Influence of cow or goat milk consumption on antioxidant defence and lipid peroxidation during chronic iron repletion

Despite Fe deficiency and overload having been widely studied, no studies are available about the influence of milk consumption on antioxidant defence and lipid peroxidation during the course of these highly prevalent cases. The objective of the present study was to assess the influence of cow or goat milk-based diets, either with normal or Fe-overload, on antioxidant defence and lipid peroxidation in the liver, brain and erythrocytes of control and anaemic rats after chronic Fe repletion. Weanling male rats were randomly divided into two groups: a control group receiving a normal-Fe diet (45 mg/kg) and an anaemic group receiving a low-Fe diet (5 mg/kg) for 40 d. Control and anaemic rats were fed goat or cow milk-based diets, either with normal Fe or Fe-overload (450 mg/kg), for 30 or 50 d. Fe-deficiency anaemia did not have any effect on antioxidant enzymes or lipid peroxidation in the organs studied. During chronic Fe repletion, superoxide dismutase (SOD) activity was higher in the group of animals fed the cow milk diet compared with the group consuming goat milk. The slight modification of catalase and glutathione peroxidise activities in animals fed the cow milk-based diet reveals that these enzymes are unable to neutralise and scavenge the high generation of free radicals produced. The animals fed the cow milk diet showed higher rates of lipid peroxidation compared with those receiving the goat milk diet, which directly correlated with the increase in SOD activity. It was concluded that goat milk has positive effects on antioxidant defence, even in a situation of Fe overload, limiting lipid peroxidation.     

Anti-anaemia efficacy of β-lactoglobulin hydrolysate-iron complex on iron-deficient anaemic rats

Purpose

The effects of orally administered β-lactoglobulin hydrolysate-iron complex (β-LGH-Fe) on haematological and biochemical parameters in anaemic rats were evaluated. Female weaning Sprague–Dawley rats were fed with iron-deficient diet to induce iron deficiency anaemia. After 6 weeks, the obtained anaemic rats were divided into five groups: iron deficiency control group (iron-deficient diet without β-LGH-Fe complex supplementation, IDC); three groups supplemented with different dosages of β-LGH-Fe complex (0.5 mg Fe/kg BW, iron-deficient diet with low β-LGH-Fe, IDLFe; 2.0 mg Fe/kg BW, iron-deficient diet with medium β-LGH-Fe, IDMF; 4.0 mg Fe/kg BW, iron-deficient diet with high β-LGH-Fe, IDHFe); and ferrous sulphate-supplemented group at a dosage of 2.0 mg Fe/kg BW.

Results

β-LGH-Fe complex could significantly improve hematocrit and haemoglobin decrease, and normalise the serum iron level, total iron-binding capacity and transferrin saturation of anaemic rats in a dose-dependent manner. Serum ferritin content and hepatic nonheme iron level were also increased. In addition, the antioxidant enzyme activities of superoxidase dismutase, catalase and glutathione peroxidase in both plasma and liver homogenate were improved. The production of malondialdehyde and pro-inflammatory cytokines (TNF-α and IL-6) decreased.

Conclusions

It suggests that β-LGH-Fe complex can ameliorate iron deficiency anaemia, which might make it a potential ingredient with anti-anaemia activity.     

Dietary folic acid intake differentially affects methionine metabolism markers and hippoccampus morphology in aged rats

Purpose

Folic acid (FA) is an emerging nutritional factor in the pathogenesis of diverse neurodegenerative disorders by still unknown mechanisms. The hippocampus is altered during the loss of cognitive abilities in humans and selectively affected when homocysteine increases. The aim was to evaluate the potential protective role of folic acid in the maintenance of biochemical markers related to the methionine cycle, as well as the integrity of the hippocampus as part of the brain in aged rats.

Methods

Male Sprague–Dawley rats (18 months old) were assigned to four different folic acid groups (0 mg FA/kg diet, deficient; 2 mg FA/kg diet, control; 8 mg FA/kg diet, moderate supplementation; 40 mg FA/kg diet, extra supplementation) for 30 days. We evaluated several parameters related to the methionine cycle. In addition, hippocampus areas were immunostained for specific neuronal markers and astrocytes.

