In the Special Turku Coronary Risk Factor Intervention Project (STRIP), 1116 children from the city of Turku, Finland, were randomly assigned to either an intervention group to receive an intervention aimed to reduce exposure to environmental cardiometabolic risk factors or to a control group at 7 months of age. Intervention continued until 20 years of age. Saturated fat intakes and LDL-cholesterol values were lower in the intervention group than in controls, but no untoward effects on growth or development were found. At 26 years of age, i.e., 6 years after the intervention period ended, the intervention effect was still seen, though it was slightly diluted. At that age, a higher proportion of intervention group participants met the ideal total cholesterol concentration of less than 5.17 mmol/L (81% vs 72%, p = 0.024) and optimal LDL cholesterol concentration of less than 3.0 mmol/L (69% vs 61%, p = 0.031). The STRIP study shows that early intervention aiming at the reduction of exposure to environmental cardiometabolic risk factors is both safe and effective.