RESUMO
Background: Many types of people have been noted to show less than maximum zinc functional status. One group that has not been examined is healthy middle-aged, non-vegetarian men in the USA. Aim: To determine if supplementation with zinc improves values for two plasma indicators of zinc status. Methods: Zinc arginate (30â mg zinc/day) was given for 6 weeks to healthy middle-aged men. Results: Supplementation produced statistically significant, but small increases in plasma values for zinc and activity of 5'-nucleotidase, a zinc enzyme. Conclusion: These results suggest that middle-aged, healthy, meat-eating US males tend to show close to maximal zinc functional status. However, such men may not have a safety margin in zinc stores that covers situations where higher than normal zinc needs develop.
Assuntos
5'-Nucleotidase , Zinco , Humanos , Masculino , Pessoa de Meia-Idade , Suplementos Nutricionais , Nível de Saúde , Estado Nutricional , Estados UnidosRESUMO
Spirulina may increase people's ability to resist mental and physical fatigue. This study tested that hypothesis in a randomized, double blinded, placebo controlled study in men. After 1 week, a 3 g/day dose of spirulina produced a small, but statistically significant increase in exercise output (Kcals consumed in 30 min exercise on a cross trainer machine). A mathematical based mental fatigue test showed improved performance 4 h after the first time of supplementation as well as 8 weeks later. Similarly, a subjective survey for a sense of physical and mental fatigue showed improvement within 4 h of the first supplementation as well as 8 weeks later. These results show that spirulina intake can affect fatigue in men.
Assuntos
Suplementos Nutricionais , Fadiga/tratamento farmacológico , Fadiga Mental/tratamento farmacológico , Spirulina , Adulto , Método Duplo-Cego , Exercício Físico , Humanos , MasculinoRESUMO
BACKGROUND: The percent absorption of lutein from supplements falls well below that from lutein enriched egg yolk, a rich source of phospholipids. Therefore, a supplement of lutein plus phospholipids was tested for effects on serum accumulation. METHODS: A 10 day supplementation with a solid-lipid particle (SLP) lutein complex or conventional lutein ester was done in apparently healthy people (both supplement types taken with fat containing meals). Plasma lutein was measured pre- and post-supplementation as well as 7 days after supplementation stopped. Changes within each supplement group were analyzed by paired t-test; group comparisons were done by unpaired t-test. RESULTS: The solid-lipid particle complex lutein gave much higher plasma lutein values than conventional lutein ester. The lutein complex showed superior effects based on absolute mean value after 10 days of supplementation, change in value from baseline to 10 days, and value at 7 days after supplement discontinuation. CONCLUSIONS: A solid lipid lutein complex strongly increased plasma lutein levels compared to a conventional form.
Assuntos
Suplementos Nutricionais/estatística & dados numéricos , Luteína/administração & dosagem , Luteína/sangue , Fosfolipídeos/administração & dosagem , Fosfolipídeos/sangue , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Curcumin extracts of turmeric are proposed to produce health benefits. To date, human intervention studies have focused mainly on people with existing health problems given high doses of poorly absorbed curcumin. The purpose of the current study was to check whether in healthy people, a low dose of a lipidated curcumin extract could alter wellness-related measures. METHODS: The present study was conducted in healthy middle aged people (40-60 years old) with a low dose of curcumin (80 mg/day) in a lipidated form expected to have good absorption. Subjects were given either curcumin (N = 19) or placebo (N = 19) for 4 wk. Blood and saliva samples were taken before and after the 4 weeks and analyzed for a variety of blood and saliva measures relevant to health promotion. RESULTS: Curcumin, but not placebo, produced the following statistically significant changes: lowering of plasma triglyceride values, lowering of salivary amylase levels, raising of salivary radical scavenging capacities, raising of plasma catalase activities, lowering of plasma beta amyloid protein concentrations, lowering of plasma sICAM readings, increased plasma myeloperoxidase without increased c-reactive protein levels, increased plasma nitric oxide, and decreased plasma alanine amino transferase activities. CONCLUSION: Collectively, these results demonstrate that a low dose of a curcumin-lipid preparation can produce a variety of potentially health promoting effects in healthy middle aged people.
