Dietary vitamin C and folic acid supplementation ameliorates the detrimental effects of heat stress in Japanese quail

We evaluated the effects of vitamin C (L-ascorbic acid) and folic acid supplementation on performance, carcass characteristics and concentrations of the oxidative stress markers [malondialdehyde (MDA), homocysteine], adrenocorticotropic hormone (ACTH), vitamins C, E, A, B-12 and folic acid, and mineral status in broiler Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature (34 degrees C, 8 h/d, 0900-1700 h). The birds (n = 150; 10-d-old) kept at 34 degrees C were fed a basal diet (HS group) or the basal diet supplemented with 250 mg of L-ascorbic acid/kg of diet (Vit C group), 1 mg of folic acid/kg of diet (FA group) or both (Vit C + FA group), whereas birds kept at 22 degrees C were fed the basal diet (TN group). Supplementing heat-stressed quail with vitamin C and folic acid improved performance compared to the HS group. Effects generally were greatest in quail supplemented with both. Although supplementation did not consistently restore concentrations to those of the TN group, it increased serum concentrations of the vitamins under study. Furthermore, serum and tissue MDA, homocysteine and ACTH concentrations were lower in the supplemented groups than in the heat-stressed controls. Retention of N, ash, Ca, P, Zn, Fe, Cu and Cr were highest in the Vit C + FA group and lowest in the HS group (P < 0.05). The results of the study indicate that vitamin C and folic acid supplementation attenuates the decline in performance and antioxidant status caused by heat stress. Such supplementation may offer protection against heat stress-related depression in performance of Japanese quail.     

Magnesium proteinate is more protective than magnesium oxide in heat-stressed quail

We evaluated the effects of dietary supplementation with Mg-oxide and Mg-proteinate on performance; nutrient digestibilities; malondialdehyde (MDA) concentrations in serum, liver, and thigh meat; and serum cholesterol and triacylglycerol concentrations in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature. The birds (n = 360; 10 d old) were randomly assigned to 12 treatment groups consisting of 6 replicates of 5 birds each in a 2 x 2 x 3 factorial arrangement (temperature, Mg source, Mg level). Birds were maintained in temperature-controlled rooms at 22 degrees C for 24 h/d or 34 degrees C for 8 h/d (0900-1700 h) and fed a basal diet or that diet supplemented with 1 or 2 g Mg-oxide or Mg-proteinate/kg of diet. Heat exposure decreased (P = 0.0001) live weight gain, feed intake, feed efficiency, and carcass weight in quail fed the basal diet. A linear increase in feed intake (P = 0.008) and body weight (P = 0.001), and improvements in feed efficiency (P = 0.001), carcass weight (P < 0.0001), digestibility of dry matter, organic matter, crude protein, and ether extract were found in Mg-supplemented, heat-stressed quail. The effects of Mg-proteinate were greater than those of Mg-oxide (P < or = 0.0001). Serum Mg (P = 0.001) concentration increased, whereas the concentration of MDA in serum (P = 0.0001), liver (P = 0.04), and thigh meat (P = 0.0001) and serum triglyceride and cholesterol concentrations decreased linearly (P = 0.001) with the level of Mg in the diet. Interactions between dietary Mg source, temperature, and level of supplementation (P < or = 0.05) were found for several variables. Results of the present study suggest that supplementation with Mg-proteinate is more protective than Mg-oxide in reducing the negative effects of heat stress in quail.     

Chromium supplementation can alleviate negative effects of heat stress on egg production,egg quality and some serum metabolites of laying Japanese quail

This study was conducted to determine the effects of Cr (chromium picolinate, CrPic) supplementation at various levels (0, 200, 400, 800 or 1200 microg/kg of diet) on egg production, egg quality and serum concentrations of insulin, corticosterone and glucose in laying Japanese quail (Coturnix coturnix japanica) reared under conditions of heat stress (32.5 degrees C). Laying Japanese quail (n = 150; 45 d old) were divided into five groups of 30 birds. The quail were fed either a control diet containing 965 microg Cr/kg diet or the control diet supplemented with 200, 400, 800 or 1200 microg of Cr/kg diet. Increased supplemental chromium increased body weight (P = 0.05, linear), feed intake (P = 0.05, linear), egg production (P = 0.01, linear) and also improved feed efficiency (P = 0.01, linear). Increased supplemental chromium linearly increased egg weight (P = 0.01), eggshell thickness, egg specific gravity (P = 0.05) and Haugh unit (P = 0.01). Serum insulin concentration increased linearly (P = 0.01), whereas corticosterone and glucose concentration decreased linearly (P = 0.05) as dietary chromium increased. The best results were obtained with 1200 microg Cr/kg diet, and chromium supplementation at such a level can be considered to be protective management practice in a quail diet, reducing the negative effects of heat stress.     

