Dietary intake of phytoestrogens

Tapparelli, C., Mettemich, R., Ehrhardt, C., Zurini, M., Claeson, G., Scully, M.F., Stone, S.R. In vitro and in vivo characterization of a neutral boron-containing thrombin inhibitor. J. Biol. Chem. 1993 268 4734-4741. Touillaud, M.S., Pillow, P.C., Jakovljevic, J., Bondy, M.L., Singletary, S.E., Li, D., Chang, S. Effect of dietary intake of phytoestrogens on estrogen receptor status in premenopausal women with breast cancer. Nutr. Cancer. 2005 51 162-169. 

Calculation of the dietary intakes of estrogenic pesticides compared to the intakes of natural phytoestrogens present in soya and other legumes clearly shows that pesticides represent a drop in the ocean of dietary xenoestrogen intake (Table 10.3) (Shaw and McCully, 2000). 

It has been shown that in postmenopausal women habitually high intakes of dietary isoflavones are associated with higher bone mineral density (BMD) values at both the spine and hip region (Mei et al, 2001). It is conceivable that an isoflavone-rich diet may help to reverse the state of secondary hyperparathyroidism associated with estrogen withdrawal and hence lower the rate of bone turnover in postmenopausal women, thus reducing the risk of osteoporosis (Valtuena et al, 2003). Phytoestrogens could be used as natural SERMs (Brzezinski and Debi, 1999) and some studies (Setchell, 2001 and refs therein) support such an idea since the molecular targets of... 

Arai Y, Uehara M, Sato Y, Kimira M, Eboshida A, Adlercreutz H, Watanabe S. 2000. Comparison of isoflavones among dietary intake, plasma concentration and urinary excretion for accurate estimation of phytoestrogen intake. J Epidemiol 10 127-135. 

Isoflavones are a class of phytoestrogens with estrogenic activity. They are related to isoflavonoids. Isoflavones are produced almost exclusively by members of the Fabaceae (Leguminosae) family. Soy products and soybeans are the richest sources of isoflavones that humans consiune [43]. Recent surveys suggest that the average dietary isoflavone intake in Asian countries ranges from 25-50 mg/day [44]. Dietary isoflavone intakes are considerably lower in Western countries, where on average intake is as low as 2 mg/day. Soy products that are... 

Other Diseases. Although lacking a definitive basis, it has been suggested that dietary practice, and hence potentially phytoestrogen intake, may play a modifying role in the incidence of a number of other disease conditions. 

In most studies, phytoestrogen intake has been estimated by direct methods that evaluate food intake either by recall (food-frequency questionnaires -FFQs) or by record (food diary), and subsequently by composition databases based on information of this kind. Food-frequency questionnaires are widely administered to subjects involved in epidemiological studies. Their validity and reproducibility is considered sufficient when statistically correlated to data obtained from dietary records (a properly-completed and comprehensive food diary) and from analysis of blood and urine samples (Kirk et ah, 1999 Huang et al, 2000 Yamamoto et al, 2001 Verkasalo et al, 2001). FFQs can be repeated several times a year and may be administered to large populations. Such an approach provides an easy and low-cost method of assessing the... 

Grace PB, Taylor JI, Low YL, Luben RN, Mulligan AA, Botting NP, Dowsett M, Welch AA, Khaw KT, Wareham NJ, Day NE, Bingham SA. 2004. Phytoestrogen concentrations in serum and spot urine as biomarkers for dietary phytoestrogen intake and their relation to breast cancer risk in European prospective investigation of cancer and nutrition-Norfolk. Cancer Epidemiol Biomark Prev 13 698-708. 

Dietary factors, such as fiber, vitamin B6, and phytoestrogen intake, and lifestyle factors such as exercise, smoking, and alcohol use, which are controlled for in most epidemiologic studies, do not explain the apparent protective effect of whole grains... 

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