Assuntos
Envelhecimento , Anti-Inflamatórios não Esteroides/uso terapêutico , Antioxidantes/uso terapêutico , Curcuma/química , Curcumina/administração & dosagem , Suplementos Nutricionais , Extratos Vegetais/uso terapêutico , Adulto , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/prevenção & controle , Anti-Inflamatórios não Esteroides/química , Antioxidantes/química , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/metabolismo , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Curcumina/química , Feminino , Humanos , Hipertrigliceridemia/epidemiologia , Hipertrigliceridemia/prevenção & controle , Lipídeos/administração & dosagem , Lipídeos/química , Masculino , Pessoa de Meia-Idade , Ohio/epidemiologia , Extratos Vegetais/química , Raízes de Plantas/química , Risco , Estresse Psicológico/epidemiologia , Estresse Psicológico/prevenção & controleRESUMO
Frequent heartburn occurs in many people, some of whom prefer alternative treatments over conventional drugs. In a pilot study of subjects with frequent heartburn, 2 week intake of a fenugreek fiber product, taken 30 min before two meals/day, diminished heartburn severity. This conclusion was based on symptom diary results and reduced the use of a mild antacid as a rescue medicine. Improvement for each of the 2 weeks was judged by comparison with results from a baseline week. Placebo also produced some statistically significant effects, but the fiber product's effects differed significantly from the placebo. Moreover, the fenugreek fiber effects were generally similar to the results produced by an OTC antacid medication (ranitidine at 75 mg, twice a day). This study suggests that people with certain degrees of heartburn can benefit from a fenugreek fiber product.
Assuntos
Fibras na Dieta/uso terapêutico , Azia/tratamento farmacológico , Trigonella/química , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos PilotoRESUMO
Activity of the immunoregulatory peptide thymulin reflects differences in zinc status. This study compared thymulin activity with four other zinc status measures in rats fed zinc at either 5 or 25 ppm. Rats fed the lower zinc showed the following results compared with rats with adequate zinc intake: serum thymulin activity 61% lower, serum zinc 31% lower, serum extracellular superoxide dismutase 18% lower, serum 5'-nucleotidase activity 26% lower, and liver metallothionein 28% lower. Thus, thymulin activities showed more sensitivity to restricted zinc intake than did four other parameters.
Assuntos
Fator Tímico Circulante , Zinco , Animais , Fígado , Metalotioneína , RatosRESUMO
Some research has raised the possibility that gamma linolenic acid (GLA) can increase resting metabolic rate (RMR), which can help with weight control. However, in overweight young adults with a family history of obesity, no effect on RMR was seen after a 6 weeks treatment with borage oil (880 mg GLA per day) or evening primrose oil (540 mg GLA per day). On the other hand, borage oil did lower plasma triglyceride readings and raise HDL cholesterol readings (mean starting values in normal range for triglycerides, borderline low for HDL). No effect was seen for body mass index, plasma total cholesterol, LDL cholesterol, or glucose. Thus, in the type of subjects studied here, borage oil, a source of GLA, did not show promise as a weight control aid, but could help prevent undesirable readings for two blood lipid measures.
Assuntos
Obesidade/prevenção & controle , Óleos de Plantas/administração & dosagem , Ácido gama-Linolênico/administração & dosagem , Administração Oral , Adulto , HDL-Colesterol/metabolismo , Feminino , Alimento Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Fitoterapia , Óleos de Plantas/farmacologia , Resultado do Tratamento , Triglicerídeos/metabolismo , Adulto Jovem , Ácido gama-Linolênico/farmacologiaRESUMO
BACKGROUND: Elite female athletes have shown vulnerability to various degrees of iron deficiency. Less is known about recreational fitness exercisers. A study was done to examine plasma ferritin, an assessor of iron status, in young adult, university student fitness runners. METHODS: The present study examined serum ferritin concentrations, an indicator of iron status, in 39 female university students (age 18-25) who ran for fitness, but ran less than competition runners. Selected subjects all reported themselves as not anemic. RESULTS: Mean + SD for 3 mile run time was 26.25 + 3.0 min. The mean ferritin reading was low: 12.4 + 12.3 ng/mL (+ SD). Out of the 39 women, 29 had readings that fell below 15 ng/mL, which some consider the cutoff for iron deficiency. In addition, all but 2 subjects had values below 35, which has been proposed as Stage 1 iron deficiency for athletes. Ferritin levels did not correlate with 3 mile run times (Pearson correlation coefficient, P > 0.05). A 1 mo intervention with 3 minerals that included iron (36 mg/day) significantly raised ferritin values when the iron was bisglycinate (p < 0.05), but not when it was ferrous sulfate (p > 0.05). CONCLUSION: In this study, a degree of iron deficiency was seen in most of a group of female fitness runners (each of whom had self reported as not being anemic).
