Omega-3 fatty acids might prevent or reduce symptoms of inflammatory bowel disease (IBD) by decreasing inflammation. A review found that while not all studies agree, research points to the possibility that IBD may, at least partly, be managed by this dietary component.
The review, titled “Inflammatory bowel disease: can omega-3 fatty acids really help?“ was published in the journal Annals of Gastroenterology.
IBD is usually treated by pharmacotherapy, but the review’s authors – Sandra Maria Barbalho and colleagues from the University of Marília in Brazil – argued that alternative approaches should be investigated to improve the quality of life in IBD patients.
Scientists know that apart from a genetically inherited risk, environmental factors — particularly diet — affect the probability of developing IBD. High intake of red meat, saturated fat, refined carbohydrates and food additives, as well as low amounts of dietary fibers, fruits, vegetables, and antioxidants, increase the risk of developing IBD.
Omega-3 polyunsaturated fatty acids (PUFA) are essential nutrients, meaning that humans do not have the capacity to produce them. Foods containing a large amount of omega-3 fatty acids include salmon and sardines, flaxseed oil and certain nuts like walnuts. Unlike saturated fats that cause weight gain, insulin resistance, and tissue inflammation, omega-3 fats improve blood fat levels, reduce weight, and diminish inflammation processes believed to contribute to cardiovascular and other inflammatory diseases.
Much research has been conducted to explore the beneficial anti-inflammatory actions of omega-3. One explanation is that omega-3 fatty acids compete with arachidonic acid – an omega-6 fatty acid and precursor of several pro-inflammatory molecules. The same enzymes break down both arachidonic acid and omega-3 fatty acids but different compounds are being produced in the respective processes. The breakdown of arachidonic acid gives rise to pro-inflammatory molecules while omega-3 fatty acids are broken down to substances having more anti-inflammatory characteristics.
A higher intake of omega-3 could, therefore, shift the balance toward a more anti-inflammatory state.
It has also been suggested that omega-3 can inhibit inflammation by influencing white blood cell migration, adhesion molecule expression and interactions with blood vessel walls. Omega-3 fatty acids are believed to suppress the production of other inflammatory cytokines, as well as decrease the reactivity of immune T-cells. They are also used in the synthesis of compounds essential for resolving inflammation.
Both animal and clinical studies showed that these fats may have a potential role in the treatment of IBD. Patients also tend to see them as both safe and natural.
Animal studies showed that omega-3 fatty acids can improve intestinal morphology and reduce the synthesis of inflammatory molecules. Laboratory experiments also suggest that omega-3 can reduce pain by reducing inflammation and by increasing the production of endogenous opioids – the body’s own painkillers.
A study in IBD patients showed a presence of higher levels of omega-6 fatty acids than omega-3 in the intestinal mucosa, compared to healthy controls. The severity of disease was associated with the amount of omega-6 fatty acids, while a negative correlation could be seen between symptoms and omega-3.
Not all studies are in agreement, and while some show an important role of omega-3 in the course of IBD, others report inconclusive or negative results.
The authors of the review suggest several possible explanations of the varying results. Different forms of omega-3 supplements have different effects when compared to the type found in fish, making it difficult to compare studies. Also, genetic differences in omega-3 fatty acid or other receptors may alter the responsiveness to supplementation.
Differences or problems in study methods such as an insufficient number of patients, the short time period of the study, heterogeneity of IBD, as well as differences between study populations may also impact the results.
Today, there is no consensus on omega-3 dietary recommendations for IBD patients. More research is needed to establish the exact mechanisms by which omega-3 might impact IBD symptoms, and to define the daily amount that could be recommended for IBD patients.