Age-dependency in the metabolism of flaxseed lignans by healthy adults

Flaxseed lignan metabolites, enterodiol (END) and enterolactone (ENL), have biological activities that may have potential therapeutic benefit through their antioxidative and oestrogenic properties. Circulating enterolignan concentrations are influenced by gut bacteria, which itself is subject to change with age. The plasma availability of END, ENL and total enterolignans (END + ENL) after 0 and 4-weeks of dietary milled flaxseed consumption (30 g/d) in healthy, younger (18-29 years) and older (45-69 years) adults was determined by using gas chromatography/mass spectrometry. Plasma total enterolignan concentrations increased in both younger and older adults, however, the distribution of END:ENL was lower in older adults (0.74) compared to younger adults (0.96). Post flaxseed treatment, ENL was detected in the plasma of 100% of the older adults, but only in 78% of the younger ones. The potential therapeutic benefit offered by enterolignans may be particularly important for ageing populations that are prone to chronic diseases.