Assuntos
Ferritinas/sangue , Adolescente , Adulto , Anemia Ferropriva/sangue , Feminino , Humanos , Ferro/sangue , Corrida , Universidades , Adulto JovemRESUMO
OBJECTIVE: Zinc deficiency is common among populations at high risk for sepsis mortality, including elderly, alcoholic, and hospitalized patients. Zinc deficiency causes exaggerated inflammatory responses to endotoxin but has not been evaluated during bacterial sepsis. We hypothesized that subacute zinc deficiency would amplify immune responses and oxidant stress during bacterial sepsis {lsqb;i.e., cecal ligation and puncture (CLP){rsqb; resulting in increased mortality and that acute nutritional repletion of zinc would be beneficial. DESIGN: Prospective, randomized, controlled animal study. SETTING: University medical center research laboratory. SUBJECTS: Adult male C57BL/6 mice. INTERVENTIONS: Ten-week-old, male, C57BL/6 mice were randomized into three dietary groups: 1) control diet, 2) zinc-deficient diet for 3 weeks, and 3) zinc-deficient diet for 3 weeks followed by oral zinc supplementation for 3 days (n = 35 per diet). Mice were then assigned to receive either CLP or sham operation (n = 15 each per diet). CLP and sham-operated treatment groups were further assigned to a 7-day survival study (n = 10 per treatment per diet) or were evaluated at 24 hours (n = 5 per treatment per diet) for signs of vital organ damage. MEASUREMENTS AND MAIN RESULTS: Sepsis mortality was significantly increased with zinc deficiency (90% vs. 30% on control diet). Zinc-deficient animals subject to CLP had higher plasma cytokines, more severe organ injury, including increased oxidative tissue damage and cell death, particularly in the lungs and spleen. None of the sham-operated animals died or developed signs of organ damage. Zinc supplementation normalized the inflammatory response, greatly diminished tissue damage, and significantly reduced mortality. CONCLUSIONS: Subacute zinc deficiency significantly increases systemic inflammation, organ damage, and mortality in a murine polymicrobial sepsis model. Short-term zinc repletion provides significant, but incomplete protection despite normalization of inflammatory and organ damage indices.
Assuntos
Insuficiência de Múltiplos Órgãos/etiologia , Insuficiência de Múltiplos Órgãos/mortalidade , Sepse/complicações , Sepse/mortalidade , Zinco/deficiência , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sepse/microbiologiaRESUMO
Pomegranate components have properties that could promote oral health, including reducing the risk of gingivitis. The present study examined young adults (n = 32, split evenly among both genders), for the effects of 4 weeks of thrice daily mouth rinsing with the pomegranate (Punica granatum L.) extract PomElla dissolved in water. This treatment changed salivary measures relevant to oral health including gingivitis. The changes were: reduced total protein (which can correlate with plaque forming bacteria readings), reduced activities of aspartate aminotransferase (an indicator of cell injury), reduced alpha-glucosidase activity (a sucrose degrading enzyme), increased activities of the antioxidant enzyme ceruloplasmin (which could give better protection against oral oxidant stress) and increased radical scavenging capacity (though this increase was significant only by nonparametric statistical analysis). A placebo of cornstarch in water did not affect these measures. These data raise the possibility of using pomegranate extracts in oral health products such as toothpaste and mouthwashes.
