Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.

Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare or...

Full description

Bibliographic Details
Main Authors: Steffen A Adler, Stig Purup, Jens Hansen-Møller, Erling Thuen, Håvard Steinshamn
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0127187
_version_ 1818682559986401280
author Steffen A Adler
Stig Purup
Jens Hansen-Møller
Erling Thuen
Håvard Steinshamn
author_facet Steffen A Adler
Stig Purup
Jens Hansen-Møller
Erling Thuen
Håvard Steinshamn
author_sort Steffen A Adler
collection DOAJ
description Phytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans.
first_indexed 2024-12-17T10:20:47Z
format Article
id doaj.art-6cc7b83458ae4cb7916d056b5bf712ae
institution Directory Open Access Journal
issn 1932-6203
language English
last_indexed 2024-12-17T10:20:47Z
publishDate 2015-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj.art-6cc7b83458ae4cb7916d056b5bf712ae2022-12-21T21:52:48ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01105e012718710.1371/journal.pone.0127187Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.Steffen A AdlerStig PurupJens Hansen-MøllerErling ThuenHåvard SteinshamnPhytoestrogens have structures similar to endogenous steroids and may induce or inhibit the response of hormone receptors. The objectives of the present study were to compare the effects of long-term vs. short-term grassland management in organic and conventional dairy production systems, compare organic and conventional production systems and assess seasonal variation on phytoestrogen concentrations in bulk-tank milk. The concentrations of phytoestrogens were analyzed in bulk-tank milk sampled three times in two subsequent years from 28 dairy farms: Fourteen organic (ORG) dairy farms with either short-term or long-term grassland management were paired with 14 conventional (CON) farms with respect to grassland management. Grassland management varied in terms of time since establishment. Short-term grassland management (SG) was defined as establishment or reseeding every fourth year or more often, and long-term grassland management (LG) was defined as less frequent establishment or reseeding. The proportion of red clover (Trifolium pretense L.) in the herbage was positively correlated with milk concentrations of the mammalian isoflavone equol. Therefore, organically produced bulk-tank milk contained more equol than conventionally produced milk, and milk from ORG-SG farms had more equol than milk from ORG-LG farms. Milk produced during the indoor-feeding periods had more equol than milk produced during the outdoor feeding period, because pastures contained less red clover than fields intended for silage production. Organically produced milk had also higher concentrations of the mammalian lignan enterolactone, but in contrast to equol, concentrations increased in the outdoor-feeding periods compared to the indoor-feeding periods. There were no indications of fertility problems on ORG-SG farms who had the highest red clover proportions in the herbage. This study shows that production system, grassland management, and season affect milk concentrations of phytoestrogens. However, compared to soy products, milk concentrations of phytoestrogens are low and future studies are required to investigate if the intake of phytoestrogens from dairy products has physiological effects in humans.https://doi.org/10.1371/journal.pone.0127187
spellingShingle Steffen A Adler
Stig Purup
Jens Hansen-Møller
Erling Thuen
Håvard Steinshamn
Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
PLoS ONE
title Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
title_full Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
title_fullStr Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
title_full_unstemmed Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
title_short Phytoestrogens and their metabolites in bulk-tank milk: effects of farm management and season.
title_sort phytoestrogens and their metabolites in bulk tank milk effects of farm management and season
url https://doi.org/10.1371/journal.pone.0127187
work_keys_str_mv AT steffenaadler phytoestrogensandtheirmetabolitesinbulktankmilkeffectsoffarmmanagementandseason
AT stigpurup phytoestrogensandtheirmetabolitesinbulktankmilkeffectsoffarmmanagementandseason
AT jenshansenmøller phytoestrogensandtheirmetabolitesinbulktankmilkeffectsoffarmmanagementandseason
AT erlingthuen phytoestrogensandtheirmetabolitesinbulktankmilkeffectsoffarmmanagementandseason
AT havardsteinshamn phytoestrogensandtheirmetabolitesinbulktankmilkeffectsoffarmmanagementandseason