Dietary factors effect

Several studies have investigated the role of dietary factors in prostate cancer risk, but results appear inconsistent. Significant effects have not been detected for dietary soya products certain vegetables, beans, fruit, rice and seaweed appear to be protective in some studies, while another has shown no protective effect from seaweed or vegetable consumption. In addition, a number of other risk factors have been shown to be associated with an increased risk of this cancer, including meat and dairy products and carotenoids. 

Mortality rates from CVD are generally lower in Asian populations compared to Western populations (Knight and Eden, 1996). Although many dietary factors are known to play a protective role in CVD and it has been suggested that phytoestrogen content of Asian diets may be responsible for the cardioprotective effect. 

In summary, the true association between most dietary factors and the risk of colon cancer is unclear. The protective effects of fiber, calcium, and a diet low in fat are not completely known. Lifestyle factors such as NSAID use and hormone use appear to decrease the risk of colorectal cancer, whereas physical inactivity, alcohol use, and smoking appear to increase the risk of colon cancer. Clinical risk factors and genetic mutations are well-known risks for colon cancer. 

Other dietary factors implicated in prostate cancer include retinol, carotenoids, lycopene, and vitamin D consumption.5,6 Retinol, or vitamin A, intake, especially in men older than age 70, is correlated with an increased risk of prostate cancer, whereas intake of its precursor, [3-carotene, has a protective or neutral effect. Lycopene, obtained primarily from tomatoes, decreases the risk of prostate cancer in small cohort studies. The antioxidant vitamin E also may decrease the risk of prostate cancer. Men who developed prostate cancer in one cohort study had lower levels of l,25(OH)2-vitamin D than matched controls, although a prospective study did not support this.2 Clearly, dietary risk factors require further evaluation, but because fat and vitamins are modifiable risk factors, dietary intervention may be promising in prostate cancer prevention. 

Many other dietary factors have been reported to affect calcium bioavailability. Phytate, fiber, cellulose, uronic acids, sodium alginate, oxalate, fat (only in the presence of steatorrhea), and alcohol have been reported to decrease calcium bioavailability (15). Lactose and medium chain triglyceride increase it (15). FTuoride also affects calcium retention primarily by stimulating bone formation thereby decreasing calcium excretion (33-38). The effects of fluoride on calcium utilization have been variable (34,38,39). 

Chinn, H.I. "Effects of Dietary Factors on Skeletal Integrity... 

Tsuchiya H, Nagayama M, Tanaka T et al. Membrane-rigidifying effects of anti-cancer dietary factors. Biofactors 16 (3-4), 45-56, 2002. 

Chinn, H. I. 1981. Effects of Dietary Factors on Skeletal Integrity in Adults Calcium, Phosphorus, Vitamin D, and Protein. Life Sciences Research Office, Federation of American Societies for Experimental Biology, Bethesda, Md. 

Another possible dietary factor concerns the essential fatty acid content of human and artificial milk. It has been postulated by Sinclair that many modern dietaries are deficient in the essential polyethenoid fatty acids (EFA) and that in consequence there is a rise in unesterified (and more active) vitamin D and in unesterified cholesterol. He has suggested that a part of the etiology of infantile idiopathic hypercalcemia may be attributed to EFA deficiency (S5). He has pointed to the lower content of certain unsaturated fatty acids in cow s milk as compared with human milk as a factor in the development of idiopathic hypercalcemia in artificially fed infants. He considers that dried milk has an even lower content of essential fatty acids than liquid cow s milk and that the longer it is stored the lower does the essential fatty acid content become. On the basis of some observations on rats, he suggests that a dietary deficiency of the essential fatty acids increases susceptibility to the possible toxic effects of vitamin D. The age of the rats, the duration of the essential fatty acid deficient diet, or the dosage of vitamin D is not mentioned, and there would appear to be no other experimental data to support these views. 

Effect of Dietary Factors on Drug Disposition in Normal Human Subjects... 

Figure 1 This circular design suggests the possibility of dynamic interactions among the several well-established or suspected dietary factors that may influence drug response in humans. Arrows from each factor in the outer circle are wavy to indicate that effects of each dietary factor on drug response may occur at multiple sites and through different processes. The inner circle suggests that effects of dietary factors may be modified by many other environmental, as well as by genetic, factors.

Studies on starvation, however, are compatible with a major effect of changing the proportion of the macromolecular constituents of isocaloric diets. This reconciliation of seemingly contradictory results offers an opportunity to stress the complex effects of several dietary factors and the possibility for interactions among them. 

The epidemiologic data, relative to dietary fiber, has been supported by animal studies but experiments with dietary fat have been conflicting and generally do not indicate a fat effect. Other dietary factors which associate with colon cancer in animal studies are deficits of lipotropes and of vitamin A. 

Absorption in rat liver, conjugated diene, various choline diets, 332f Absorption spectrum of the DNA adduct and reaction mixture, 105 Acetaminophen, effect of dietary factors on metabolism, 62... 

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