Assuntos
Gengivite/prevenção & controle , Lythraceae/química , Antissépticos Bucais/uso terapêutico , Saliva/química , Adulto , Feminino , Humanos , Masculino , Saliva/enzimologia , Adulto JovemRESUMO
BACKGROUND: The current pilot study tested a twofold hypothesis: some nutrition-related chemical measures change by 6 weeks after Roux en Y Gastric Bypass (RNYGB); one of two nutrition support plans will prevent chemical signs of nutrition problems at 6 weeks better than the other. After RNYGB, nutrition support should begin right away. However, studies on nutritional status mostly examine subjects much later. In addition, little attention has been paid to optimizing nutrition support plans. METHODS: Premenopausal females scheduled for RNYGB were given either a commercially available meal replacement product (2 servings/day) + other supplements or just a new meal replacement (2 servings/day). The latter included some nutrient versions that might enhance absorption. Blood and urine samples were taken before and 6 weeks after surgery. RESULTS: In both groups, plasma vitamin D and B12 did not change, plasma osteopontin and vascular endothelial growth factor rose, while plasma retinol binding protein and a bone resorption marker declined. Copper status changes differed between groups based on plasma ceruloplasmin. Iron status improved in both groups (ferritin to c-reactive protein ratios). With the new formulation, magnesium status may have improved, urinary potassium rose, and blood sugar fell. In the other group, a liver damage marker increased, while homocysteine decreased. CONCLUSIONS: Nutrition-related parameters showed varying trends 6 weeks after RNYGB. Some of the trends were affected by the type of nutritional support provided.
Assuntos
Derivação Gástrica , Estado Nutricional/fisiologia , Apoio Nutricional , Adulto , Glicemia/análise , Feminino , Humanos , Apoio Nutricional/métodos , Apoio Nutricional/estatística & dados numéricos , Projetos Piloto , Vitaminas/sangueRESUMO
Kava, like a number of herbals, has been associated with causing liver damage based on limited evidence. In contrast, the present study found that in rats, 3 mo feedings of two types of kava extracts (an acetone extract and an ethanol extract of the Samoan kava cultivar Ava Laau) at three different doses (31.25, 62.5 and 133 mg/kg diet) produced no liver injury based on serum markers of liver damage (sorbitol dehydrogenase activities, bile acid concentrations, and beta-glucuronidase activities) and serum lipid peroxide readings. In fact, for some measurements and some kava doses, the injury marker readings were below control values. Moreover, for these same parameters, kava feeding did not enhance the effects of the hepatotoxin galacatosamine (500 mg/kg ip); some kava doses even showed modest protection against liver injury. Liver histology analysis showed no signs of kava causing or enhancing liver injury. Thus, this study does not support the concept that kava produces or aggravates liver injury.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Galactosamina/toxicidade , Kava/química , Fígado/efeitos dos fármacos , Extratos Vegetais/toxicidade , Acetona/química , Animais , Ácidos e Sais Biliares/sangue , Biomarcadores/metabolismo , Dieta , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Etanol/química , Glucuronidase/sangue , L-Iditol 2-Desidrogenase/sangue , Peróxidos Lipídicos/sangue , Fígado/enzimologia , Fígado/patologia , Testes de Função Hepática , Masculino , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Solventes/químicaRESUMO
Chromium (Cr) supplements are available as picolinate, nicotinate or chloride (the latter primarily in multivitamin-mineral supplements). The picolinate form has been reported to be the best absorbed and most efficacious, but some reports question which form has superior absorption. The present study examined acute Cr absorption, based on 24h urinary Cr values, for picolinate, two types of nicotinate, and chloride in young adult, non-overweight females. College-aged women were given 200 microg of Cr as each of the four supplement types in random order accompanied by a small standardized meal, separated by at least a week washout. Cr picolinate produced significantly higher 24h urinary Cr than either of two nicotinate supplements or Cr chloride given in a multivitamin-mineral supplement. This difference was seen for absolute values of the urinary Cr and for percent increases. In conclusion, based on an indirect measure of acute absorption, Cr picolinate was superior to three other Cr complexes commonly sold as supplements.