Lycopene supplementation prevents the development of spontaneous smooth muscle tumors of the oviduct in Japanese quail

Leiomyomas (fibroids) are benign tumors of the uterus affecting millions of women. Spontaneous leiomyomas of the oviduct are common tumors of the Japanese quail (Coturnix coturnix japonica), which makes it a good animal model for screening potential agents for testing in the prevention and treatment of human myoma uteri. Because dietary intake of lycopene has been associated with a reduced risk of a variety of human cancers, we investigated the effects of lycopene supplementation on the development of leiomyomas in the oviduct of Japanese quail. We also measured serum levels of oxidative stress markers [malondialdehyde (MDA) and homocysteine], lycopene, vitamins C, E, and A, and tissue biomarkers Bcl-2 and Bax expression. One hundred twenty quails (6 mo old) were assigned to 3 treatment groups consisting of 4 replicates of 10 birds in each group. Birds were fed either a basal diet (group C) or the basal diet supplemented with 100 mg (group L1) or 200 mg (group L2) of lycopene per kilogram of diet. The animals were sacrificed after 285 days and the tumors were identified. Lycopene supplementation decreased the number of leiomyomas compared with control subjects (P=0.056). The tumors in lycopene-fed birds were smaller than those found in control birds (P=0.01). There were no significant differences in the expression of tissue Bcl-2 and Bax among the study groups. Serum vitamins C, E, and A increased (P=0.01), whereas MDA and homocysteine concentrations decreased (P=0.01) with lycopene supplementation. No measurable lycopene could be detected in the serum of control birds, whereas a dose-dependent increase was observed in the serum of lycopene-supplemented birds. The results indicate that dietary supplementation with lycopene reduces the incidence and size of spontaneously occurring leiomyoma of the oviduct in the Japanese quail. Clinical trials should be conducted to investigate the efficacy of lycopene supplementation in the prevention and treatment of uterine leiomyoma in humans.     

Soy content of basal diets determines the effects of supplemental selenium in male mice

The effects of supplemental Se in rodent models may depend upon composition of the basal diet to which it is added. Wild-type male littermates of Transgenic Adenocarcinoma of Mouse Prostate mice were fed until 18 wk of age 1 of 2 Se-adequate stock diets high in soy (HS) or low in phytoestrogens (LP) or the same diets supplemented with 3.0 mg Se/kg diet as seleno-methylselenocysteine. Body and abdominal fat pad weights were lower (P < 0.01) in mice fed the HS diet. Supplemental Se reduced fat pad weights in mice receiving the LP diet but increased body and fat pad weights in mice consuming the HS formulation (P-interaction < 0.005). Serum free triiodothyronine concentrations were unaffected by supplemental Se in mice fed the LP diet but were decreased by Se supplementation of mice given the HS feed (P-interaction < 0.02). Free thyroxine concentrations were higher in mice consuming the HS diet regardless of Se intake (P < 0.001). Hepatic mRNA for iodothyronine deiodinase I was lower (P < 0.001) in mice fed the HS diet. Supplementation of Se increased this mRNA (P < 0.001) in both diet groups. Results from this study show a significant interaction between the composition of basal diets and the effects of supplemental Se with respect to body composition. These findings have important implications for future studies in rodent models of the effects of supplemental Se on heart disease, cancer, diabetes, and other conditions related to body weight and composition.     

Dietary tomato powder supplementation in the prevention of leiomyoma of the oviduct in the Japanese quail