Results

Serum folate levels increased according to FA dietary level (p < 0.01). There was a significant increase in the serum homocysteine concentrations in the folic acid-deficient diet group (p < 0.01). However, brain S-adenosylmethionine and S-adenosylhomocysteine did not differ significantly between the folic acid groups. Consequently, the methylation ratio was also unchanged. The morphometric analysis did not show any differences in the number of neurons and astrocytes between groups, except when comparing the folic acid-deficient diet versus folic acid-supplemented diet in the striatum of the hippocampus.

Conclusions

Clearly, the dietary FA deficiency negatively affects the methionine metabolism biomarkers, while excessive supplementation seems to be unnecessary for optimal maintenance of the methylation cycle and hippocampus integrity.     

Diet-induced obese rats have higher iron requirements and are more vulnerable to iron deficiency

Purpose

Since obesity is associated with poorer iron status, the effects of diet-induced obesity on iron status and iron-regulatory pathways were examined.

Methods

Weanling male diet-induced obese sensitive (n = 12/diet group) and resistant (n = 12/diet group) rats were fed one of four high-fat, high-energy diets supplemented with 5 (5Fe, low), 15 (15Fe, marginal), 35 (35Fe, normal) or 70 (70Fe, high) mg iron/kg diet for 12 weeks. At the end of the study, rats in each diet group were categorised as obese (>19 %) or lean (<17 %) based on percentage body fat.

Results

Obese rats gained more weight, had larger total lean mass, consumed more food and showed greater feed efficiency compared with lean rats. Obese rats fed the 5Fe and 15Fe diets had poorer iron status than lean rats fed the same diet. Obese 5Fe rats had lower serum iron and more severe iron-deficiency anaemia. Obese 15Fe rats had lower mean corpuscular haemoglobin and liver iron concentrations. Hepcidin mRNA expression in liver and adipose tissue was similar for obese and lean rats. Iron concentration and content of the iron transporters divalent metal transporter 1 and ferroportin 1 in duodenal mucosa were also similar.

Conclusions

Obese rats that were larger, regardless of adiposity, had higher iron requirements compared with lean rats that appeared independent of hepcidin, inflammation and intestinal iron absorption. Higher iron requirements may have resulted from larger accretion of body mass and blood volume. Greater food consumption did not compensate for the higher iron needs, indicating increased susceptibility to iron deficiency.     

The effect of high doses of folic acid and iron supplementation in early-to-mid pregnancy on prematurity and fetal growth retardation: the mother–child cohort study in Crete, Greece (Rhea study)

Purpose

We examined whether high doses of folic acid and iron supplementation in early-to-mid pregnancy affect the risk of preterm birth, low birth weight, and small for gestational age neonates, in the mother–child cohort in Crete, Greece (Rhea study).

Methods

We included 1,279 women with singleton pregnancies with complete data on supplements use in early-to-mid pregnancy and birth outcomes. Anthropometric measurements at birth were obtained from medical records. Red blood cell folate concentrations in cord blood were measured in a subsample of the study population (n = 58).

Results

Sixty-six percent of the study participants reported high doses of supplemental folic acid use (5 mg/day), while 21 % reported excessive doses of folic acid use (>5 mg/day) in early-to-mid pregnancy. Daily intake of 5-mg supplemental folic acid was associated with a 31 % decrease in the risk of preterm birth (RR, 0.69; 95 % CI, 0.44, 0.99), 60 % decrease in the risk of delivering a low birth weight neonate (RR, 0.40; 95 % CI, 0.21, 0.76), and 66 % decrease in the risk of delivering a small for gestational age (SGA) neonate (RR, 0.34; 95 % CI, 0.16, 0.73). Daily doses of iron supplementation more than 100 mg were associated with a twofold increased risk for SGA neonates (RR, 2.14; 95 % CI, 0.99, 5.97).