Assuntos
Compostos de Cromo , Suplementos Nutricionais , Absorção Intestinal/fisiologia , Adulto , Compostos de Cromo/administração & dosagem , Compostos de Cromo/química , Compostos de Cromo/metabolismo , Feminino , HumanosRESUMO
BACKGROUND: Certain essential and conditionally essential nutrients (CENs) perform functions involved in aerobic exercise performance. However, increased intake of such nutrient combinations has not actually been shown to improve such performance. METHODS: For 1 mo, aerobically fit, young adult women took either a combination of 3 mineral glycinate complexes (daily dose: 36 mg iron, 15 mg zinc, and 2 mg copper) + 2 CENs (daily dose: 2 g carnitine and 400 mg phosphatidylserine), or the same combination with generic mineral complexes, or placebo (n = 14/group). In Trial 1, before and after 1 mo, subjects were tested for 3 mile run time (primary outcome), followed by distance covered in 25 min on a stationary bike (secondary outcome), followed by a 90 s step test (secondary outcome). To test reproducibility of the run results, and to examine a lower dose of carnitine, a second trial was done. New subjects took either mineral glycinates + CENs (1 g carnitine) or placebo (n = 17/group); subjects were tested for pre- and post-treatment 3 mile run time (primary outcome). RESULTS: In Trial 1, the mineral glycinates + CENs decreased 3 mile run time (25.6 ± 2.4 vs 26.5 ± 2.3 min, p < 0.05, paired t-test) increased stationary bike distance after 25 min (6.5 ± 0.6 vs 6.0 ± 0.8 miles, p < 0.05, paired t-test), and increased steps in the step test (43.8 ± 4.8 vs 40.3 ± 6.4 steps, p < 0.05, paired t-test). The placebo significantly affected only the biking distance, but it was less than for the glycinates-CENs treatment (0.2 ± 0.4. vs 0.5 ± 0.1 miles, p < 0.05, ANOVA + Tukey). The generic minerals + CENs only significantly affected the step test (44.1 ± 5.2 vs 41.0 ± 5.9 steps, p < 0.05, paired t-test) In Trial 2, 3 mile run time was decreased for the mineral glycinates + CENs (23.9 ± 3.1 vs 24.7 ± 2.5, p < 0.005, paired t-test), but not by the placebo. All changes for Test Formula II or III were high compared to placebo (1.9 to 4.9, Cohen's D), and high for Test Formula II vs I for running and biking (3.2 & 3.5, Cohen's D). CONCLUSION: In summary, a combination of certain mineral complexes plus two CENs improved aerobic exercise performance in fit young adult women.
Assuntos
Antioxidantes/administração & dosagem , Carnitina/administração & dosagem , Quelantes/administração & dosagem , Suplementos Nutricionais , Exercício Físico/fisiologia , Fosfatidilserinas/administração & dosagem , Resistência Física/efeitos dos fármacos , Resistência Física/fisiologia , Adulto , Cobre , Feminino , Voluntários Saudáveis , Humanos , Ferro , Consumo de Oxigênio/efeitos dos fármacos , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Reprodutibilidade dos Testes , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto Jovem , ZincoRESUMO
Antioxidant/anti-inflammatory effects of isoflavone-containing soy protein could partly explain why hemodialysis patients in Japan tend to outlive U.S. hemodialysis patients. However, a safety concern is that dialysis patients do not clear isoflavones well. A low-dose intervention with high isoflavone soy protein (25 g protein, four times a week for 4 weeks) was tested in 17 U.S. hemodialysis patients (eight given soy protein, nine given whey protein as a control). Soy protein intake produced no harmful effects based on a typical battery of blood safety tests. Post-treatment isoflavone levels, though high, were similar to those reported after a single 20-g soy protein intake by dialysis patients. In addition, intake of soy, but not whey, reduced plasma values for oxidized low-density lipoprotein, a risk factor for cardiovascular disease, which is a common mortality cause in hemodialysis patients. Three other measures of oxidant stress and/or inflammation were unchanged by the modest high isoflavone soy protein intervention. In conclusion, in hemodialysis patients, a fairly short, low intake level intervention with high isoflavone soy protein produced no obvious harm, and produced one potentially beneficial effect. This justifies tests of higher-dose, longer interventions with soy protein in hemodialysis patients.
Assuntos
Antioxidantes/administração & dosagem , Diálise Renal , Proteínas de Soja/administração & dosagem , Proteínas de Soja/efeitos adversos , Adulto , Idoso , Feminino , Genisteína/sangue , Humanos , Isoflavonas/análise , Isoflavonas/sangue , Isoflavonas/farmacocinética , Cinética , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Proteínas do Leite , Fitoterapia , Proteínas de Soja/química , Proteínas do Soro do LeiteRESUMO
We evaluated whether a daily high-dose calcium supplement perturbs the zinc status in 23 postmenopausal women (mean age: 63 yr) with low bone mineral density. Plasma and erythrocyte zinc concentrations, plasma bone-specific alkaline phosphatase (BSAP) and 5'-nucleotidase activities, and urinary zinc and calcium excretion were determined first at the end of 4 wk of daily oral calcium (1200 mg) and were measured again at the end of the subsequent 4 wk of daily cosupplementation with calcium (1200 mg) and zinc (30 mg). Mean plasma and erythrocyte zinc concentrations after 4 wk of calcium alone were not significantly different from concentrations after cosupplementation of calcium and zinc. Mean plasma BSAP activities before cosupplementation with zinc was significantly higher than that after zinc (p < 0.02), whereas plasma 5'-nucleotidase activities were not affected by zinc supplementation. Urinary zinc excretion slightly, but significantly, increased after the supplementation of zinc (p < 0.05), whereas calcium excretion remained similar. Our data indicate that a 4-wk zinc supplementation did not significantly improve zinc status. Although limited by the small sample size and short study duration, our data suggest that a daily calcium dose of 1200 mg had no effect on the zinc status of our subjects.