Spontaneous leiomyomas of the oviduct are common tumors of the Japanese Quail (Coturnix coturnix japonica), which makes it a good animal model for screening potential agents for testing in the prevention and treatment of human myoma uteri. We have previously reported a decreased incidence of leiomyomas in the oviduct of Japanese quail with lycopene supplementation. Although the major carotenoid in tomatoes is lycopene, tomatoes also contain other compounds, which may contribute to their health benefit. Therefore, in this study, we investigated the effects of tomato powder supplementation on the development of leiomyomas in the oviduct of Japanese quail. We also measured serum levels of malondialdehyde (MDA), carotenoids, and vitamins C, E, and A. A total of 150 quails (3 mo old) were assigned to 3 treatment groups consisting of 5 replicates of 10 birds in each group. Birds were fed either a basal diet (control group) or the basal diet supplemented with 25 g (Treatment I) or 50 g (Treatment II) of tomato powder (0.8 mg lycopene per g of tomato powder) per kg of diet. The animals were sacrificed after 365 days, and the tumors were identified. Tomato powder supplementation significantly decreased the number of leiomyomas as compared to control birds (P < 0.01). The tumors in tomato powder fed birds were smaller than those found in control birds (P < 0.01). Serum lycopene, lutein, zeaxantin, and vitamins C, E, and A increased (P = 0.01), whereas MDA concentrations decreased (P = 0.01) with tomato powder supplementation. No measurable lycopene could be detected in the serum of control birds, whereas a dose-dependent increase was observed in the serum of birds supplemented with tomato powder. The results indicate that dietary supplementation with tomato powder reduces the incidence and size of spontaneously occurring leiomyoma of the oviduct in the Japanese quail. Clinical trials should be conducted to investigate the efficacy of tomato powder supplementation in the prevention and treatment of uterine leiomyoma in humans.     

Effect of dairy supplementation on body composition and insulin resistance in mice

OBJECTIVE: This study examined whether yogurt supplementation attenuated the weight gain and insulin resistance in mice fed a moderate-fat diet. METHODS: Nine-week-old male mice (F1 BTBR x C57Bl6/J) were housed individually for the duration of the study. After initial measurements of body weight and composition, mice were randomly assigned to receive one of two isocaloric diets (19.4% kcal protein, 45.5% kcal carbohydrate, and 35.1% kcal fat). One diet was supplemented with dried yogurt powder (10.75 g/100 g of diet). In the first experiment, mice received the diets for 4 wk, after which body weight and body composition were reassessed. In the second experiment, an insulin tolerance test was performed at week 4 and glucose uptake in gonadal fat was assessed at week 5. RESULTS: Baseline body weight was not significantly different between control and yogurt mice (P = 0.85). Body weight and fat mass increased significantly over time (P < 0.001) and there was a significant effect of diet on the increase in body weight (P < 0.05) and fat mass (P < 0.001), with the yogurt mice gaining less weight and fat than the control mice. Food intake was not significantly affected by the yogurt supplementation (P = 0.906). Digestive efficiency was significantly lower in the yogurt mice (P < 0.05) due to greater fecal production (P < 0.01). There was no significant effect of diet on the glucose area under the curve during the insulin tolerance test (P = 0.24). Glucose uptake in the gonadal fat was significantly higher in the yogurt mice than in controls under basal (P < 0.05) and insulin-stimulated (P < 0.05) conditions. CONCLUSION: Yogurt supplementation resulted in less weight and fat gain in mice fed isocaloric diets due to a decrease in digestive efficiency. Yogurt also enhanced the uptake of glucose in fat but did not significantly improve insulin sensitivity.     

Dietary Tomato Powder Supplementation in the Prevention of Leiomyoma of the Oviduct in the Japanese Quail

Spontaneous leiomyomas of the oviduct are common tumors of the Japanese Quail (Coturnix coturnix japonica), which makes it a good animal model for screening potential agents for testing in the prevention and treatment of human myoma uteri. We have previously reported a decreased incidence of leiomyomas in the oviduct of Japanese quail with lycopene supplementation. Although the major carotenoid in tomatoes is lycopene, tomatoes also contain other compounds, which may contribute to their health benefit. Therefore, in this study, we investigated the effects of tomato powder supplementation on the development of leiomyomas in the oviduct of Japanese quail. We also measured serum levels of malondialdehyde (MDA), carotenoids, and vitamins C, E, and A. A total of 150 quails (3 mo old) were assigned to 3 treatment groups consisting of 5 replicates of 10 birds in each group. Birds were fed either a basal diet (control group) or the basal diet supplemented with 25 g (Treatment I) or 50 g (Treatment II) of tomato powder (0.8 mg lycopene per g of tomato powder) per kg of diet. The animals were sacrificed after 365 days, and the tumors were identified. Tomato powder supplementation significantly decreased the number of leiomyomas as compared to control birds (P < 0.01). The tumors in tomato powder fed birds were smaller than those found in control birds (P < 0.01). Serum lycopene, lutein, zeaxantin, and vitamins C, E, and A increased (P = 0.01), whereas MDA concentrations decreased (P = 0.01) with tomato powder supplementation. No measurable lycopene could be detected in the serum of control birds, whereas a dose-dependent increase was observed in the serum of birds supplemented with tomato powder. The results indicate that dietary supplementation with tomato powder reduces the incidence and size of spontaneously occurring leiomyoma of the oviduct in the Japanese quail. Clinical trials should be conducted to investigate the efficacy of tomato powder supplementation in the prevention and treatment of uterine leiomyoma in humans.     