Conclusion

These findings suggest that high daily doses of supplementary folic acid in early-to-mid pregnancy may be protective for preterm birth, low birth weight, and small for gestational age neonates, while high daily doses of supplementary iron may be harmful for fetal growth.     

Ferrous ammonium phosphate (FeNH4PO4) as a new food fortificant: iron bioavailability compared to ferrous sulfate and ferric pyrophosphate from an instant milk drink

Purpose

The main purpose of this study was to establish bioavailability data in humans for the new (Fe) fortification compound ferrous ammonium phosphate (FAP), which was specially developed for fortification of difficult-to-fortify foods where soluble Fe compounds cannot be used due to their negative impact on product stability.

Methods

A double-blind, randomized clinical trial with cross-over design was conducted to obtain bioavailability data for FAP in humans. In this trial, Fe absorption from FAP-fortified full-cream milk powder was compared to that from ferric pyrophosphate (FPP) and ferrous sulfate. Fe absorption was determined in 38 young women using the erythrocyte incorporation dual stable isotope technique (⁵⁷Fe, ⁵⁸Fe).

Results

Geometric mean Fe absorption from ferrous sulfate, FAP and FPP was 10.4, 7.4 and 3.3 %, respectively. Fe from FAP was significantly better absorbed from milk than Fe from FPP (p < 0.0001). Fe absorption from FAP was significantly lower than Fe absorption from ferrous sulfate, which was used as water-soluble reference compound (p = 0.0002). Absorption ratios of FAP and FPP relative to ferrous sulfate as a measure of relative bioavailability were 0.71 and 0.32, respectively.

Conclusions

The results of the present studies show that replacing FPP with FAP in full-cream milk could significantly improve iron bioavailability.     

Low folic acid status and its association with anaemia in urban adolescent girls and women of childbearing age in Sri Lanka

Folic acid deficiency is implicated in the aetiology of nutritional anaemia and adverse pregnancy outcomes for the fetus. Data on folic acid status among adolescent girls and non-pregnant, non-lactating young women are limited. We assessed folic acid status in a random sample of 552 subjects (277 adolescent girls aged 15-18.9 years and 275 women aged 19-30 years) living in Colombo, Sri Lanka. The association of low folic acid status with anaemia was evaluated. Socio-economic, food intake and anthropometric data were obtained. Hb, serum folic acid, vitamin B12 and ferritin and plasma homocysteine concentrations were measured. Forty-three per cent of subjects studied had low serum folic acid concentrations (<3 ng/ml) and 47 % had low Fe stores (serum ferritin <20 microg/l). Overall prevalence of anaemia was 12.9 %, and 43.9 % of anaemic subjects had both low folic acid status and depleted Fe stores (serum ferritin <12 microg/l). Both low folate status and depleted Fe stores were significantly associated with anaemia (odds ratio = 2.32; 95 % CI 1.34, 4.01 and odds ratio = 5.98; 95 % CI 3.36, 10.63, respectively). Serum folic acid concentration was associated (r = 0.108, P = 0.015) with folate intake as indicated by a computed folate index. Folate index was associated inversely with household size and positively with economic status and education level. In this study population low folic acid status, besides depleted Fe stores, was associated with anaemia. The high prevalence of low folic acid status observed highlights the need for nutrition education to improve intakes of folate, Fe and other micronutrients among adolescent girls and young women.     

Effects of l-arginine supplementation on blood flow, oxidative stress status and exercise responses in young adults with uncomplicated type I diabetes

Background and aims

Vascular disease is the principal cause of death and disability in patients with diabetes, and endothelial dysfunction seems to be the major cause in its pathogenesis. Since l-arginine levels are diminished in conditions such as type 1 and type 2 diabetes, in this work we aimed to verify the effects of l-arginine supplementation (7 g/day) over the endothelial function and oxidative stress markers in young male adults with uncomplicated type 1 diabetes. We also investigated the influences of l-arginine administration on vascular/oxidative stress responses to an acute bout of exercise.

