Content of lignan, cadmium and some other chemical components in linseed and oil hemp varieties in south-western part of Finland

Summary

Lignans are phytoestrogens found ubiquitously throughout the plant kingdom and thus are also
present in our diet. After ingestion lignans go through various transformations and in the end
they form mammalian lignans by microbial conversion. The amount of these mammalian lignans
in human body is linked to the reduced risk of various hormonal dependent cancers such as
breast cancer. Flaxseed (Linum usitatissimum L.) is one of the richest sources of lignans used in
the human diet. Unfortunately, flaxseed also picks up cadmium very efficiently from the soil,
which has to be kept in mind when choosing what regions to cultivate it in. SDG-lignan,
cadmium and lead contents were studied in linseed, flax and oil hemp variety samples. Oil
hemp samples were seeds of the very low THC cannabinoid variety Finola. Linseed varieties
were Helmi, Heljä, Laser, Abacus and Sunrise and flax varieties were Martta and Belinka. Both
farm and trial samples were studied. SDG lignan contents of linseed and flax variety samples
varied 4840-9560 mg kg-1. Helmi linseed variety had higher SDG lignan content than that of
Laser. Cadmium contents of linseed and flax variety samples varied from 0.36-1.11 mg kg-1.
Cadmium contents of oil hemp samples were 0.017 mg kg-1 and 0.023 mg kg-1. Lead
concentrations were rather low in all samples. There was wide variation in the cadmium content
of linseed samples cultivated at different locations. It is important to cultivate linseed at high pH
soils with low heavy metal content, in order to prevent cadmium accumulation.