The Journal of nutrition
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The Journal of nutrition · Feb 2001
Choose a diet that is low in saturated fat and cholesterol and moderate in total fat: subtle changes to a familiar message.
"Choose a diet that is low in saturated fat and cholesterol and moderate in total fat," issued in Nutrition and Your Health: Dietary Guidelines for Americans in the year 2000, has an interesting and lengthy history. The first guideline, for which there was extensive scientific data to show that dietary excess increased chronic disease risk, prompted much scientific discussion and debate when implemented as dietary guidance. Three major changes in the guideline are noted since it was issued in 1980, i.e., numerical goals for dietary fats; the applicability of recommended fat intakes for all individuals > or =2 y old; and rewording to emphasize reducing saturated fat and cholesterol intakes. ⋯ The lower intakes of saturated fat and cholesterol are consistent with decreases in blood cholesterol levels and lower rates of coronary mortality over the past 30 years. Strategies are needed and some are suggested, to further encourage the population to achieve a dietary pattern that is low in saturated fat and cholesterol and moderate in total fat. Other suggestions are offered to improve national nutrition monitoring and surveillance related to the guideline.
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We seek to discover an effective method for utilizing thermogenesis to reduce the caloric load in obese individuals. Experimental evidence indicates that nonshivering thermogenesis is the most effective cellular and biochemical mechanism known for reducing excessive adiposity. In this presentation, we describe our experiments aimed at understanding how nonshivering thermogenesis can be induced. In addition, these experiments have led to a genetic approach for the identification of variant genes that coordinate the expression of pathways of gene transcription that are associated with brown adipocyte induction.
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The Journal of nutrition · Nov 2000
Iron deficiency alters dopamine transporter functioning in rat striatum.
Iron deficiency anemia in early life produces profound changes in both in vivo and in vitro evaluations of dopamine (DA) functioning. This study employed both behavioral and biochemical approaches to examine the biological bases of alterations in striatal DA metabolism seen in iron-deficient rats. The purpose was to determine whether the DA transporter (DAT) was functionally altered in postweaning iron deficiency. ⋯ Radioligand binding assays with (3)H-1-(2-(diphenylmethoxy)-ethyl)-4-(3-phenylpropyl) piperazine ((3)H-GBR12935) demonstrated that iron deficiency did not alter the affinity of the ligand for the DAT but did significantly decrease the density of the transporter by 30% in caudate putamen and 20% in nucleus accumbens. Iron deficiency also significantly decreased (3)H-DA uptake into striatal synaptosomes, but did not affect release of DA with potassium chloride stimulation. These experiments provide supporting evidence that elevated levels of extracellular DA in the striatum of iron-deficient rats is likely to be the result of decreased DAT functioning and not increased rates of release.
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The Journal of nutrition · Jun 2000
Comparative StudyLDL of Taiwanese vegetarians are less oxidizable than those of omnivores.
The vegetarians in Taiwan consume diets high in polyunsaturated fatty acids. To investigate whether this dietary pattern results in high susceptibility of LDL to oxidation, 109 long-term (8 +/- 5 y) male and female vegans and lactovegetarians (ages 31-45 y) from Taipei and females from Hualien and matched omnivores were recruited to have 24-h-recall dietary assessments and blood lipid analysis. Body mass index and blood pressure were significantly lower in all vegetarian groups than in the matched omnivore groups (P < 0.05). ⋯ LDL-TBARS production was negatively related to LDL linoleic acid content (r = -0.36, P = 0.023), but positively related to LDL arachidonic (r = 0.56, P = 0.0002) and eicosapentaenoic (r = 0.45, P = 0.004) acids. No significant differences were found in dietary vitamins C and E intakes and plasma LDL alpha-tocopherol concentrations between vegetarians and omnivores. Our results suggest that vegetarian diets decrease the susceptibility of LDL to oxidation despite their higher dietary P/S ratio.