Longitudinal measurements of zinc absorption in Peruvian children consuming wheat products fortified with iron only or iron and 1 of 2 amounts of zinc

BACKGROUND: Information is needed on the fractional absorption of zinc (FAZ) and absorbed zinc (AZ) during prolonged exposure to zinc-fortified foods. OBJECTIVE: The objective was to measure FAZ and AZ from diets fortified with different amounts of zinc and to determine whether zinc absorption changes over approximately 7 wk. DESIGN: Forty-one stunted, moderately anemic children received daily, at breakfast and lunch, 100 g wheat products fortified with 3 mg Fe (ferrous sulfate) and 0 (group Zn-0), 3 (group Zn-3), or 9 (group Zn-9) mg Zn (zinc sulfate) per 100 g flour. FAZ was measured on days 2-3 and 51-52; meal-specific AZs were calculated as the product of FAZ and zinc intake. RESULTS: For the breakfast and lunch meals combined, mean total zinc intakes were 2.14, 4.72, and 10.04 mg/d in groups Zn-0, Zn-3, and Zn-9, respectively, during the initial absorption studies; mean (+/-SD) FAZ values were 0.341 +/- 0.111, 0.237 +/- 0.052, and 0.133 +/- 0.041, respectively, on days 2-3 (P < 0.001) and did not change significantly on days 51-52 in the subset of 31 children studied twice. Mean initial AZ was positively related to zinc intake (0.71 +/- 0.18, 1.11 +/- 0.21, and 1.34 +/- 0.47 mg/d, respectively; P < 0.001); final values did not differ significantly from the initial values. CONCLUSIONS: AZ from meals containing zinc-fortified wheat products increases in young children relative to the level of fortification and changes only slightly during approximately 7-wk periods of consumption. Although consumption of zinc-fortified foods may reduce FAZ, zinc fortification at the levels studied positively affects total daily zinc absorption, even after nearly 2 mo of exposure to zinc-fortified diets.     

Blood copper levels in Mexican users of the T380A IUD

OBJECTIVE: Copper T380A is one of the most commonly prescribed intrauterine devices (IUDs). However, there are few reports of its systemic health effects. This study evaluates the association between the use of T380A IUD and blood Cu levels in a group of Mexican users. METHODS: Eighty-six T380A users and eight nonusers were recruited. Blood Cu levels were measured using an atomic absorption spectrophotometic technique. RESULTS: In IUD users, mean blood Cu level was significantly higher than in nonusers, 216.63 vs. 107.47 microg/dL (p相似文献   

Molecular mechanisms of action and health benefits of polyunsaturated fatty acids

Essential polyunsaturated fatty acids (PUFAs), linoleic acid n6 (LA) and linolenic acid (ALA) n3 obtained from the diet are precursors of the long-chain polyunsaturated fatty acids (Lc-PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA) respectively. Consumption of PUFAs is related with a better neurological and cognitive development in newborns. It has been demonstrated that consumption of n-6 and n-3 PUFAs decreases blood triglycerides by increasing fatty acid oxidation through activation of PPARalpha or by reducing the activation of SREBP-1 inhibiting lipogenesis. Dietary PUFAs activate PPARalpha and PPARgamma increasing lipid oxidation, and decreasing insulin resistance leading in a reduction of hepatic steatosis. Beneficial effects of PUFAs have been observed in humans and in animals models of diabetes, obesity, cancer, and cardiovascular diseases. It is important to promote the consumption of PUFAs. Main food sources of PUFAs n-6 are corn, soy and safflower oil, and for PUFAs n-3 are fish, soy, canola oil and, flaxseed. Finally FAO/WHO recommends an optimal daily intake of n6/n3 of 5-10:1.     

Quercetin induces necrosis and apoptosis in SCC-9 oral cancer cells

Evidence has accumulated that dietary polyphenols, in particular, flavonoids, have protective effects against oral cancer. In this study, we have examined the effects of quercetin, a major dietary flavonoid, on cell growth and necrosis/apoptosis and cell cycle regulation in human oral squamous carcinoma SCC-9 cells. Quercetin induced dose- and time-dependent, irreversible inhibition of cell growth and cellular DNA synthesis. Light microscopy and lactate dehydrogenase measurements showed modifications in the morphology and membrane integrity of these cells after quercetin treatment. Propidium iodide/annexin V staining showed that quercetin induced necrosis at 24 h and 48 h, whereas at 72 h cells underwent apoptosis, correlating with caspase-3 activation. Flow cytometry studies of the cell cycle distribution showed that quercetin induced mainly S-phase arrest. Thymidylate synthase (TS), a key S-phase enzyme, was inhibited in a time- and dose-dependent fashion by quercetin at the protein level. A lack of effect on TS mRNA suggested that TS down-regulation occurred at the translational level. In conclusion, our data support a view that quercetin initially induces a stress response, resulting in necrosis of these oral epithelial cells. Prolonged exposure of the surviving cells to quercetin causes apoptosis, presumably mediated by inhibition of TS protein.