Human skin condition and its associations with nutrient concentrations in serum and diet.
(73/785)
BACKGROUND: Nutritional factors exert promising actions on the skin, but only scant information is available on the modulating effects of physiologic concentrations of nutrients on the skin condition of humans. OBJECTIVE: The objective was to evaluate whether nutrient concentrations in serum and diet are associated with the skin condition of humans. DESIGN: A cross-sectional study was conducted in which data on serum concentrations of nutrients, dietary intake of nutrients, and the hydration, sebum content, and surface pH of skin were obtained from 302 healthy men and women. Skin condition was measured with the use of noninvasive techniques. Dietary intake was assessed with 2 complementary food-frequency questionnaires. Multiple regression analysis was used to evaluate associations of serum vitamins and carotenoids and of dietary micro- and macronutrients with skin condition. RESULTS: After adjustment for potential confounders, including sex, age, and smoking, statistically significant associations were shown in the total population between serum vitamin A and skin sebum content and surface pH and between the dietary intake of total fat, saturated fat, monounsaturated fat, and skin hydration. Monounsaturated fat intake was also associated with surface pH. Associations between serum beta-cryptoxanthin and skin hydration and between surface pH and fluid and calcium intakes were observed in men only. CONCLUSION: Several associations between nutrients in serum and diet and skin condition were observed, indicating that changes in baseline nutritional status may affect skin condition. (+info)
Prospective study of antioxidant micronutrients in the blood and the risk of developing prostate cancer.
(74/785)
Antioxidant micronutrients may have chemopreventive effects. The authors examined the associations between prediagnostic blood levels of micronutrients and prostate cancer risk in two nested case-control studies of 9,804 and 10,456 male residents of Washington County, Maryland, who donated blood in 1974 (CLUE I) and 1989 (CLUE II), respectively. Until 1996, 182 men for whom adequate serum remained for assays in the CLUE I cohort and 142 men in the CLUE II cohort developed prostate cancer. Each case was matched with two controls by age, gender, race, and date of blood donation. In both cohorts, cases and controls had similar concentrations of alpha-carotene, beta-carotene, total carotene, beta-cryptoxanthin, lutein, lycopene, retinol, and ascorbic acid; serum alpha-tocopherol was weakly associated with prostate cancer risk. Higher retinyl palmitate concentrations were associated with a lower risk in CLUE I but not CLUE II. In CLUE I, cases had lower concentrations of gamma-tocopherol than did controls (p = 0.02), but no dose-response trend was observed. A strong inverse association between gamma-tocopherol and prostate cancer risk was observed in CLUE II. Findings do not replicate previous reports of a protective association between lycopene and prostate cancer, but they suggest potential chemopreventive effects of gamma-tocopherol on prostate cancer. (+info)
Antioxidant micronutrients and risk of rheumatoid arthritis in a cohort of older women.
(75/785)
The association of antioxidant vitamins and trace elements from foods and supplements with risk of rheumatoid arthritis was evaluated in a prospective cohort study of 29,368 women who were aged 55-69 years at baseline in 1986. Through 1997, 152 cases of rheumatoid arthritis were identified. After controlling for other risk factors, greater intakes (highest tertile vs. lowest) of supplemental vitamin C (relative risk (RR) = 0.70, 95% confidence interval (CI): 0.48, 1.09; p-trend = 0.08) and supplemental vitamin E (RR = 0.72, 95% CI: 0.47, 1.12; p-trend = 0.06) were inversely associated with rheumatoid arthritis. There was no association with total carotenoids, alpha- or beta-carotene, lycopene, or lutein/zeaxanthin, while there was an inverse association with beta-cryptoxanthin (RR = 0.59, 95% CI: 0.39, 0.90; p-trend = 0.01). Greater use of supplemental zinc (RR = 0.39, 95% CI: 0.17, 0.88; p-trend = 0.03) was inversely associated with rheumatoid arthritis, while any use of supplemental copper (RR = 0.54, 95% CI: 0.28, 1.03) and manganese (RR = 0.50, 95% CI: 0.23, 1.07) showed suggestive inverse associations with rheumatoid arthritis. Greater intakes of fruit (RR = 0.72, 95% CI: 0.46, 1.12; p-trend = 0.13) and cruciferous vegetables (RR = 0.65, 95% CI: 0.42, 1.01; p-trend = 0.07) also exhibited trends toward inverse associations with risk. When the antioxidants were modeled together, only beta-cryptoxanthin and supplemental zinc were statistically significant predictors. Intake of certain antioxidant micronutrients, particularly beta-cryptoxanthin and supplemental zinc, and possibly diets high in fruits and cruciferous vegetables, may be protective against the development of rheumatoid arthritis. (+info)
Multiple micronutrient supplementation during pregnancy does not lead to greater infant birth size than does iron-only supplementation: a randomized controlled trial in a semirural community in Mexico.