Genistein Suppresses Spontaneous Oviduct Tumorigenesis in Quail

Spontaneous leiomyomas of the oviduct are common tumors of the Japanese quail (Coturnix coturnix japonica) and laying hens. This makes it a good animal model for screening potential agents for testing in the prevention and treatment of human myoma uteri. Genistein has been shown to inhibit the growth of various cancer cells. We investigated the effects of genistein supplementation on the development of fibroid tumors in the oviduct, serum oxidative stress markers [malondialdehyde (MDA), 8-isoprostane, 4-hydroxyalkenal (HAE), 8-hydroxy-2′ -deoxyguanosine (8-OHdG) levels], soy isoflavone levels, and tissue biomarkers [Connexin 43 (Cx43), Bcl-2, and Bax and heat shock protein 70 (Hsp70) expression] in Japanese quail. One hundred and fifty quail (12 mo old) were assigned to 3 experimental groups as 5 replicates of pens containing 10 birds in each. Birds were fed either a basal diet or the basal diet supplemented with 400 mg or 800 mg of genistein/kg of diet. The animals were sacrificed after 315 days, and the tumors were identified. Genistein supplementation significantly decreased the incidence of fibroid tumors as compared to control birds (P = 0.04). The tumors in genistein-fed birds were smaller than those found in control birds (P = 0.02). Serum MDA, 8-isoprostane, and HAE levels were lower in treatment groups than in control group (MDA: 2.01 vs. 0.82; 8-isoprostane: 135 vs. 101; HAE: 1.45 vs. 0.73; P ≤ 0.01). The concentrations of serum 8-OHdG, which is a marker of oxidative damage, in the groups were 27.5, 22.4, and 21.3 ng/ml, respectively (P = 0.05). The expression of cell cycle regulatory proteins, Bcl-2, was 4.18 and 4.61 in the genistein groups and 6.21 in the control group, and the expression of Bax was 10.93 and 16.78 in the genistein groups and 7.60 in the control group (P < 0.001 for Bax). Cx43 level was 2.56 and 2.40 in the genistein groups compared with 5.15 in the control group. None of the differences in the Cx43 and Bcl-2 of the groups were significant. The expression of heat shock proteins, Hsp60 and Hsp70, were not different between groups, although Hsp70 level of the genistein groups (19.73) was lower than the control group (27.8). The results indicate that dietary supplementation of genistein reduces the incidence and size of spontaneously occurring leiomyoma of the oviduct in the Japanese quail. Clinical trials should be conducted to investigate the efficacy of genistein supplementation in the prevention and treatment of uterine leiomyoma in humans.     

Isomers of conjugated linoleic acid (CLA) are incorporated into egg yolk lipids by CLA-fed laying hens

This study was designed to determine the amount of conjugated linoleic acid (CLA) incorporated into egg lipids after dietary CLA supplementation. Single Comb White Leghorn laying hens (n = 40; 28 wk old) were randomly assigned to four treatments of varying CLA levels (0, 0.01, 0.5 and 1 g CLA/kg diet). Eggs were collected daily for 36 d. Feed consumption and body weight were monitored. CLA content of egg yolk lipid was analyzed by gas-liquid chromatography. Birds fed 0.5 and 1.0 g CLA/kg feed had significantly more CLA in the egg yolk lipid vs. control and 0.01 g CLA/kg diet groups after 7 d (P < 0.0004). Incorporation of CLA into egg lipid was highest on d 24 and 36. CLA enrichment in egg lipid in the 1.0 g CLA/kg diet group was similar to that in ruminant animal food products, approximately 3 mg CLA/g fat.     

