The Journal of nutrition
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The Journal of nutrition · Dec 2004
Long-term ovo-lacto vegetarian diet impairs vitamin B-12 status in pregnant women.
A well-planned vegetarian diet has been stated to be adequate during pregnancy. The aim of the present study was to compare serum vitamin B-12 and homocysteine concentrations in pregnant women (n = 109) consuming vegetarian and Western diets and to evaluate the adequacy of current dietary reference intakes of vitamin B-12 for these women. Pregnant women adhering to vegetarian diets for at least 3 y, with subgroups of ovo-lacto vegetarians (OLVs; n = 27), low-meat eaters (LME, n = 43), and women eating an average Western diet (control group, n = 39), were recruited. ⋯ Serum vitamin B-12 concentrations increased and plasma tHcy decreased sharply with increasing dietary intake of vitamin B-12 toward a cutoff point of 3 mug/d. Pregnant women consuming a long-term predominantly vegetarian diet have an increased risk of vitamin B-12 deficiency. Current recommended dietary intakes urgently need reevaluation.
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The Journal of nutrition · Nov 2004
Methionine synthase reductase 66A->G polymorphism is associated with increased plasma homocysteine concentration when combined with the homozygous methylenetetrahydrofolate reductase 677C->T variant.
Methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) are important for homocysteine remethylation. This study was designed to determine the influence of genetic variants (MTHFR 677C-->T, MTHFR 1298A-->C, and MTRR 66A-->G), folate, and vitamin B-12 status on plasma homocysteine in women (20-30 y; n = 362). Plasma homocysteine was inversely (P < 0.0001) associated with serum folate and plasma vitamin B-12 regardless of genotype. ⋯ Predicted plasma homocysteine was inversely associated with serum folate (P = 0.003) and plasma vitamin B-12 (P = 0.002), with the degree of correlation dependent on MTHFR 677C-->T genotype. These data suggest that coexistence of the MTHFR 677 TT genotype with the MTRR 66A-->G polymorphism may exacerbate the effect of the MTHFR variant alone. The potential negative effect of combined polymorphisms of the MTHFR and MTRR genes on plasma homocysteine in at-risk population groups with low folate and/or vitamin B-12 status, such as women of reproductive potential, deserves further investigation.
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The Journal of nutrition · May 2004
Kupffer cell activity is involved in the hepatoprotective effect of dietary oligofructose in rats with endotoxic shock.
In the present study, we tested the hypothesis that dietary oligofructose (FOS) can modulate both the response to an endotoxic shock induced by lipopolysaccharide (LPS) administration and the activity of resident hepatic macrophages, i.e., Kupffer cells. Male Wistar rats (n = 5-9 per group) were fed a standard diet or a diet supplemented with 10 g/100 g FOS for 3 wk. LPS (10 mg/kg) or saline were injected i.p. after dietary treatment. ⋯ Precision-cut liver slices (PCLS) from FOS-treated rats released more TNF-alpha and PGE(2) into the incubation medium than PCLS from control rats, independently of LPS challenge in vitro. This would suggest that the higher Kupffer cell phagocytic activity and secretion capacity due to FOS supplementation improve LPS clearance in liver tissue and reduce hepatocyte alterations. This study supports the hypothesis that oligofructose might decrease liver tissue injury after endotoxic shock and sepsis.
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The Journal of nutrition · Apr 2004
Randomized Controlled Trial Comparative Study Clinical TrialVery low-carbohydrate and low-fat diets affect fasting lipids and postprandial lipemia differently in overweight men.
Hypoenergetic very low-carbohydrate and low-fat diets are both commonly used for short-term weight loss; however, few studies have directly compared their effect on blood lipids, with no studies to our knowledge comparing postprandial lipemia, an important independently identified cardiovascular risk factor. The primary purpose of this study was to compare the effects of a very low-carbohydrate and a low-fat diet on fasting blood lipids and postprandial lipemia in overweight men. In a balanced, randomized, crossover design, overweight men (n = 15; body fat >25%; BMI, 34 kg/m(2)) consumed 2 experimental diets for 2 consecutive 6-wk periods. ⋯ Postprandial lipemia was significantly reduced when the men consumed both diets compared with baseline, but the reduction was significantly greater after intake of the very low-carbohydrate diet. Mean and peak LDL particle size increased only after the very low-carbohydrate diet. The short-term hypoenergetic low-fat diet was more effective at lowering serum LDL-C, but the very low-carbohydrate diet was more effective at improving characteristics of the metabolic syndrome as shown by a decrease in fasting serum TAG, the TAG/HDL-C ratio, postprandial lipemia, serum glucose, an increase in LDL particle size, and also greater weight loss (P < 0.05).
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The Journal of nutrition · Apr 2004
Comparative StudyConsumption of foods rich in flavonoids is related to a decreased cardiovascular risk in apparently healthy French women.
A high consumption of flavonoids may lower cardiovascular risk through their antioxidant capacity. This study evaluated the relation between consumption of foods rich in flavonoids and estimated cardiovascular risk. A cross-sectional analysis was performed in 1286 women and 1005 men of the SU. ⋯ No relation between risk factors and flavonoid-rich food consumption was seen in men. Women in the highest tertile of flavonoid-rich food consumption were at lower risk for cardiovascular disease [odds ratio (OR): 0.31; 95%CI: 0.14, 0.68], whereas a positive tendency was seen in men (OR: 1.38; 95%CI: 0.96, 2.00). These results indicate that in women, a high consumption of flavonoid-rich foods may prevent cardiovascular disease.