Lignan precursors are found in a wide variety of plant-based foods, including seeds, whole grains, legumes, fruit, and vegetables. Among food sources rich in lignans, whole grains receive more attention because they are staple foods of the human diet globally and also contain essential vitamins, minerals, dietary fiber, β-glucan, inulin, numerous phytochemicals, phytosterols, phytin, and sphingolipids.
Regarding cereal grains, lignans are largely concentrated in their outer layers. In cereal grains, the highest lignan concentration is found in the fiber-rich outer layers (seed coat and pericarp), as well as the aleurone layer, whereas the lowest concentration is found in the inner endosperm
The lignan content of foods is generally low and usually does not exceed 2 mg/100 g. The exceptions are flaxseed27 (335 mg/100g) and sesame seeds (373 mg/100g), which have a lignan content a hundred times higher than other dietary sources.
The lignans are a class of phytoestrogen and can be metabolized to the biologically active enterolignans, enterodiol, and enterolactone by a consortium of intestinal bacteria.
The lignans consumed by animals and humans are hydrolyzed and metabolized to the biologically active enterolignans, enterodiol, and enterolactone by a consortium of intestinal bacteria.These metabolites possess a chemical structure similar to a sex hormone in the estrogen family and can act as phytoestrogens.
Phytoestrogens may have either estrogenic or antiestrogenic effects. Most available research links phytoestrogens to a variety of health benefits. The phytoestrogens can positively affect cognitive functions, such as learning, attention, and short-term memory, as well as influence sensorimotor such as fine touch, smell, hearing, and motor activities.
The scientific literature for lignan bioactive food components has shown a spectrum of important biological and health promoting activities such as cancer chemoprevention, antioxidant and antiinflammatory properties, lipid-lowering effects, cardiovascular disease (CVD) protection, and antimicrobial actions as well as obesity and diabetes management.
The plant lignans most commonly distributed in foods are lariciresinol, matairesinol, pinoresinol, and secoisolariciresinol. Several other lignans are present in some foods, including medioresinol (in sesame seeds, rye, and lemons), syringaresinol (in grains), sesamin and the lignan precursor sesamolin (in sesame seeds).
Polyphenolic compound of lignans
