China: People who frequently take fish oil supplements may be at lower risk for inflammatory bowel diseases (IBDs) and its subtype ulcerative colitis (UC), states a recent study published in Frontiers in Nutrition. Also, users of fish oil were shown to have lower levels of baseline C-reactive protein levels ad higher baseline albumin levels versus non-users.
With advancements in global industrialization and diet pattern transformation, there has been an emergence of inflammatory bowel diseases. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), enriched in fish oils, are known to have health benefits. There is a scarcity of evidence of the association of fish oil supplements with the risk of IBD development.

Against the above background, Xiaoxu Huang, Department of Clinical Nutrition, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China, and colleagues aimed to investigate the association between the use of fish oil supplements and the risk of developing inflammatory bowel diseases among the general population in a prospective cohort study.
The study included 447,890 participants aged 40–69 years from the UK Biobank. To obtain data about fish oil intake at baseline, a touch screen questionnaire was used. International Classification of Diseases (ICD-9 and ICD-10) or self-report ascertained the incident diagnoses of IBDs.
During an average of 8 years of follow-up, the researchers documented 1,646 incident cases of IBDs, including 533 incident cases of Crohn's disease (CD) and 1,185 incident cases of ulcerative colitis (UC).
Key findings include:
After multivariate adjustment, the use of fish oil was associated with a 12% lower risk of IBDs (HR: 0.88) compared with non-consumers.
For subtypes of IBDs, fish oil supplementation was inversely associated with a 15% lower risk of UC (HR: 0.85) but was not correlated with the risk of CD.
Fish oil supplementation showed a significant inverse correlation with baseline CRP levels (β = –0.021) and a positive association with baseline albumin levels (β = 0.135) after adjustment for multiple varieties.
"The habitual use of fish oil supplements significantly lowers the incidence of IBDs and its subtype UC but not CD, the authors wrote. This may be partly due to the anti-inflammatory effect of marine n-3 PUFAs.
"More trials with large sample size and a long duration of follow-up are warranted to develop the recommendations about intake of n-3 PUFA supplements for the prevention of incident IBDs in the future," they concluded.
Reference:
Huang X, Li Y, Zhuang P, Liu X, Zhang Y, Zhang P and Jiao J (2022) Habitual Fish Oil Supplementation and Risk of Incident Inflammatory Bowel Diseases: A Prospective Population-Based Study. Front. Nutr. 9:905162. doi: 10.3389/fnut.2022.905162