Methods

Ten young adult male subjects with uncomplicated type 1 diabetes and twenty matched controls volunteered for this study. We analysed the influence of l-arginine supplementation (7 g/day during 1 week) over lower limb blood flow (using a venous occlusion plethysmography technique), oxidative stress marker (TBARS, Carbonyls), anti-oxidant parameters (uric acid and TRAP) and total tNOx in rest conditions and after a single bout of submaximal exercise (VO₂ at 10 % below the second ventilatory threshold). Data described as mean ± standard error (SE). Alpha level was P < 0.05.

Results

Glycaemic control parameters were altered in type 1 diabetic subjects, such as HbA1c (5.5 ± 0.03 vs. 8.3 ± 0.4 %) and fasted glycaemia (94.8 ± 1.4 vs. 183 ± 19 mg/dL). Oxidative stress/damage markers (carbonyls and TBARS) were increased in the diabetic group, while uric acid was decreased. Rest lower limb blood flow was lower in type 1 diabetic subjects than in healthy controls (3.53 ± 0.35 vs. 2.66 ± 0.3 ml 100 ml^?¹ min^?¹). l-Arginine supplementation completely recovered basal blood flow to normal levels in type 1 diabetics’ subjects (2.66 ± 0.3 to 4.74 ± 0.86 ml 100 ml^?¹ min^?¹) but did not interfere in any parameter of redox state or exercise.

Conclusion

Our findings highlight the importance of l-arginine for the improvement of vascular function in subjects with diabetes, indicating that l-arginine supplementation could be an essential tool for the treatment for the disease complications, at least in non-complicated diabetes. However, based on our data, it is not possible to draw conclusions regarding the mechanisms by which l-arginine therapy is inducing improvements on cardiovascular function, but this important issue requires further investigations.     

Different postprandial acute response in healthy subjects to three strawberry jams varying in carbohydrate and antioxidant content: a randomized,crossover trial

Purpose

Dietary food composition influences postprandial glucose homeostasis. Thus, the objective was to investigate the effects of an acute intake of three different types of strawberry jam, differing in carbohydrate and antioxidants content, on postprandial glucose metabolism, lipid profile, antioxidant status, and satiety.

Methods

Sixteen healthy adults participated in a randomized, crossover, double-blind study with three arms, receiving 60 g of three different strawberry jams. Blood samples were collected at fasting and at 30, 60, 90, and 120 min after its intake. Blood analyses were performed with validated procedures and satiety was estimated with visual analogue scale (VAS).

Results

Blood glucose concentrations were maintained at normal values and without peaks within the 2 h after consumption of low-sugar jams. However, blood glucose and insulin were significantly higher at 30 and 60 min after high-sugar (HS) jam intake versus both low-sugar jams. Furthermore, HS jam produced more satisfaction at short time, but decreased as soon as blood glucose concentration began to decrease. Moreover, HS ingestion produced lower free fatty acid levels (p < 0.05) throughout the trial with respect both the low-sugar jams. However, no additional benefits on oxidative status (malondialdehyde, glutathione peroxidase, total antioxidant capacity, and uric acid), glucose, lipid, and satiety variables were observed due to the inclusion of an antioxidant to low-sugar jam.

Conclusions

This study reinforces the idea that products without added sugars are appropriate for the management of glycemic alterations and provides further insight into the effect of natural antioxidants as a functional ingredient on oxidative status and related metabolic disturbances. Registered at www.clinicaltrials.gov as NCT01684332.     

The effect of almonds on inflammation and oxidative stress in Chinese patients with type 2 diabetes mellitus: a randomized crossover controlled feeding trial

Purpose

Almond consumption is associated with ameliorations in obesity, hyperlipidemia, hypertension, and hyperglycemia. The hypothesis of this 12-week randomized, crossover, controlled feeding trial was that almond consumption would ameliorate inflammation and oxidative stress in Chinese patients with type 2 diabetes mellitus (T2DM) (9 M, 11 F; 58 years; BMI: 26 kg/m²) with mild hyperlipidemia.

