection, the auto immune response causes inflammation of the intestines/digestive tract causing IBD. Studies also show that acute gastrointestinal infections such as salmonella and campylobacter can actually set off this disease. It is also believed that patients who have had previous incidences of infection are also prone to IBD. In this case, though, the infection gets resolved, the strains of bacteria or the virus that caused the infection cause imbalance, which further lead to inflammation of the intestines.
Studies reveal that apart from the other environmental factors that could trigger IBD, smoking is one of the important factors for the same. Smokers are three times more prone to develop this disease. And, smokers are more prone to develop Crohn’s disease than developing ulcerative colitis. Hence, smoking is considered as one of the factors that can be easily controlled to keep IBD away. Smoking can worsen the condition and poses the risk of surgery. Detailed study is still required to ascertain the complete effects of smoking on IBD patients.
6. Psychological factors
Inflammatory bowel disease is not caused by emotional stress. However, the condition could worsen when the patient experiences psychological stress. It is also observed that the patients with ulcerative colitis are more vulnerable to stress which makes the immune system overact. When the body faces stress, the body system triggers hormones to gear up the immune system, which in turn triggers inflammation to fight the stress. Stress must be kept low, especially in the period of remission where the chances of flaring up are more. It must also be noted that stress, along with other factors such as drugs and diet, are conducive in triggering a flare up. Reducing stress helps to relieve ulcerative colitis. Many stress reduction techniques can help to control worsening of this condition.
Studies show that incidences of ulcerative colitis and Crohn’s disease are increasingly seen in urban areas due to increasing industrialization. The hygiene hypotheses indicates that people in these regions, especially early in life, are not exposed to enough germs in order to build a healthy immune system. They are brought up in germless and clean environment making them more susceptible to allergies and infections. The hypothesis recommends that the immune system must be sufficiently stimulated to develop natural immunological response against infections. In the absence of such an environment, it states that people will be more prone to autoimmune diseases as their immune system is incapable of categorizing the friendly bacteria from the infectious ones. Hence, it is important to include friendly viruses, bacteria, gut flora which play a major role in strengthening the immune system.
There is no evidence to show that a specific food is known to cause Crohn’s disease or ulcerative colitis. However, studies show that processed foods that are rich in sugar, salt and refined foods have connection with the symptoms of Crohn’s disease. People who have less intake of essential minerals such as magnesium, potassium, fructose and vitamin C have a link with the symptoms of IBD. It is observed that patients of Crohn’s disease would eat sugary and fatty foods. Dairy products, food high in fiber, fatty foods, gas producing foods (beans, cabbage, lentils etc), raw fruits and vegetables, spicy foods, alcohol and beverages are some that may trigger symptoms of IBD.
Non steroidal anti inflammatory drugs (NSAIDs) may contribute to the inflammation of gastro-intestinal tract. These are drugs that are either sold over the counter or by prescription. It is mainly used to reduce the inflammation. However, studies show that use of anti-inflammatory drugs can cause stomach and intestinal ulcers which can trigger IBD symptoms. It can also worsen the symptoms of ulcerative colitis and Crohn’s disease. It can cause bleeding and inflammation of the intestine and can trigger flare ups for those who are in the period of remission. Aspirin, ibuprofen, ketoprofen, naproxen, ketorolac, indomethacin, etodolac, flurbiprofen, rofecoxib and celecoxib are some NSAIDs that must be avoided by such patients.
Some studies indicate that microorganisms such as Mycobacterium avium subspecies paratuberculosis and strains of E coli bacteria may cause Crohn’s disease. However, there is no concrete evidence for the relationship between the bacteria and the symptoms of the disease. Gastrointestinal infections are caused by bacteria such as salmonella, shigella, Campylobacter jejuni and Helicobacter pylori are also known to cause symptoms of ulcerative colitis and Crohn’s disease.
11. Cold chain hypothesis
The Cold Chain hypothesis states that refrigerated food can be one of the prime causes for Crohn’s disease. It links the usage of refrigeration in developed countries where the incidence of Crohn’s disease is higher than in the developing countries. It indicates that bacteria such as yersinia and listeria survive at low temperatures as one of the potential causes for Crohn’s disease. Hence, refrigerated foods such as beef, pork, hamburgers, cheese are some of the foods that may cause the disease. However, this hypothesis is yet to be proved and confirmed.