Western diets

An inverse correlation between thyroid cancer risk and phytoestrogens was recently proposed as a result of a multi-ethnic population-based case control study conducted in the San Francisco Bay Area (Hom-Ross et al., 2002). In this study, dietary habits and phytoestrogen consumption were assessed by a food-frequency questionnaire and by a nutrient database. The outcome of the study was that soy-based foods and alfalfa sprouts were associated with a reduction of thyroid cancer risk, whereas a Western diet did not influence cancer risk. No difference was observed between American and Asian women or between pre- and postmenopausal women. Furthermore, among the few compounds examined, the isoflavones genistein and daidzein and the lignan secoisolariciresinol were the phytoestrogens most frequently associated with risk reduction (Horn-Ross et al., 2002). 

An attempt to estimate human daily impact of N nitroso compounds is shown in Table I. The apparent intake from food of preformed nitrosamines is comparatively low, at least in these surveys of a Western diet in England (3). The Intake directly to the respiratory tract from smoking could be somewhat larger. However, if the blood levels reported are confirmed as correct, then inputs of up to 700 meg per day of at least N nitrosodimethylamine (NDMA) may be calculated, based on pharmacokinetic considerations of data obtained in animals and extrapolated to man. It should be emphasized that no information is available at present on nitrosamide intake or in vivo formation, largely because of analytical limitations. 

Experimental and epidemiologic evidence suggests an association between breast cancer and the Western diet (high in calories, fat, and cooked meats). Obesity in postmenopausal... 

About 90 g of protein is ingested each day by an adult on a typical Western diet and a similar amount enters the intestine from the secretion of enzymes, proteins and from sloughed epithelial cells (Chapter 8). The proteins are hydrolysed by proteolytic enzymes. 

The packaging of triacylglycerol into chylomicrons or VLDL provides an effective mass-transport system for fat. On a normal Western diet, approximately 400 g of triacylglycerol is transported through the blood each day. Since these two particles cannot cross the capillaries, their triacylglycerol is hydrolysed by lipoprotein lipase on the luminal surface of the capillaries (see above). Most of the fatty acids released by the lipase are taken up by the cells in which the lipase is catalytically active. Thus the fate of the fatty acid in the triacylglycerol in the blood depends upon which tissue possesses a catalytically active lipoprotein lipase. Three conditions are described (Figure 7.23) ... 

Oxidation plus gluconeogenesis Most but not aU amino acids are catabolised in the liver. Perhaps somewhat surprisingly, the amount of ATP generated from the oxidation of the amino acids derived from ingested protein on a normal Western diet usually exceeds the amount of ATP... 

On an average Western diet, adnlt hnmans excrete around 30 g of nrea per day but this can easily triple on a protein-rich diet. The reactions and the concept of a cycle were discovered by Krebs Henseleit (1932). Snbseqnent work clari-hed the details of what has become known as the ornithine or the nrea cycle. 

Richter, F., Newmark, H. L., Richter, A., Leung, D., and Lipkrn, M. (1995). Inhibition of Western-diet induced hyperproliferation and hyperplasia in mouse colon by two sources of calcium. Carcinogenesis 16, 2685-2689. 

About ten percent of the calories contained in the Western diet are supplied by fructose (approximately fifty g/day). The major source of fructose is the disaccharide sucrose, which, when cleaved in the intestine, releases equimolar amounts of fructose and glucose (see p. 86). Fructose is also found as a free monosaccharide in high-fructose corn syrup (55 percent fructose/45 percent glucose, which is used to sweeten most cola drinks), in many fruits, and in honey. Entry of fructose into cells is not insulin-dependent (unlike that of glucose into certain tissues, see p. 95), and, in contrast to glucose, fructose does not promote the secretion of insulin. 

Amino acids are quantitatively the most important source of ammonia, because most Western diets are high in protein and provide excess amino acids, which are deaminated to produce ammonia. Hoi/vever, substantial amounts of ammonia can be obtained from other soirees. 

LDL—but little change in HDL—when compared with a typical Western diet higher in saturated fats. Plasma triacylglycerols are unchanged. 

Flavan-3-ols represent the most common flavonoid consumed in the American and, most probably, the Western diet and are regarded as functional ingredients in various beverages, whole and processed foods, herbal remedies, and supplements. Their presence in food affects quality parameters such as astringency, bitterness, sourness, sweetness, salivary viscosity, aroma, and color formation [Aron and Kennedy, 2007]. Flavan-3-ols are structurally the most complex subclass of flavonoids ranging from the simple monomers ( + )-catechin and its isomer (—)-epicatechin to the oligomeric and polymeric proanthocyanidins (Fig. 1.10), which are also known as condensed tannins [Crozier et al., 2006b]. 

The many diverse components of milk have demonstrable effects on human health. Perhaps, the most commonly associated component of dairy food is that of dietary calcium. Dairy products provide the most significant contribution to dietary calcium intake in the modem Western diet. It has been estimated that dairy products contribute to >72% of dietary calcium in the United States (Huth et al., 2006). Calcium is an important mineral for maintenance of optimal bone health (Bonjour et al., 2009) and is an integral component of key metabolic pathways relating to, for example, muscle contraction both in skeletal and smooth muscle (Cheng and Lederer, 2008). Further, dairy products contribute other essential nutrients in the diet, such as proteins, phosphorus, potassium, zinc, magnesium, selenium, folate, riboflavin, vitamin B12, and vitamin A (Haug et al., 2007 Huth et al., 2006). Low-fat milk alternatives are fortified with vitamin A and vitamin D which is added to milk and fermented milk in many countries making it an important source for vitamin D (Huth et al., 2006). 

The decreased consumption of DHA-enriched foods and increased consumption of n-6 enriched vegetable oils is responsible for the 15 1 n-6 n-3 ratio (Wey-landt and Kang, 2005 Simopoulos, 2006). The present western diet promotes the pathogenesis of many chronic diseases such as cardiovascular disease, inflammatory and autoimmune diseases, and neurodegenerative diseases, whereas a diet enriched... 

Cordain L., Eaton S. B., Sebastian A., Mann N., Lindeberg S., Watkins B. A., O Keefe J. H., and Brand-Miller J. (2005). Origins and evolution of the Western diet health implications for the 21st century. Am. J. Clin. Nutr. 81 341-354. 

Osteoporosis is a disease or metabolic disturbance, particularly in postmenopausal women, that indicates a need for a very high dietary calcium intake. High calcium requirements appear to be related to the very high protein intake of the modem Western diet. A decreased protein intake, as can be obtained on a total vegetarian (vegan) diet, can allow for calcium balance, in a variety of age groups, from one third to one fifth the amount of daily calcium required with a Western diet. 

Within the last decade, the health benefits of ALA have been documented in numerous studies and may be related to an improved n-6 to n-3 fatty acid intake. Nettleton (2003) summarized the recommendations of leading health organizations regarding the proper ratio of n-6 to n-3 fatty acid intake. Most organizations agree that a 5 1 to 10 1 n-6 to n-3 fatty acid ratio is preferred (Institute of Medicine, 2002 WHO/FAO, 2003). However, a typical western diet has an n-6 to n-3 fatty add ratio well beyond 10 1 thus, flaxseed can be a valuable lipid source to improve the n-6 to n-3 fatty acid ratio due to the high n-3 content of flaxseed oil. 

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