The Journal of nutrition
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The Journal of nutrition · Feb 2002
Comparative StudyPlasma homocysteine levels in Taiwanese vegetarians are higher than those of omnivores.
Mild hyperhomocysteinemia is an independent risk factor for cardiovascular disease and may result from a deficiency of folate, vitamin B-6 or vitamin B-12. Because vitamin B-12 deficiency is often associated with vegetarianism, this study was designed to examine the effect of Taiwanese vegetarian diets on B-vitamin status and plasma homocysteine levels. Female Buddhist lacto-vegetarians (n = 45; 31-45 y) and matched omnivores (n = 45) recruited in Hualien, Taiwan, were investigated. ⋯ Compared with the omnivores, vegetarians also had significantly lower serum levels of valine, isoleucine, leucine, lysine, alanine and arginine, but higher levels of glycine. In the vegetarian group, fasting plasma homocysteine correlated negatively with serum threonine, lysine, histidine, arginine and cystine, and these amino acids contributed to 38.7% of homocysteine variation. In conclusion, the Buddhist nuns who consumed a lacto-vegetarian diet had mildly elevated fasting plasma homocysteine levels presumably due to lower levels of plasma vitamin B-12.
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The Journal of nutrition · Nov 2001
Randomized Controlled Trial Clinical TrialEffects of iron and zinc supplementation in Indonesian infants on micronutrient status and growth.
In this study the effects of supplementation of iron and zinc, alone or combined, on iron status, zinc status and growth in Indonesian infants is investigated. Micronutrient deficiencies are prevalent in infants in developing countries, and deficiencies often coexist; thus, combined supplementation is an attractive strategy. However, little is known about interactions between micronutrients. ⋯ The growth of all groups was insufficient to maintain the same Z-scores for height for age and weight for height. There is a high prevalence of deficiencies of iron and zinc in these infants, which can be overcome safely and effectively by supplementation of iron and zinc combined. However, overcoming these deficiencies is not sufficient to improve growth performance in these infants.
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The Journal of nutrition · Nov 2001
ReviewThe Mediterranean diets: What is so special about the diet of Greece? The scientific evidence.
The term "Mediterranean diet," implying that all Mediterranean people have the same diet, is a misnomer. The countries around the Mediterranean basin have different diets, religions and cultures. ⋯ Analyses of the dietary pattern of the diet of Crete shows a number of protective substances, such as selenium, glutathione, a balanced ratio of (n-6):(n-3) essential fatty acids (EFA), high amounts of fiber, antioxidants (especially resveratrol from wine and polyphenols from olive oil), vitamins E and C, some of which have been shown to be associated with lower risk of cancer, including cancer of the breast. These findings should serve as a strong incentive for the initiation of intervention trials that will test the effect of specific dietary patterns in the prevention and management of patients with cancer.
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The Journal of nutrition · Nov 2001
Intracellular S-adenosylhomocysteine concentrations predict global DNA hypomethylation in tissues of methyl-deficient cystathionine beta-synthase heterozygous mice.
Because S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are the substrate and product of essential methyltransferase reactions; the ratio of SAM:SAH is frequently used as an indicator of cellular methylation potential. However, it is not clear from the ratio whether substrate insufficiency, product inhibition or both are required to negatively affect cellular methylation capacity. A combined genetic and dietary approach was used to modulate intracellular concentrations of SAM and SAH. ⋯ A decrease in SAM:SAH ratio was predictive of reduced methylation capacity only when associated with an increase in SAH; a decrease in the SAM:SAH ratio due to SAM depletion alone was not sufficient to affect DNA methylation in this model. Plasma homocysteine levels were positively correlated with intracellular SAH levels in all tissues except kidney. These results support the possibility that plasma SAH concentrations may provide a sensitive biomarker for cellular methylation status.
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Severe infection causes marked derangements in the flow of glutamine among organs, and these changes are accompanied by significant alterations in regional cell membrane transport and intracellular glutamine metabolism. Skeletal muscle, the major repository of glutamine, exhibits a twofold increase in glutamine release during infection, which is associated with a significant increase in endogenous glutamine biosynthesis. Despite an increase in glutamine synthetase activity in skeletal muscle, the intracellular glutamine pool becomes depleted, indicating that release rates exceed rates of synthesis. ⋯ Recent studies suggest that IGF-1 has a direct effect on stimulating glutamine transport across the gut lumen and thus may represent a therapeutic avenue for improving gut nutrition during severe infection. The cells of the immune system (lymphocytes, macrophages) are also major glutamine consumers during inflammatory states in which cell proliferation is increased. Under these conditions, glutamine availability can become rate limiting for key cell functions, such as phagocytosis and antibody production.