Assuntos
Densidade Óssea , Cálcio/administração & dosagem , Suplementos Nutricionais , Zinco/análise , 5'-Nucleotidase/sangue , Idoso , Fosfatase Alcalina/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa , Espectrofotometria Atômica , Zinco/sangue , Zinco/urinaRESUMO
OBJECTIVE: The aim of this study was to review the published evidence for a role of zinc nutrition in attention-deficit/hyperactivity disorder (ADHD). METHOD: A computer literature search was supplemented by the authors' knowledge. RESULTS: Numerous controlled studies report cross-sectional evidence of lower zinc tissue levels (serum, red cells, hair, urine, nails) in children who have ADHD, compared to normal controls and population norms. A few studies show correlations of zinc level with either clinical severity or a change thereof in response to stimulant or chemical challenge. Two placebo-controlled trials--one of zinc monotherapy, the other of zinc supplementation of methylphenidate--reported significant benefit. However, diagnostic procedures and sample representativeness were often not clear, and most such reports have come from countries and cultures with different diets and/or socioeconomic realities than are found in the United States (only one American sample in nine published reports). In particular, both positive clinical trials of zinc supplementation came from the Mid-East (Turkey and Iran), an area with suspected endemic zinc deficiency. The largest of these trials used zinc doses above the recommended upper tolerable limit and had a 2 in 3 dropout rate. CONCLUSION: It is not clear how well the accumulating evidence for a possible role of zinc in ADHD applies to middle-class American children. However, the evidence appears strong enough to warrant further controlled study in well-diagnosed samples representative of the socioeconomic spectrum. Hypothesis-testing clinical trials are needed of this potential treatment that, if found effective, might become a relatively safe, cheap substitute for, or adjunct to, current treatments in some patients. At present, it should remain an investigational treatment.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Zinco/fisiologia , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Encéfalo/fisiologia , Criança , Ensaios Clínicos como Assunto , Humanos , Zinco/deficiência , Zinco/metabolismo , Zinco/uso terapêuticoRESUMO
OBJECTIVE: The aim of this study was to explore the relationship of zinc nutrition to the severity of attention-deficit/hyperactivity disorder (ADHD) symptoms in a middle-class American sample with well-diagnosed ADHD. Previous reports of zinc in ADHD, including two positive clinical trials of supplementation, have come mainly from countries and cultures with different diets and/or socioeconomic realities. METHOD: Children 5-10 years of age with DISC- and clinician-diagnosed ADHD had serum zinc determinations and parent and teacher ratings of ADHD symptoms. Zinc levels were correlated (Pearson's and multiple regression) with ADHD symptom ratings. RESULTS: Forty-eight children (37 boys, 11 girls; 33 combined type, 15 inattentive) had serum zinc levels with a median/mode at the lowest 30% of the laboratory reference range; 44 children also had parent/teacher ratings. Serum magnesium levels were normal. Nutritional intake by a parent-answered food frequency questionnaire was unremarkable. Serum zinc correlated at r = -0.45 (p = 0.004) with parent-teacher-rated inattention, even after controlling for gender, age, income, and diagnostic subtype, but only at r = -0.20 (p = 0.22) with CPT omission errors. In contrast, correlation with parent-teacher-rated hyperactivity-impulsivity was nonsignificant in the opposite direction. CONCLUSION: These findings add to accumulating evidence for a possible role of zinc in ADHD, even for middle-class Americans, and, for the first time, suggest a special relationship to inattentive symptoms. They do not establish either that zinc deficiency causes ADHD nor that ADHD should be treated with zinc. Hypothesis-testing clinical trials are needed.