Around the globe rates of IBD are increasing, which includes ulcerative colitis and Crohn’s disease, and it has no clear explanation. However, dietary patterns that affect the gut microbiota (which is particularly sensitive during the first years of life), are thought to be a contributing factor.
Research has looked at dietary patterns and IBD, but this work is largely focused on adults and rarely looks into the possible links to children’s diets. This study was designed to increase knowledge in this area, with the final analysis including dietary information from 81,280 one-year olds enrolled in the All Children in Southeastern Sweden, ABIS, and the Norwegian Mother, Father and Child Cohort Study, MoBa population studies.
Parents of the children were asked to provide specific information about their child’s diet between the ages of 12-18 months old and at 30-36 months old (1 to 1.5 years old and 2.5 to 3 years old). Diet was assessed using the Healthy Eating Index Tool looking at the quality of the whole diet to systematically score and classify their diet as being with low, medium, or high quality.
The intake of individual food groups was also studied, and data on breastfeeding, formula intake and exposure to antibiotics was also included. Higher-quality diets equaled a higher intake of fruits, vegetables, dairy products, and fish, with a lower intake of sweets, snacks, sugary beverages, and limited meats.
The children’s health was monitored from the age of one-year-old for an average of 21 years for those in ABIS and 15 years for those in MoBa, and until the end of 2020/2021 for the others. The analysis revealed that during this time 307 of the children were diagnosed with IBD, 131 were diagnosed with Crohn’s disease, 97 were diagnosed with ulcerative colitis, and 79 were diagnosed with having an unclassified IBD. Additionally, the incidence of IBD was higher in the ABIS study than in the MoBa cohort which could be due to the longer follow-up time in ABIS.
The analysis also revealed that a higher fish intake at the age of one year old was associated with a 4% lower risk of ulcerative colitis compared to a low intake. Higher vegetable intake at one year old was associated with an overall reduced risk of IBD compared to low intake. Not surprisingly, a higher intake of sugary beverages was accompanied by a 42% increase in the risk of IBD as compared to a low intake of sugary beverages.
Looking at the individual food groups, no obvious associations were found between any of the other food groups: fruits, grains, dairy, meat, potatoes, and foods high in sugar or fat, or both. Additionally, at three years of age, only a high intake of fish was associated with a reduced risk of IBD, particularly ulcerative colitis. According to the researchers, the associations remained even after adjusting for formula intake, breastfeeding, antibiotic exposure, and total house income.
Due to the nature of observational studies causality can’t be established, however, the researchers believe their study supports the theory of early life diet affecting the gut microbiome and risk of developing IBD. It was also noted that being conducted in higher-income countries, the results of this study may not be generalizable to lower-income countries with different dietary habits.
“Although we cannot rule out other explanations, the new findings are consistent with the hypothesis that diet early in life, possibly mediated by changes in the gut microbiome, can affect the risk of developing IBD,” says Annie Guo, a dietician and postgraduate student in pediatrics at Sahlgrenska Academy at the University of Gothenburg, and the study’s first author.
