Dietary factors milk diet

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. 

Infants require a substantial supplementation of AA, which is normally supplied through breast milk. Almost 10% of the membrane phospholipid content of breast fed infants was found to be AA in one study (Koletzko et ah, 1996). A crucial factor of the developing infant brain is the amount and type of polyunsaturated fatty acids they receive from their diet. That is, the ratio of dietary n-3 fatty acids (those in which the unsaturation begins 3 carbons from the terminal carbon) to n-6 fatty acids can be optimized to... 

Both the active and passive modes of calcium transport are increased during pregnancy and lactation. This is probably due to the increase in calbindin and serum PTH and 1,25-dihydroxyvitamin D concentrations that occur during normal pregnancy. Intestinal calcium absorption is also dependent on age, with a 0.2% per year decline in absorption efficiency starting in midlife. The fractional absorption of calcium depends on the form and dietary source. Absorption rates are 29% for the calcium in cow s milk, 35% for calcium citrate, 27% for calcium carbonate, and 25% for tricalcium phosphate. Other factors that limit the bioavailability of calcium in the intestine are oxalates and phy-tates, which are found in high quantities in vegetarian diets and which chelate calcium. 

Animal products contain important nutrients in bioavailable form, essential for growth and proper physical and mental development. Milk and milk products are the major source of essential nutrients in diet. Thus, knowledge of the mineral concentrations in milk samples and milk products is of particular interest. This becomes especially important in view of the wide variability in mineral content of milk due to numerous factors affecting milk composition, such as lactation (the composition of milk varies considerably during lactation, with the major changes usually occurring soon after the start of the lactation period), the breed of animal, climate, season, dietary composition of animal feed and soil contamination. Also, the mineral content may vaiy because of its handling by humans. ... 

In addition to seasonal factors, significant changes in the FA composition of milk fat can be achieved by manipulating the cow s diet. Milk fat composition is influenced more by dietary fat than by any other dietary component. The effects of fat supplementation on FA composition are dependent on the type and amount of dietary fat. In most cases, fat supplements decrease the proportions of 6 0 to 14 0 acids (de novo synthesized) and increase the proportion of long-chain (dietary) FA. Diets containing supplemental fat do not affect the proportion of C4 0 in milk fat. 

Under psycho-physical, dietary, and environmental stress conditions, or after medication intake, there is an imbalance of microflora that makes the body susceptible to attack by pathogens. A proper diet is one of the main factors that influence the qualitative and quantitative composition of intestinal microflora. The most common approach involves the consumption of traditional foods, such as yogurt and fermented milk, which essentially contain probiotics, defined as live microorganisms, which can positively affect the host by improving its intestinal microbial balance. 

Research to determine the benefits of CLA for humans will present a unique challenge in the next few years. It will certainly require the improved and complementary methods of CLA and trans FA analysis to evaluate the biological effects of dietary supplements to determine the true effects of CLA in humans. In some studies the presence of CLA in human bodies and those produced by bacteria in the gut may need to take into consideration. The CLA research to date in humans has focused mainly on the effects of rl0,fl2-18 2 rather than on c9,t 1-18 2, the major CLA isomer present in the milk and meat of ruminants. This would appear to be due to the readily available source of commercial CLA preparations compared to pure c9,tl 1-18 2. Commercial CLA preparations consist of an equal mixture of t 0,c 2-18 2 and c9,rl 1-18 2. On the other hand, the rl0,cl2-18 2 isomer is generally present only in trace amounts in milk fats, while some ruminant fats may contain more of the CLA isomers. The true response, if any, of c9,fl 1-18 2 in humans remains to be determined. Several cohort studies have shown a significant reduction in risk factors associated with the consumption of diets high in dairy products and certain types of cancers but not with others. It remains to be seen if the benefits were due to c9,rl 1-18 2, other components in dairy products, or synergistic processes. Regardless of whether CIA s apparent benefits can be translated to humans, it is likely that CLA, as a model test object, will be used in the future in many more studies related to major maladies such as cancer, atherosclerosis, diabetes, etc. 

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