Improvement of leukocyte functions in prematurely aging mice after five weeks of diet supplementation with polyphenol-rich cereals

OBJECTIVE: We investigated the beneficial effects of diet supplementation with two types of cereals naturally rich in polyphenolic compounds on several functions of peritoneal leukocytes from prematurely aging mice (PAM). METHODS: Two-hundred sixty healthy mice, 8 wk of age, were recruited and their behavioral responses were tested in a simple T-maze to identify PAM. Then the mice were fed a diet supplemented with 20% (wt/wt) of two different cereal fractions, named B (wheat germ) and C (buckwheat flour), rich in polyphenols (gallic acid, catechin, p-hydroxybenzoic acid, vanillic acid, p-coumaric acid, sinapic acid, ferulic acid, quercetin, and rutin), or a standard diet (controls) for 5 wk. Several parameters of innate (adherence to tissues, chemotaxis, phagocytosis, microbicidal capacity, and natural killer activity) and acquired immune (lymphoproliferation and interleukin-2 release) responses were measured. RESULTS: The PAM control group showed worse immune functions (P < 0.001 to 0.05) compared with the non-PAM control group. The PAM group that received cereal B showed increases in phagocytosis (P < 0.01), microbicidal activity (P < 0.001 to 0.01), natural killer activity (P < 0.001) and lymphoproliferation in response to lipopolysaccharide (P < 0.01) and interleukin-2 release (P < 0.001), and the PAM group that received cereal C showed a similar pattern, with increases in macrophage chemotaxis (P < 0.01), phagocytosis (P < 0.01), microbicidal activity (P < 0.001 to 0.01), natural killer activity (P < 0.01), lymphoproliferative response to concanavalin A and lipopolysaccharide (P < 0.001), and interleukin-2 release (P < 0.001). CONCLUSIONS: Dietary supplementation with polyphenol-rich cereals appears to have a protective effect on immune cell functions in mice with premature senescence. Thus, regular intake of these compounds could delay normal aging and improve quality of life.     

The Effects of Selenium Supplementation on the Spontaneously Occurring Fibroid Tumors of Oviduct, 8-Hydroxy-2′-Deoxyguanosine Levels,and Heat Shock Protein 70 Response in Japanese Quail

Oxidative stress is known to be an important contributing factor in many chronic diseases. Spontaneously occurring benign oviduct leiomyomas are common tumors of the Japanese quail (Coturnix coturnix japonica), which makes it a good animal model for screening potential agents for testing in the prevention and treatment of human myoma uteri. Since dietary intake of selenium has been associated with a reduced risk of a variety of human cancers, we investigated the effects of selenium supplementation on the development of leiomyomas in the Japanese quail. Potential mechanisms of action of selenium include its antioxidant properties and modulation of heat shock protein 70 (Hsp70); therefore, we measured levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-isoprostane levels, and Hsp70 expression in tissue specimens obtained from the quails. One hundred and eighty quails (8 mo old) were assigned to 3 treatment groups consisting of 60 birds in each group. Birds were fed either a basal diet containing 0.048 mg Se per kg or the basal diet supplemented with 0.2 mg or 0.4 mg of selenium (Selenomax, yeast-bound l-selenomethionine, 60%) per kg of diet. The animals were sacrificed after 250 days, and the tumors were identified. Selenium supplementation did not affect the number of leiomyomas as compared to control subjects (P > 0.05). However, the tumors in selenium fed birds were smaller than those found in control birds (P = 0.01). Serum Se increased (P = 0.01), whereas MDA and 8-isoprostane, 8-OHdG concentrations decreased (P = 0.01) with selenium supplementation (P = 0.01). Selenium supplementation decreased Hsp70 in the tissue of birds. The results indicate that dietary supplementation with selenium reduces the size of spontaneously occurring leiomyoma of the oviduct in the Japanese quail.     

Dietary induction of hypercholesterolemia and atherosclerosis in Japanese quail of strain SEA

