High-quality early diet linked to lower IBD risk in children

In a recent study published in Gut, researchers investigate the association between early-life diet and the subsequent risk of inflammatory bowel disease (IBD).

Study: Early-diet and risk of inflammatory bowel disease: a pooled study in two Scandinavian birth cohorts. Image Credit: fizkes / Shutterstock.com

Background 

IBD, which comprises both Crohn’s disease (CD) and ulcerative colitis (UC), is an escalating global health issue marked by recurrent gastrointestinal (GI) tract inflammation. The rise in IBD cases might be partly due to dietary shifts; however, the exact cause remains unclear.

Adult studies indicate that high sugar, fat, and red meat intake increases IBD risk, while consuming more fruits, vegetables, and fish reflects better diet quality that can reduce the risk of IBD. Early-life diet, which is crucial for gut microbiome and immune development, has been less studied in relation to IBD risk.

Thus, further research is needed to elucidate the complex mechanisms by which early-life diet influences the development of IBD and inform effective dietary interventions for prevention.

About the study 

The present study used data from two Scandinavian birth cohorts, the All Babies in Southeast Sweden (ABIS) study and The Norwegian Mother, Father, and Child Cohort (MoBa) study.

ABIS, initiated in 1997, invited all 21,700 children born in Southeast Sweden over two years and ultimately achieved a 79% participation rate. MoBa, which started in 1999 and concluded in 2008, is a Norwegian national pregnancy cohort involving 114,500 children, with a 41% participation rate.

The cohorts offered detailed questionnaire data on children’s diets at critical early life stages and were linked to national health registries in Sweden and Norway for comprehensive health tracking. Early-life diet information was gathered from detailed questionnaires and included a wide range of food items such as meat, fish, fruits, vegetables, and sugar-sweetened beverages. Food intake data was analyzed weekly.

Diet quality was evaluated using a modified version of the Healthy Eating Index (HEI), in which the intake of various food groups was categorized into quartiles. The researchers also examined the intake frequencies of food groups like meat, fish, dairy, fruits, and vegetables that were categorized into low, medium, and high intake levels.

IBD was identified using International Classification of Disease (ICD) codes from national patient registers. Cox regression analysis was employed to estimate hazard ratios for IBD, with adjustments for factors such as sex, parental IBD history, and maternal comorbidities. 

Study findings 

The study included 81,280 children, with 11,013 from ABIS and 70,267 from MoBa, who had dietary data recorded at one year of age. During the over 1.3 million person-years of follow-up, 307 children were diagnosed with IBD, 131 with CD, 97 with UC, and 79 with unclassified IBD (IBD-U).

The incidence rate of IBD was 32 for every 100,000 person-years in ABIS and 22 for every 100,000 person-years in MoBa. Most children were weaned from breastfeeding at four to six months of age.

The median follow-up time from one year of age was 21.3 years in ABIS and 15.2 years in MoBa. At age three, 65,692 children remained in the study.

High diet quality at one year of age was associated with a reduced risk of subsequent IBD. This was consistent across ABIS and MoBa, with adjusted hazard ratios (aHRs) suggesting a significant decrease in IBD risk for children with medium or high diet quality as compared to those with low diet quality. However, diet quality at age three was not significantly associated with IBD risk.

Children with high fish intake at one year of age had a reduced risk of IBD, especially UC; however, this association was not observed at age three. In contrast, some intake of sugar-sweetened beverages (SSBs) at age one was associated with an increased risk of IBD; however, this association was not observed at age three.

No significant associations were observed between other food groups, including fruits, grains, meat, dairy, potatoes, sugar-dense and fat-dense foods, and the risk of IBD, CD, or UC.

Subanalyses revealed that diet quality at age one was inversely related to childhood-onset IBD diagnosed before 18 years of age but not diet quality at age three. These results remained consistent, even when excluding children with incomplete dietary data or those diagnosed with IBD before six years of age.

Post hoc analyses, which adjusted for formula intake, household income, and antibiotic use by one year of age, did not affect these observations. Additionally, there was no significant association between IBD risk and diet quality across various examined variables.

Altering the definition of IBD-U to include only the last two years of follow-up also resulted in unchanged estimates. Taken together, these findings emphasize the importance of diet quality in early life, particularly at one year of age, in influencing the risk of developing IBD later in childhood.