Methods

After a 2-week run-in period, the patients were assigned to either a control NCEP step II diet (control diet) or almond diet for 4 weeks with a 2-week washout period between alternative diets. Almonds approximately at 56 g/day were added to the control diet to replace 20 % of total daily calorie intake.

Results

As compared to the control diet, the almond diet decreased IL-6 by a median 10.3 % (95 % confidence intervals 5.2, 12.6 %), CRP by a median 10.3 % (?24.1, 40.5), and TNF-α by a median 15.7 % (?0.3, 29.9). The almond diet also decreased plasma protein carbonyl by a median 28.2 % (4.7, 38.2) as compared to the C diet but did not alter plasma malondialdehyde. The A diet enhanced the resistance of LDL against Cu²⁺-induced oxidation by a median 16.3 % (7.4, 44.3) as compared to the C diet. Serum intercellular adhesion molecule-1 and vascular adhesion molecule-1 were not changed by both diets.

Conclusions

Our results suggested that incorporation of almonds into a healthy diet could ameliorate inflammation and oxidative stress in patients with T2DM.     

Differential effects of high-carbohydrate and high-fat diets on hepatic lipogenesis in rats

Purpose

Hepatic fatty acid synthesis is influenced by several nutritional and hormonal factors. In this study, we have investigated the effects of distinct experimental diets enriched in carbohydrate or in fat on hepatic lipogenesis.

Methods

Male Wistar rats were divided into four groups and fed distinct experimental diets enriched in carbohydrates (70 % w/w) or in fat (20 and 35 % w/w). Activity and expression of the mitochondrial citrate carrier and of the cytosolic enzymes acetyl-CoA carboxylase and fatty acid synthetase were analyzed through the study with assessments at 0, 1, 2, 4, and 6 weeks. Liver lipids and plasma levels of lipids, glucose, and insulin were assayed in parallel.

Results

Whereas the high-carbohydrate diet moderately stimulated hepatic lipogenesis, a strong inhibition of this anabolic pathway was found in animals fed high-fat diets. This inhibition was time-dependent and concentration-dependent. Moreover, whereas the high-carbohydrate diet induced an increase in plasma triglycerides, the high-fat diets determined an accumulation of triglycerides in liver. An increase in the plasmatic levels of glucose and insulin was observed in all cases.

Conclusions

The excess of sucrose in the diet is converted into fat that is distributed by bloodstream in the organism in the form of circulating triglycerides. On the other hand, a high amount of dietary fat caused a strong inhibition of lipogenesis and a concomitant increase in the level of hepatic lipids, thereby highlighting, in these conditions, the role of liver as a reservoir of exogenous fat.     

Low iron status as a factor of increased bone resorption and effects of an iron and vitamin D-fortified skimmed milk on bone remodelling in young Spanish women

Purpose

This study aimed to determine whether there is a relationship between iron status and bone metabolism, and to compare the effects of the consumption, as part of the usual diet, of an iron or iron and vitamin D-fortified skimmed milk on bone remodelling in iron-deficient women.

Methods

Young healthy iron-deficient or iron-sufficient women (serum ferritin ≤30 ng/mL or >30 ng/mL, respectively) were recruited. Iron-deficient women were assigned to a nutritional intervention consisting of a randomised, controlled, double-blind, parallel design trial of 16 weeks during winter. They consumed, as part of their usual diet, an iron (Fe group, n = 54) or iron and vitamin D-fortified (Fe+D group, n = 55) flavoured skimmed milk (iron, 15 mg/day; vitamin D₃, 5 μg/day, 200 IU). The iron-sufficient women followed their usual diet without supplementation (R group, n = 56). Dietary intake, body weight, iron biomarkers, 25-hydroxyvitamin D (25OHD), parathyroid hormone (PTH), procollagen-type 1 N-terminal propeptide (P1NP), and aminoterminal telopeptide of collagen I (NTx) were determined.