Groups of 12 male Japanese quail (Coturnix coturnix japonica) of a strain susceptible to experimental atherosclerosis (SEA) were fed one of three purified diets (one basal and two atherogenic) for 8 wk. The basal diet contained: glucose (46%), soy protein (35%) and beef tallow (10%). Atherogenic diets were prepared by replacing glucose with either 1% cholesterol or 1% cholesterol plus 0.5% cholic acid. Both atherogenic diets induced hypercholesterolemia, with serum cholesterol increased 202 and 336% above basal values for birds fed the cholesterol and cholesterol/cholic acid diets, respectively. The hypercholesterolemia was characterized by an increase in serum levels of very low density and low density lipoprotein cholesterol. No atherosclerotic lesions were found in birds fed the basal diet, but lesion incidence in the dorsal aorta and brachiocephalic arteries was 75 and 100% for birds fed the cholesterol and cholesterol/cholic acid diets, respectively. Arterial scores (percentage of arterial surface area covered by lesions), arterial cholesterol concentration and total liver cholesterol were significantly higher (P less than 0.05) for birds fed the cholic acid containing diet than for those fed the diet having cholesterol only. Severity of atherosclerotic score and arterial cholesterol concentration were positively correlated (P less than 0.01 in both cases) with serum cholesterol concentration. The two indices of the severity of atherosclerosis (arterial score and arterial cholesterol concentration) were highly and linearly correlated (r = 0.88, P less than 0.01). The SEA strain of quail appears to be a promising model for the study of atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Beta-carotene supplementation increases antioxidant capacity of plasma in older women

The antioxidant effect of dietary beta-carotene supplementation on the peroxidation potential of plasma was investigated in a randomized double-blind, placebo-controlled study. Twelve healthy women (62-80 y) supplemented their usual daily diet with 90 mg of beta-carotene (n = 6) or placebo (n = 6) capsules for 3 wk. Plasma concentrations of beta-carotene, alpha- and gamma-tocopherol, ascorbate, urate, bilirubin and in vitro production of phosphatidylcholine hydroperoxides (PC-OOH) and utilization of plasma antioxidants in the presence of 50 mmol/L 2,2'-azobis (2-aminopropane) hydrochloride (AAPH), a free radical generator, at 37 degrees C were measured before and after dietary treatment. Plasma beta-carotene increased from 0.76 +/- 0.16 to 6.45 +/- 1.16 micromol/L (P < 0.05) in supplemented but not placebo-treated subjects. The plasma concentrations of other antioxidants did not change significantly in either group. beta-Carotene supplementation did not affect basal levels of plasma PC-OOH as measured by HPLC post-column chemiluminescence but did affect AAPH-induced production of PC-OOH. Before supplementation, the induction period of plasma PC-OOH production was 2.4 +/- 0.4 h, with levels reaching 5.39 +/- 1.50 micromol/L after 6 h of incubation. After supplementation, the induction period increased significantly to 4.2 +/- 0.4 h (P < 0.01), with a lower PC-OOH production of 2.16 +/- 0.90 micromol/L after 6 h (P < 0.05). In this system, plasma ascorbate concentrations were depleted first, followed by loss of bilirubin and alpha-tocopherol and then by the sequential loss of gamma-tocopherol, urate and beta-carotene. These results indicate that beta-carotene supplementation increases the plasma antioxidant capacity of older women.     

Supplementing young women with both zinc and iron protects zinc-related antioxidant indicators previously impaired by iron supplementation

Iron supplementation impairs antioxidant status, whereas zinc is recognized as an antioxidant micronutrient. We investigated the effect of supplementing both zinc and iron on iron, zinc, and antioxidant status in 18 women (22-31 y) studied during 2 sequential 8-wk periods. From wk 1 to 8, only iron (50 mg/d) (Fe period) was supplemented and from wk 9 to 16, zinc (25 mg/d) (Fe+Zn period) was also given but at a different time of the day. Indicators of iron (serum iron, iron-binding capacity, and serum ferritin), zinc (serum and urinary zinc), and antioxidant status [ferric-reducing ability of plasma (FRAP); erythrocyte osmotic fragility (EOF); erythrocyte aminolevulinic acid dehydratase (delta-ALAD) activity, and in vitro zinc-delta-ALAD activation (Zn-delta-ALAD%)] were measured at baseline and after each supplementation period. Fe period modified indicators of iron status as expected (P < 0.05) but did not affect indicators of zinc status. Fe+Zn period did not affect indicators of iron status but increased serum and urinary zinc (P < 0.02). Antioxidant status was impaired after the Fe period, as indicated by decreased FRAP (P < 0.005) and delta-ALAD activity (P < 0.05) and increased EOF (P < 0.01). After the Fe+Zn period, FRAP values tended to increase (P = 0.1), delta-ALAD activity and EOF returned to baseline values, and Zn-delta-ALAD% decreased (P < 0.001) compared with baseline. In conclusion, supplementing young women with both zinc and iron protects zinc-related antioxidant indicators previously impaired by iron supplementation without impairment of iron status.     

