Enterolignans (
enterodiol and
enterolactone) can potentially reduce the risk of certain
cancers and
cardiovascular diseases. Enterolignans are formed by the intestinal microflora after the consumption of plant
lignans. Until recently, only
secoisolariciresinol and
matairesinol were considered enterolignan precursors, but now several new precursors have been identified, of which
lariciresinol and
pinoresinol have a high degree of conversion. Quantitative data on the contents in foods of these new enterolignan precursors are not available. Thus, the aim of this study was to compile a
lignan database including all four major enterolignan precursors. Liquid chromatography-tandem mass spectrometry was used to quantify
lariciresinol,
pinoresinol,
secoisolariciresinol and
matairesinol in eighty-three solid foods and twenty-six beverages commonly consumed in The Netherlands. The richest source of
lignans was flaxseed (301,129 microg/100 g), which contained mainly
secoisolariciresinol. Also,
lignan concentrations in sesame seeds (29,331 microg/100 g, mainly
pinoresinol and
lariciresinol) were relatively high. For grain products, which are known to be important sources of
lignan,
lignan concentrations ranged from 7 to 764 microg/100 g. However, many vegetables and fruits had similar concentrations, because of the contribution of
lariciresinol and
pinoresinol. Brassica vegetables contained unexpectedly high levels of
lignans (185-2321 microg/100 g), mainly
pinoresinol and
lariciresinol.
Lignan levels in beverages varied from 0 (cola) to 91 microg/100 ml (red wine). Only four of the 109 foods did not contain a measurable amount of
lignans, and in most cases the amount of
lariciresinol and
pinoresinol was larger than that of
secoisolariciresinol and
matairesinol. Thus, available databases largely underestimate the amount of enterolignan precursors in foods.