Results

Negative correlations were found between baseline log-ferritin and log-NTx (p < 0.001), and between transferrin and P1NP (p = 0.002). Serum 25OHD increased (from 62 ± 21 to 71 ± 21 nmol/L, mean ± SD, p < 0.001) while P1NP and NTx decreased in Fe+D during the assay (p = 0.004 and p < 0.001, respectively). NTx was lower in Fe+D compared to Fe at week 8 (p < 0.05) and was higher in Fe and Fe+D compared to R throughout the assay (p < 0.01). PTH did not show changes.

Conclusions

Iron deficiency is related with higher bone resorption in young women. Consumption of a dairy product that supplies 5 μg/day of vitamin D₃ reduces bone turnover and increases circulating 25OHD to nearly reach an optimal vitamin D status, defined as 25OHD over 75 nmol/L.     

Blood trace minerals concentrations and oxidative stress in patients with obstructive sleep apnea

Background

Obstructive sleep apnea (OSA) is associated with increased oxidative stress. Certain essential trace minerals have shown to play an important role in the maintenance of redox homeostasis. We determined the concentrations of trace minerals in OSA patients and assessed their relationships to OSA severity as indicated by the apnea/hypopnea index (AHI).

Methods

We enrolled 44 patients with newly diagnosed mild to moderate OSA and 20 without OSA. The following parameters were measured: polysomnographic values of nocturnal sleep; plasma trace minerals zinc (Zn), copper (Cu), iron (Fe), and erythrocyte selenium (Se); oxidative stress status; and plasma high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-α (TNF-α).

Results

Compared to controls matched for age, gender, and body mass index, OSA patients had lower concentrations of plasma Zn and erythrocyte Se and higher plasma concentrations of Cu and Fe. OSA patients had significantly higher plasma concentrations of hs-CRP, TNF-α, and malondialdehyde (MDA), and lower erythrocyte antioxidant enzyme glutathione peroxidase (GPx) and superoxide dismutase activities. Significant differences in all the above parameters were also found in patients with moderate OSA compared to those with mild OSA. Furthermore, AHI values correlated significantly with neck circumference, GPx activity, and MDA, hs-CRP, and TNF-α concentrations in OSA patients. AHI values were also negatively associated with concentrations of plasma Zn and erythrocyte Se, but were positively linked to plasma concentrations of Fe and Cu.

Conclusions

Abnormal concentrations of these trace minerals may reflect oxidative damage and inflammatory response, thus increasing the severity of OSA.     

Promotive effects of resistant maltodextrin on apparent absorption of calcium, magnesium, iron and zinc in rats

Background

It has been reported that low-viscous and fermentable dietary fiber and nondigestible oligosaccharides enhance mineral absorption. Resistant maltodextrin, nonviscous, fermentable and soluble source of dietary fiber, has several physiological functions. However, influence of resistant maltodextrin on mineral absorption is unclear.

Aim of the study

We conducted balance studies in rats to investigate effects of resistant maltodextrin and hydrogenated resistant maltodextrin on apparent mineral absorption.

Methods

In experiment 1 (Exp. 1), 40 rats were fed test diets based on AIN-93G with or without resistant maltodextrin or hydrogenated resistant maltodextrin for 2 weeks. In experiment 2 (Exp. 2), 32 rats were cecectomized (CX) or sham-operated (Sham) and fed diets with or without hydrogenated resistant maltodextrin for 1 week.

Results

In Exp. 1, ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin dose-dependently enhanced apparent absorption rates of Ca, Mg, Fe and Zn, and increased cecal fermentation with cecal expansion. In Exp. 2, the absorption rates of Ca and Mg were significantly enhanced by ingestion of hydrogenated resistant maltodextrin in Sham group but not in CX group. The promotion of Fe and Zn absorption was not affected by cecectomy.

Conclusion

Ingestion of resistant maltodextrin and hydrogenated resistant maltodextrin increased apparent Ca and Mg absorptions dependent on cecal fermentation, while other mechanisms may also be involved in promotion of apparent Fe and Zn absorption by resistant maltodextrin.     

