High-quality, early-life diet protective against IBD?

High diet quality and fish and vegetable intake in early life were associated with a reduced risk of inflammatory bowel disease (IBD), a pooled analysis suggests.

“In this pooled study of two Scandinavian birth cohorts [ABIS* and MoBa**], children with high diet quality [and high fish and vegetable intake] at 1 year of age had a reduced IBD risk compared with children with low diet quality,” said the researchers.

Fish, veggies are key

After adjusting for the child’s sex, parental IBD, origin, educational level, and maternal comorbidities (model 1), adjusted hazard ratios [aHRs] for IBD risk with high vs low diet quality at age 1 were 0.61 and 0.79 in ABIS and MoBa, respectively. [Gut 2024;73:590-600]

On pooled analyses, 1-year-old children with medium or high vs low diet quality had a reduced risk of later IBD (pooled HRs, 0.74 [ABIS] and 0.73 [MoBa]). The estimates remained unchanged in model 1 (pooled aHRs, 0.75 for both medium and high diet quality).

Meta-analysis of estimates across cohorts revealed that children with high vs low fish intake at age 1 had a reduced risk of later IBD (pooled HR, 0.66), a trend that was sustained in model 1 (pooled aHR, 0.70).

Pooled analyses of high vs low fish intake at age 1 yielded aHRs of 0.67 and 0.46 for Crohn’s disease (CD) and ulcerative colitis (UC), respectively.

Pooled analyses also showed that medium and high vs low vegetable intake at age 1 were tied to reduced IBD risk (pooled HRs, 0.66 [medium] and 0.72 [high]). “It has been hypothesized that intake of vegetables and vegetable fibres may have programming effects on the immune system, reducing IBD risk,” the researchers explained.

No association at 3yo

Only fish intake was associated with a reduction in the risk of later IBD, particularly UC, by age 3 (pooled aHR in model 1, 0.46).

According to the researchers, the lack of association between dietary habits at this age and later IBD risk implies that the impact of diet on IBD risk may be age dependent. “Since the gut microbiome seems to develop very early in life, diet at 1 year rather than at 3 years may have a stronger impact on the microbiome.”

Early-life diet vital for IBD development

“Although diet in early life is critical for the development of the gut microbiome and gut immune tolerance, diet has primarily been assessed in adulthood and few studies have assessed childhood diet in IBD risk,” the researchers noted.

The team used data from two parallel birth cohorts that were largely similar in design and data characteristics – ABIS and MoBa. A total of 81,280 children (~50 percent girls) with any food data recorded at age 1 and 65,692 children with any food data recorded at age 3 were included. Median follow-up time from age 1 was 21.3 years in ABIS and 15.2 years in MoBa.

During 1,304,433 person-years of follow-up, 307 children were diagnosed with IBD. A majority had CD (n=131), 97 had UC, while 79 had IBD-unclassified.

“While noncausal explanations for our results cannot be ruled out, these novel findings are consistent with the hypothesis that early-life diet, possibly mediated through changes in the gut microbiome, may affect the risk of developing IBD,” the researchers said.

The results highlight the role of early-life diet in IBD development and support more research that could further shed light on the role of diet in IBD prevention, they added.

Dr Ashwin Ananthakrishnan from Massachusetts General Hospital, Boston, Massachusetts, US, pointed out however that the questionnaires used did not capture other things, such as baby food components that might factor in the development of IBD. Nonetheless, a preventive diet for infants would be advisable given its potential health benefits. [Gut 2024;73:559-560]

“Despite the absence of gold standard interventional data demonstrating a benefit of dietary interventions in preventing disease, in my opinion, it may still be reasonable to suggest such interventions to motivated individuals that incorporate several of the dietary patterns associated with lower risk of IBD from this and other studies,” Ananthakrishnan said.