(76/785)
BACKGROUND: Little is known about the benefits of prenatal multivitamin and mineral supplements in reducing low birth weight. OBJECTIVE: We conducted a randomized, double-blind clinical trial in semirural Mexico to compare the effects of multiple micronutrient (MM) supplements with those of iron supplements during pregnancy on birth size. DESIGN: Pregnant women (n = 873) were recruited before 13 wk of gestation and received supplements 6 d/wk at home, as well as routine antenatal care, until delivery. Both supplements contained 60 mg Fe, but the MM group also received 1-1.5 times the recommended dietary allowances of several micronutrients. RESULTS: At recruitment, the women in the 2 groups were not significantly different in age, parity, economic status, height, or hemoglobin concentration but differed significantly in marital status (4.6% and 2.0% of women in the MM and iron-only groups, respectively, were single mothers) and mean (+/- SD) body mass index (in kg/m(2); 24.6 +/- 4.3 and 23.8 +/- 3.9 in the iron-only and MM groups, respectively). Losses to follow-up (25%) and compliance (95%) did not differ significantly between the groups. In intent-to-treat analyses (MM group: n = 323; iron-only group: n = 322), mean (+/- SD) birth weight (2.981 +/- 0.391 and 2.977 +/- 0.393 kg in the MM and iron-only groups, respectively) and birth length (48.61 +/- 1.82 and 48.66 +/- 1.83 cm in the MM and iron-only groups, respectively) did not differ significantly between the groups. CONCLUSION: These findings suggest that MM supplementation during pregnancy does not lead to greater infant birth size than does iron-only supplementation. (+info)
Effects of alternative maternal micronutrient supplements on low birth weight in rural Nepal: double blind randomised community trial.
(77/785)
OBJECTIVE: To assess the impact on birth size and risk of low birth weight of alternative combinations of micronutrients given to pregnant women. DESIGN: Double blind cluster randomised controlled trial. SETTING: Rural community in south eastern Nepal. PARTICIPANTS: 4926 pregnant women and 4130 live born infants. INTERVENTIONS: 426 communities were randomised to five regimens in which pregnant women received daily supplements of folic acid, folic acid-iron, folic acid-iron-zinc, or multiple micronutrients all given with vitamin A, or vitamin A alone (control). MAIN OUTCOME MEASURES: Birth weight, length, and head and chest circumference assessed within 72 hours of birth. Low birth weight was defined <2500 g. RESULTS: Supplementation with maternal folic acid alone had no effect on birth size. Folic acid-iron increased mean birth weight by 37 g (95% confidence interval -16 g to 90 g) and reduced the percentage of low birthweight babies (<2500 g) from 43% to 34% (16%; relative risk=0.84, 0.72 to 0.99). Folic acid-iron-zinc had no effect on birth size compared with controls. Multiple micronutrient supplementation increased birth weight by 64 g (12 g to 115 g) and reduced the percentage of low birthweight babies by 14% (0.86, 0.74 to 0.99). None of the supplement combinations reduced the incidence of preterm births. Folic acid-iron and multiple micronutrients increased head and chest circumference of babies, but not length. CONCLUSIONS: Antenatal folic acid-iron supplements modestly reduce the risk of low birth weight. Multiple micronutrients confer no additional benefit over folic acid-iron in reducing this risk. (+info)
Randomized efficacy trial of a micronutrient-fortified beverage in primary school children in Tanzania.
