Epidemiological studies isoflavones

The study on prostate cancer (Table 20.7) found no association between prostate cancer risk with any of the analyzed flavonoids [Bosetti et al., 2006]. Although some flavonoids showed a favorable effect against prostate cancer [Magee and Rowland, 2004], the results from epidemiological studies are inconsistent. A recent prospective study from Japan found that isoflavone... 

Epidemiological studies (Aldercreutz et al., 1991 Aldercreutz, 1998) indicate that consumption of tofu and other soy foods may be associated with the low incidence of breast cancer in Japanese women. This discovery has led numerous researchers in recent years to search for the biochemical components in soybean that are responsible for the cancer risk-lowering effect. Aside from the potential cancer prevention effect (Wu et al., 1996 Cline and Hughes, 1998 Griffiths et al., 1998 Messina and Bennink, 1998 Stephens, 1999), isoflavones also have been found to have other potential health benefits, including heart disease prevention (Anthony et al., 1998), bone mass density increase to prevent osteoporosis (Anderson and Camer, 1997) and the reduction of postmenopausal syndromes in women (Knight et al., 1996). 

Most of the support for the anticancer effects of isoflavones comes from epidemiological studies, for which data suggest that a diet rich in... 

From an epidemiological study, the intake of soy isoflavone supplements also could decrease the risk of the breast eaneer [10,11]. 

Considerable evidence exists from epidemiological and experimental studies for preventive effects of soy or isoflavones against chronic diseases including cancer (breast, prostate, colorectal, lung), osteoporosis, cardiovascular disorders, and menopausal symptoms, but this is not always consistent [Adlercreutz... 

Observations of lower rates of certain chronic diseases in several Asian countries compared to the United States served as the impetus for studies that were conducted to identify the factors that were accountable (Tham et al., 1998). Consumption of soy is one factor that correlated with these lower rates. From this information, much research focused on soy protein and accompanying bioactive compounds with regard to elucidating mechanisms associated with risk markers for chronic disease, particularly CVD. The combination of macro- (protein, fiber, fat) and micro-components (isoflavones, saponins, tocopherols) as part of many traditional soy foods may underlie the epidemiological observations associated with soy intake. A body of cell culture and animal data shows potential health effects of a multitude of bioactive components in soy (i.e., saponins, phenolic acids, peptides). However, studies determining the independent effects of saponins, phenolic acids, and protease inhibitors in humans are yet to be conducted. 

Isoflavonoids also have been reported to have physiological activity in animal and human studies. Besides acting as an estro n mimic, it was reported that the isoflavones found in soybean seeds possess antihemolytic, antifungal, tumorsuppressing, and serum cholesterol-lowering effects. In addition, both epidemiological and dietary-intervention studies indicate that when isoflavones in soybean seeds and in subsequent protein products prepared from the seeds are part of the human dietary intake, those products provide many significant health benefits. - ... 

Recently, these epidemiologic evidences and experimental data from animal studies [14-20] are highly suggestinig their benefrcial effects of isoflavones (2) on human health, however the supportive clinical data of such effects are either not available, or are awaiting the design and execution of appropriate large-scale clinical studies. Nevertheless, the data from limited small pilot studies are promising, and these data have spurred the current interest in this area [1, 13],... 

Despite the epidemiological evidence for beneficial health effects of soy consumption, the safety of soy and its constituent isoflavones has been questioned. Concerns have mairrly arisen from animal and in vitro studies, but also a few human intervention studies relating to BC risk, which suggest that isoflavones may be involved in estrogen-sensitive cancer development, th5Toid dysfunction, and reduced fertility. 

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