Risk of acute coronary events according to serum concentrations of enterolactone: a prospective population-based case-control study

Background The lignan enterolactone, produced by the intestinal microflora from dietary precursors, has been implicated in protection against cancer. We investigated the association of serum enterolactone concentration with the risk of acute coronary events in a prospective nested case-control study in middle-aged men from eastern Finland. Methods Enterolactone was measured by time-resolved fluoroimmunoassay in serum from 167 men who had an average 7•7 years of follow-up to an acute coronary event and from 167 control men. Both cases and controls were from a cohort of 2005 men who had no clinical coronary heart disease (CHD) at baseline. The controls were matched for age, examination year, and residence. Acute coronary events were registered prospectively. Findings The mean baseline serum enterolactone concentration was lower among the cases than the controls (18•2 [SD 21•1] vs 23•5 [18•2] nmol/L, p=0•001). The men in the highest quarter of the enterolactone distribution (>30•1 nmol/L) had a 58•8% (95% CI 24•1–77•6, p=0•005) lower risk of acute coronary events than men in the lowest quarter. After adjustment for the nine most strongly predictive risk factors, men in the highest enterolactone quarter had a 65•3% (11•9–86•3, p=0•03) lower risk than men in the lowest quarter. Interpretation Healthy men with high serum concentrations of enterolactone had a lower risk of acute coronary events than men with lower concentrations. These findings support the hypothesis that plant-dominated fibre-rich food lowers the risk of CHD.