A major cohort study of more than 117,000 people has found that a healthier start to life is associated with a lower risk of developing inflammatory bowel disease (IBD) in early adulthood, with the strongest link seen for Crohn’s disease.
What the research looked at
Researchers examined participants from two Scandinavian birth cohorts born between 1997 and 2009, combining data on multiple early-life factors including exposure to tobacco smoke, mode of delivery, breastfeeding, diet quality, antibiotic use, physical activity and body mass index. By a mean age of 20 years, 0.6% of participants (732 individuals) had been diagnosed with an IBD.
The team created composite lifestyle scores to capture modifiable health-related behaviours in infancy and early childhood. They report that infants with a high score by age one had a lower later risk of IBD, and that similar protective associations were observed when the score was assessed at age three.
Key findings
- High early-life adherence to healthy behaviours by age 1 was associated with a reduced risk of later IBD (adjusted hazard ratio 0.77).
- The association was strongest for Crohn’s disease — an adjusted hazard ratio of 0.57 when the healthy-lifestyle score was high at age 1.
- High adherence by age 3 showed similar reductions in risk: IBD 0.77, Crohn’s disease 0.68.
- No meaningful link was observed between early-life lifestyle scores and risk of ulcerative colitis in this analysis.
"A healthy lifestyle in early childhood was associated with a reduced risk of IBD, particularly Crohn's disease, suggesting that early lifestyle modifications may help prevent the disease."
Numbers at a glance
| Measure | Result |
|---|---|
| Participants | 117,487 |
| Diagnosed with IBD by mean age 20 | 732 (0.6%) |
| Adjusted hazard ratio (IBD) — high score at age 1 | 0.77 |
| Adjusted hazard ratio (Crohn’s) — high score at age 1 | 0.57 |
| Adjusted hazard ratio (IBD) — high score at age 3 | 0.77 |
| Adjusted hazard ratio (Crohn’s) — high score at age 3 | 0.68 |
What this means for families
The study does not prove causation but strengthens the evidence that modifiable early-life factors could influence the risk of later inflammatory bowel conditions. For parents and carers, the research reinforces established public-health advice already promoted by NHS and paediatric bodies: avoid tobacco smoke exposure, support breastfeeding where possible, encourage nutritious diets and appropriate physical activity, and use antibiotics judiciously.
Clinicians and public-health planners may view the findings as further impetus to focus on early intervention and family support. Preventive measures that improve general child health could also have benefits for long-term gut health.
Limitations and next steps
The investigators used observational data from two birth cohorts and adjusted for known confounders, but residual confounding cannot be ruled out. The average follow-up reached young adulthood; longer-term follow-up would be needed to see whether associations persist into later life. Researchers also noted differences between types of IBD — with the observed protective link stronger for Crohn’s than for ulcerative colitis — suggesting distinct disease mechanisms.
Further studies could explore which specific early-life interventions are most effective and whether targeted public-health programmes can reduce IBD incidence at a population level.
For families wanting to adopt healthy early-life habits, the evidence supports established steps that are already recommended for child development and wellbeing, and which may confer the additional advantage of lowering the risk of certain inflammatory bowel diseases in later years.