Supplemental zinc lowers measures of iron status in young women with low iron reserves

Zinc and iron compete during intestinal absorption, but postabsorptive interactions between these nutrients are less clear. Understanding these interactions is important to determine when supplementation with iron or zinc is proposed. The effect of zinc supplementation (22 mg Zn/d as zinc gluconate) or of iron supplementation (100 mg Fe/d as ferrous sulfate) for 6 wk on iron and zinc metabolism and absorption was evaluated in young women with low iron reserves. Young adult women (ages 20-28 y), nonanemic but with low iron stores (plasma ferritin< 20 microg/L), participated in the 70-d study. The women were divided in two groups (zinc-supplemented, n = 11; iron-supplemented, n = 12). The supplements were taken at bedtime. Iron and zinc biochemical indices and intestinal absorption were measured on d 1 and 56. Radioiron and stable isotopes of zinc were used to measure iron and zinc absorption from a test meal. In the iron-supplemented group, blood hemoglobin, plasma ferritin and the percentage of transferrin saturation increased (P < 0.01). Zinc indices did not change. In the zinc-supplemented group, plasma ferritin and the percentage of transferrin saturation decreased (P < 0.05), whereas the plasma transferrin receptor and erythrocyte zinc protoprophyrin levels increased (P < 0.05). Plasma and urinary zinc also increased (P < 0.01). Iron absorption (%) from the test meal increased (P < 0.01), whereas zinc absorption (%) decreased (P < 0.01) compared with baseline in the Zn-supplemented women. Our results indicate that the use of iron supplements in women with marginal iron status improves iron indices with no effect on zinc status. However, use of a modest zinc supplement improves zinc indices, but also appears to induce a cellular iron deficiency and, possibly, further reduce iron status.     

Maternal iron and zinc supplementation during pregnancy affects body weight and iron status in rat pups at weaning

Pregnant women worldwide are frequently iron (Fe) and zinc (Zn) deficient. Therefore, cosupplementation with Fe and Zn during pregnancy is common. Although Fe supplementation programs are successful, studies suggest that Zn supplementation negatively affects maternal Fe metabolism. However, little is known about the effects of maternal Fe or Zn supplementation on Fe metabolism in the offspring. We developed a rat model to investigate if Fe and/or Zn supplementation during pregnancy affects regulation of nonheme Fe absorption and Fe status in offspring and if these effects are dependent upon maternal Fe and Zn status at conception. Control (C; fed a Fe- and Zn-adequate diet; 75 and 25 μg/g, respectively) or Fe- and Zn-deficient (D; fed a Fe- and Zn-deficient diet; 12 and 10 μg/g, respectively) rats were supplemented with Fe (27 mg/wk), Zn (4.5 mg/wk), Fe+Zn (27 mg Fe, 4.5 mg Zn/wk), or placebo throughout pregnancy. At postnatal d 21, body weight (BW), hemoglobin (Hb), hematocrit (Hct), liver and intestine Fe concentration, liver hepcidin, and intestine Fe transporter expression were determined in pups. Zn supplementation of C dams decreased pup BW (P < 0.0001), whereas it increased pup BW in D dams (P < 0.0001). Zn supplementation of C dams did not affect Hb and Hct in pups but increased the liver Fe concentration (P = 0.0002). However, Zn supplementation of D dams decreased hepcidin expression in their offspring (P < 0.0001). In C dams, Fe and Fe+Zn supplementation decreased ferroportin levels in pup intestine compared with pups from unsupplemented dams (P < 0.05). In conclusion, Zn supplementation of dams with adequate Fe and Zn status increases offspring liver Fe concentration and postnatally compromises BW. Therefore, potential adverse effects of Zn supplementation should be evaluated.     

Lutein and zeaxanthin concentrations in plasma after dietary supplementation with egg yolk.