(78/785)
BACKGROUND: Dietary supplements providing physiologic amounts of several micronutrients simultaneously have not been thoroughly tested for combating micronutrient deficiencies. OBJECTIVE: We determined whether a beverage fortified with 10 micronutrients at physiologic doses influenced the iron and vitamin A status and growth of rural children (aged 6-11 y) attending primary schools. DESIGN: In this randomized, double-blind, placebo-controlled efficacy trial, children were assigned to receive the fortified beverage or an unfortified beverage at school for 6 mo. RESULTS: There were nonsignificant differences at baseline between children in the fortified and nonfortified groups in iron status, serum retinol, and anthropometry. At the 6-mo follow-up, among children with anemia (hemoglobin < 110 g/L), there was a significantly larger increase in hemoglobin concentration in the fortified group than in the nonfortified group (9.2 and 0.2 g/L, respectively). Of those who were anemic at baseline, 69.4% in the nonfortified group and 55.1% in the fortified group remained anemic at follow-up (RR: 0.79), a cure rate of 21%. The prevalence of children with low serum retinol concentrations (< 200 microg/L) dropped significantly from 21.4% to 11.3% in the fortified group compared with a nonsignificant change (20.6% to 19.7%) in the nonfortified group. At follow-up, mean incremental changes in weight (1.79 compared with 1.24 kg), height (3.2 compared with 2.6 cm), and BMI (0.88 compared with 0.53) were significantly higher in the fortified group than in the nonfortified group. CONCLUSION: The fortified beverage significantly improved hematologic and anthropometric measurements and significantly lowered the overall prevalence of anemia and vitamin A deficiency. (+info)
The metabolic tune-up: metabolic harmony and disease prevention.
(79/785)
An optimum intake of micronutrients and metabolites, which varies with age and genetic constitution, would tune up metabolism and give a marked increase in health, particularly for the poor and elderly, at little cost. 1) DNA damage. Inadequate intake of folic acid causes millions of uracils to be incorporated into the DNA of each cell with associated chromosome breaks, essentially producing a radiation mimic. Deficiencies of the metabolically connected vitamins B-6 and B-12, which are also widespread, also cause uracil incorporation and chromosome breaks. Inadequate iron intake (2 billion women in the world; 25% of U.S. menstruating women) causes oxidants to leak from mitochondria and damages mitochondria and mitochondrial DNA. Inadequate zinc intake (approximately 10% in the U.S.) causes oxidation and DNA damage in human cells. 2) The K(m) concept. Approximately 50 different human genetic diseases that are due to a poorer binding affinity (K(m)) of the mutant enzyme for its coenzyme can be remedied by feeding high-dose B vitamins, which raise levels of the corresponding coenzyme. Many polymorphisms also result in a lowered affinity of enzyme for coenzyme. 3) Mitochondrial oxidative decay with age. This decay, which is a major contributor to aging, can be ameliorated by feeding old rats the normal mitochondrial metabolites acetyl carnitine and lipoic acid at high levels. They restore the K(m) for acetyl carnitine transferase and the velocity of the reaction as well as mitochondrial function; reduce levels of oxidants, neuron RNA oxidation and mutagenic aldehydes; and increase old-rat ambulatory activity and cognition. (+info)
The plausibility of micronutrient deficiencies being a significant contributing factor to the occurrence of pregnancy complications.
(80/785)
Numerous studies support the concept that a major cause of pregnancy complications can be suboptimal embryonic and fetal nutrition. Although the negative effects of diets low in energy on pregnancy outcome are well documented, less clear are the effects of diets that are low in one or more essential micronutrients. However, several observational and intervention studies suggest that diets low in essential vitamins and minerals can pose a significant reproductive risk in diverse human populations. Although maternal nutritional deficiencies typically occur as a result of low dietary intakes of essential nutrients, nutritional deficiencies at the level of the conceptus can arise through multiple mechanisms. Evidence from experimental animals supports the concept that in addition to primary deficiencies, secondary embryonic and fetal nutritional deficiencies can be caused by diverse factors including genetics, maternal disease, toxicant insults and physiological stressors that can trigger a maternal acute phase response. These secondary responses may be significant contributors to the occurrence of birth defects. An implication of the above is that the frequency and severity of pregnancy complications may be reduced through an improvement in the micronutrient status of the mother. (+info)