Increased hepatic de novo lipogenesis and mitochondrial efficiency in a model of obesity induced by diets rich in fructose

Purpose

To assess hepatic de novo lipogenesis and mitochondrial energetics as well as whole-body energy homeostasis in sedentary rats fed a fructose-rich diet.

Methods

Male rats of 90 days of age were fed a high-fructose or control diet for 8 weeks. Body composition, energy balance, oxygen consumption, carbon dioxide production, non-protein respiratory quotient, de novo lipogenesis and insulin resistance were measured. Determination of specific activity of hepatic enzymes of de novo lipogenesis, mitochondrial mass, oxidative capacity and degree of coupling, together with parameters of oxidative stress and antioxidant defence, was also carried out.

Results

Body energy and lipid content as well as plasma insulin and non-esterified fatty acids were significantly higher in fructose-fed than in control rats. Significantly higher rates of net de novo lipogenesis and activities of hepatic lipogenic enzymes fatty acid synthase and stearoyl CoA desaturase-1 were found in fructose-fed rats compared to controls. Mitochondrial protein mass and degree of coupling were significantly higher in fructose-fed rats compared to controls. Hepatic mitochondria showed oxidative damage, both in the lipid and in the protein component, together with decreased activity of antioxidant defence.

Conclusion

Liver mitochondrial compartment is highly affected by fructose feeding. The increased mitochondrial efficiency allows liver cells to burn less substrates to produce ATP for de novo lipogenesis and gluconeogenesis. In addition, increased lipogenesis gives rise to whole body and ectopic lipid deposition, and higher mitochondrial coupling causes mitochondrial oxidative stress.     

Dietary fat quality in regular fat diets has minor effects on biomarkers of inflammation in obese Zucker rats

Purpose

Adipose tissue-associated chronic inflammation is involved in the pathogenesis of obesity-related diseases. Dietary fatty acids are known to influence inflammatory processes. The aim of this study was to investigate, whether diets with regular fat contents but variable fat qualities affect adipose tissue-associated inflammation through the fatty acid composition of mesenteric adipose tissue (MAT).

Methods

Obese Zucker rats were fed diets containing 7 % wt:wt rapeseed oil, corn oil, or lard for 10 weeks. Fatty acid composition and endocrine function regarding adipokines and cytokines of MAT, number of total CD3⁺ T cells, and cytokine secretion of mesenteric lymph node (MLN)-derived lymphocytes were determined. Local effects in MAT and MLN were compared to systemic effects assessed in serum and peripheral blood mononuclear cells.

Results

Fatty acid composition of MAT reflected dietary fatty acid intake, without affecting endocrine function. Feeding the lard diet for 10 weeks increased the serum adiponectin and TNF-α secretion of blood lymphocytes, whereas CD3⁺ T cells in blood were decreased. No effects were seen for the secretion of adipokines and cytokines from MAT, the amount of T cells in MLN, and cytokine secretion of MLN lymphocytes.

Conclusions

In conclusion, feeding obese rats a diet with regular fat content but variable fat sources for 10 weeks, changed the fatty acid composition of MAT but not its secretory properties or MLN functions. Although the local immune system was not influenced, lard-feeding induced minor changes in systemic immune function.     

Protective effects of garlic extract on cardiac function,heart rate variability,and cardiac mitochondria in obese insulin-resistant rats

Purpose

Garlic has been shown to exhibit antioxidant effects and cardioprotective properties. However, the effects of garlic extract on the heart in insulin resistance induced by long-term high-fat-diet consumption are not well defined. Therefore, we sought to determine the effects of garlic extract in the obese insulin-resistant rats.

Methods

Male Wistar rats (180–200 g) were divided into two groups: normal-diet or high-fat-diet (n = 24/group) fed for 12 weeks. Rats in each groups were divided into three subgroups (n = 8 each): vehicle or garlic extract (250 or 500 mg/kg/day, respectively) treated for 28 days. At the end of the treatment, the metabolic parameters, heart rate variability (HRV), cardiac function, and cardiac mitochondrial function were determined.

