Urinary isoflavone kinetics: the effect of age, gender, food matrix and chemical composition

Faughnan, Marian S.; Hawdon, Ann; Ah-Singh, Eric; Brown, Jonathan E.; Millward, D. J.; Cassidy, Aedín

doi:10.1079/bjn20041087

Cited by 65 publications

(79 citation statements)

References 35 publications

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“…No difference has been found in the pharmaco-kinetics of either genistein or daidzein between pre-and postmenopausal women (Setchell et al 1997(Setchell et al , 2003aLu & Anderson, 1998;Faughnan et al 2004).…”

Section: Bioavailability and Sourcesmentioning

confidence: 99%

Critical review of health effects of soyabean phyto-oestrogens in post-menopausal women

et al. 2006

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A consensus view of soyabean phyto-oestrogens in clinical interventions in post-menopausal women is presented that is based on data from the EU-funded project Phytohealth. The phytooestrogens, primarily genistein and daidzein, were given as soyabean-protein isolates, wholesoyabean foods or extracts, supplements or pure compounds. A comprehensive literature search was conducted with well-defined inclusion or exclusion criteria. For areas for which substantial research exists only placebo-controlled double-blind randomised controlled trials (RCT) conducted on healthy post-menopausal women were included. For emerging areas all available human studies in post-menopausal women were reviewed. In order to make cross comparisons between studies the doses of isoflavones were calculated as aglycone equivalents. There is a suggestion, but no conclusive evidence, that isoflavones from the sources studied so far have a beneficial effect on bone health. The consumption of whole-soyabean foods and soyabeanprotein isolates has some beneficial effects on lipid markers of cardiovascular risk. The consumption of isolated isoflavones does not affect blood lipid levels or blood pressure, although it may improve endothelial function. For menopausal symptoms there is currently limited evidence that soyabean-protein isolates, soyabean foods or red-clover (Trifolium pratense L.) extract are effective but soyabean isoflavone extracts may be effective in reducing hot flushes. There are too few RCT studies to reach conclusions on the effects of isoflavones on breast cancer, colon cancer, diabetes or cognitive function. The health benefits of soyabean phytooestrogens in healthy post-menopausal women are subtle and even some well-designed studies do not show protective effects. Future studies should focus on high-risk post-menopausal women, especially in the areas of diabetes, CVD, breast cancer and bone health. The current interest in soyabean and its phyto-oestrogen component in relation to human health has resulted in a substantial number of publications on the potential clinical efficacy of these compounds to improve health in menopausal women. However, although numerous reviews have been presented, to date a consensus on the potential importance of these compounds for menopausal health following a critical grading of the studies and their results has not been conducted. The focus of the current review is specifically to grade the evidence from clinical studies addressing the effects of intervention of soyabean isoflavones (for chemical structures of the aglycones, seeAbbreviations: RCT, randomised controlled trial; SPI, soyabean-protein isolate.

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Section: Bioavailability and Sourcesmentioning

confidence: 99%

Critical review of health effects of soyabean phyto-oestrogens in post-menopausal women

et al. 2006

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“…This supports the likely influence of the markedly different GI microflora in newborn and weaned swine on production of IFN metabolites. Age, gender, and food matrix also have been reported to moderately affect urinary excretion of IFN in humans [47]. Other factors such as fermentable carbohydrate in the diet also may influence the production of IFN metabolites [48].…”

Section: Discussionmentioning

confidence: 98%

Gastrointestinal absorption and metabolism of soy isoflavonoids in ileal‐canulated swine

Walsh¹,

Fastinger²,

Bohn³

et al. 2009

Molecular Nutrition Food Res

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The relative contribution of the small intestine to absorption and microbial metabolism of ingested isoflavonoids (IFN) was investigated in swine with canulae in distal ilea to facilitate collection of chyme (canula open). Weaned swine were fed a single meal containing ground roasted soybean and corn with canulae open followed by a second test soy diet at 48 h with canulae closed to allow passage of chyme into the large intestine. All remaining feedings were soy-free (corn-casein diet). Ileal effluent and urine were collected for 16 and 48 h, respectively, and analyzed for IFN and microbial metabolites of IFN. IFN in ileal effluent were present entirely as aglycones. IFN equivalents excreted for 24 h after ingesting the soy diet were not significantly different when canulae were open or closed. Urinary IFN aglycone equivalents on day 2 were similar to those on day 1 when canulae remained closed, but less than 10% of that on day 1 when canulae were open for 16 h postfeeding. Urinary concentrations of dihydrodaidzein, dihydrogenistein, O-desmethylangolensin, and equol exceeded IFN aglycone equivalents. These findings suggest extensive preabsorptive conversion of IFN glucosides to aglycones in the small intestine and relatively efficient microbial metabolism of IFN in weaned swine.

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“…Besides, food matrix and chemical composition may affect the genistein absorption. It has been demonstrated that the fractional absorption of genistein is potentially different in men and women and is influenced by the food matrix and chemical composition 15 . In contrast, Richelle et al investigated…”

Section: Absorption Of Isoflavonesmentioning

confidence: 99%

Effects of Intestinal Flora on the Metabolism and Absorption of Isoflavones

Tamura

2006

JARQ

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Soybean and soy foods are rich sources of isoflavones. Much attention has focused on isoflavonoids because of their beneficial effects on human health. Isoflavones belong to the group of phytoestrogens. Phytoestrogens are estrogenic compounds found in plants. Intestinal flora plays an important role in the absorption and metabolism of isoflavones. Some dietary components and chemical composition of isoflavones are also known to affect the absorption of isoflavones. Human metabolism and excretion of isoflavones following the consumption of soy products show considerable variation. The bioavailability of soybean isoflavones to women is dependent on gut microflora. Equol is a metabolite of daidzein produced by intestinal flora. Equol has many biological activities related to human health, and its production might be affected by compositions of diets and intestinal flora. To achieve higher production of equol from daidzein in the gut, control of the metabolic activity of intestinal flora might be of importance.

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Urinary isoflavone kinetics: the effect of age, gender, food matrix and chemical composition

Cited by 65 publications

References 35 publications

Critical review of health effects of soyabean phyto-oestrogens in post-menopausal women

Critical review of health effects of soyabean phyto-oestrogens in post-menopausal women

Gastrointestinal absorption and metabolism of soy isoflavonoids in ileal‐canulated swine

Effects of Intestinal Flora on the Metabolism and Absorption of Isoflavones

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