BACKGROUND: The food matrix in which carotenoids are found affects their bioavailability. Lutein and zeaxanthin are abundant in egg yolks and accumulate in the macular region of the retina, where they may affect visual function. OBJECTIVE: We sought to determine whether plasma lutein and zeaxanthin concentrations are elevated after dietary supplementation with egg yolk. DESIGN: Eleven moderately hypercholesterolemic men and women consumed 2 separate baseline diets, which contained 29-33% of energy as total fat, with 20% of energy as either beef tallow or corn oil. These diets were supplemented with cooked chicken egg yolks (1.3 egg yolks/d for an intake of 10.4 MJ). Each subject consumed all 4 diets. Each diet was consumed for 4.5 wk, with a washout period of >/=2 wk between diet phases. At the end of each diet phase, fasting morning plasma samples were collected and stored for carotenoid analysis by HPLC. Commercial chicken egg yolks were analyzed for carotenoids and cholesterol. RESULTS: Egg yolk supplementation of the beef tallow diet increased plasma lutein by 28% (P < 0.05) and zeaxanthin by 142% (P < 0.001); supplementation of the corn oil diet increased plasma lutein by 50% (P < 0.05) and zeaxanthin by 114% (P < 0.001). Changes in plasma lycopene and beta-carotene were variable, with no consistent trend. Egg yolk supplementation increased plasma LDL-cholesterol concentrations by 8-11% (P < 0.05). CONCLUSIONS: Egg yolk is a highly bioavailable source of lutein and zeaxanthin. The benefit of introducing these carotenoids into the diet with egg yolk is counterbalanced by potential LDL-cholesterol elevation from the added dietary cholesterol.     

Addition of oat hulls to an extruded rice-based diet for weaner pigs ameliorates the incidence of diarrhoea and reduces indices of protein fermentation in the gastrointestinal tract

An experiment was conducted to determine whether adding oat hulls to weaner pig diets based on extruded rice or unprocessed wheat influenced post-weaning diarrhoea (PWD) and protein fermentation in the large intestine. Ninety-six male piglets (5.16 (SEM 0.08) kg) were allocated to (i) extruded rice plus animal proteins (RAP); (ii) RAP with added oat hulls (20 g/kg); (iii) wheat plus animal proteins (WAP); (iv) WAP with added oat hulls (20 g/kg). Blood and faecal samples were collected on days 7 and 14 after weaning at about age 21 d. Pigs fed RAP had more PWD than pigs fed WAP (P < 0.05). Oat hull supplementation to diet RAP decreased the incidence of PWD (P < 0.05). The total-tract digestibility of DM, starch and energy was higher in rice-based diets than in wheat-based diets (P < 0.001); however, oat hulls decreased digestibility of DM and gross energy (P < 0.001). Pigs fed RAP had higher plasma creatinine concentrations (P < 0.01), which were positively correlated to cumulative beta-haemolytic Escherichia coli scores after weaning (R2 0.928; P = 0.015). Addition of oat hulls decreased plasma urea concentrations only in pigs fed RAP (interaction; P < 0.05). Pigs fed RAP had lower faecal total biogenic amine concentrations than pigs fed WAP (P < 0.001). Oat hull supplementation tended to decrease total biogenic amine concentrations (P = 0.103). These data indirectly suggest that a mostly insoluble dietary fibre source such as oat hulls can decrease PWD in dietary situations where there may be a misbalance of carbohydrate to protein entering the hindgut.     

Effect of zinc supplementation between 1 and 6 mo of life on growth and morbidity of Bangladeshi infants in urban slums

BACKGROUND: Evidence for an effect of zinc supplementation on growth and morbidity in very young infants in developing countries is scarce and inconsistent. OBJECTIVE: We assessed the effect of zinc supplementation on growth and morbidity in poor Bangladeshi infants aged 4-24 wk. DESIGN: Infants from Dhaka slums were enrolled at 4 wk of age and randomly assigned to receive 5 mg elemental Zn/d (n = 152) or placebo (n = 149) until 24 wk of age. They were followed weekly for information on compliance and morbidity; anthropometric measurements were performed monthly. Serum zinc was assessed at baseline and at 24 wk of age. RESULTS: At 24 wk of age, serum zinc concentrations were higher in the zinc than in the placebo group (13.3 +/- 3.8 and 10.7 +/- 2.9 micro mol/L, respectively; P < 0.001). Significantly greater weight gains were observed in the zinc than in the placebo group for 43 infants who were zinc deficient (< 9.18 micro mol/L) at baseline (3.15 +/- 0.77 and 2.66 +/- 0.80 kg, respectively; P < 0.04). In the other infants, no significant differences were observed in mean weight and length gains during the study period. Zinc-deficient infants showed a reduced risk of incidence of acute lower respiratory infection after zinc supplementation (relative risk: 0.30; 95% CI: 0.10, 0.92); among the non-zinc-deficient infants there were no significant differences between treatment groups. CONCLUSIONS: Zinc-deficient Bangladeshi infants showed improvements in growth rate and a reduced incidence of acute lower respiratory infection after zinc supplementation. In infants with serum zinc concentrations > 9.18 micro mol/L, supplementation improved only biochemical zinc status.