Results

Rats that received a high-fat-diet for 12 weeks had increased body weight, visceral fat, plasma insulin levels, total cholesterol, oxidative stress levels, depressed HRV, and cardiac mitochondrial dysfunction. Garlic extract at both concentrations significantly decreased the plasma insulin, total cholesterol, homeostasis model assessment index, and oxidative stress levels. Furthermore, garlic extract at both doses restored the HRV, cardiac function, and cardiac mitochondrial function.

Conclusion

We concluded that garlic extract at both concentrations exerted cardioprotective effects against cardiac dysfunction and mitochondrial dysfunction in obese insulin-resistant rats.     

Three-month B vitamin supplementation in pre-school children affects folate status and homocysteine,but not cognitive performance

Background

Suboptimal vitamin B status might affect cognitive performance in early childhood. We tested the hypothesis that short-term supplementation with folic acid and selected B vitamins improves cognitive function in healthy children in a population with relatively low folate status.

Methods

We screened 1,002 kindergarten children for suboptimal folate status by assessing the total urinary para-aminobenzoylglutamate excretion. Two hundred and fifty low ranking subjects were recruited into a double blind, randomized, controlled trial to receive daily a sachet containing 220 μg folic acid, 1.1 mg vitamin B₂, 0.73 mg B₆, 1.2 μg B₁₂ and 130 mg calcium, or calcium only for 3 months. Primary outcomes were changes in verbal IQ, short-term memory and processing speed between baseline and study end. Secondary outcomes were urinary markers of folate and vitamin B₁₂ status, acetyl-para-aminobenzoylglutamate and methylmalonic acid, respectively, and, in a subgroup of 120 participants, blood folate and plasma homocysteine.

Results

Pre- and post-intervention cognitive measurements were completed by 115 children in the intervention and 122 in the control group. Compared to control, median blood folate increased by about 50 % (P for difference, P < 0.0001). Homocysteine decreased by 1.1 μmol/L compared to baseline, no change was seen in the control group (P for difference P < 0.0001) and acetyl-para-aminobenzoylglutamate was 4 nmol/mmol higher compared to control at the end of the intervention (P < 0.0001). We found no relevant differences between the groups for the cognitive measures.

Conclusion

Short-term improvement of folate and homocysteine status in healthy children does not appear to affect cognitive performance.     

Breast milk fatty acid composition differs between overweight and normal weight women: the STEPS Study

Objective

We studied differences in breast milk fatty acid (FA) composition between overweight and normal weight women and the effect of FA composition on children’s cholesterol concentrations at 13 months and growth from birth to 13 months.

Methods

Samples were collected from lactating women (n = 100) participating in STEPS study at infant’s age of 3 months, and FA composition was analyzed with gas chromatography. Diet of mother was studied with Index of Diet Quality at third trimester of pregnancy and with food frequency questionnaire on sampling day. The children’s weights and heights were collected from hospital records at birth and during study visits at 13 months.

Results

Overweight women’s breast milk compared to normal weight women’s breast milk contained higher amount of saturated FAs (46.3 vs. 43.6 %, P = 0.012), lower amount of n-3FAs (2.2 vs. 2.7 %, P = 0.010), lower ratio of unsaturated to saturated FAs (1.1 vs. 1.3, P = 0.008), and higher ratio of n-6 to n-3 FAs (5.7 vs. 4.9, P = 0.031) than those of normal weight women even after adjusting for maternal diet (P < 0.05 for all). Normal weight women adhered more to dietary recommendations during pregnancy, whereas no differences were found in diet at sampling 3 months postpartum. The children’s weight gains correlated with saturated FAs (R = 0.22, P = 0.04) and the ratio of unsaturated to saturated FAs (R = ?0.23, P = 0.038) in milk; however, effects diminished after adjusting for total duration of breastfeeding. Milk FA composition was not associated with children’s cholesterol concentrations at 13 months.

Conclusions

Breast milk FA composition differed between overweight and normal weight women.