Dietary supplementation with soy isoflavones or replacement with soy proteins prevents hepatic lipid droplet accumulation and alters expression of genes involved in lipid metabolism in rats.

Accumulation of hepatic lipid droplet (HLD) is the hallmark pathology of non-alcoholic fatty liver disease (NAFLD). This study examined the effects of soy isoflavones (ISF) and different amounts of soy proteins on the accumulation of HLD, lipid metabolism and related gene expression in rats. Weanling Sprague-Dawley rats were fed diets containing either 20 % casein protein without (D1) or with (D2) supplemental ISF (50 mg/kg diet) or substitution of casein with increasing amounts of alcohol-washed soy protein isolate (SPI, 5, 10, and 20 %; D3, D4, D5) for 90 days.

Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality.

Dietary antinutritional factors have been reported to adversely affect the digestibility of protein, bioavailability of amino acids and protein quality of foods. Published data on these negative effects of major dietary antinutritional factors are summarized in this manuscript. Digestibility and the quality of mixed diets in developing countries are considerably lower than of those in developed regions.

High-dose supplemental selenite to male Syrian hamsters fed hypercholesterolaemic diets alters Ldlr, Abcg8 and Npc1l1 mRNA expression and lowers plasma cholesterol concentrations.

The aim of the present study was to elucidate possible cholesterol-lowering mechanism(s) of high-dose supplemental Se in the form of selenite, a known hypocholesterolaemic agent. Male Syrian hamsters (four groups, ten per group) were fed semi-purified diets for 4 weeks containing 0.1 % cholesterol and 15 % saturated fat with selenite corresponding to varying levels of Se: (1) Se 0.

Canadians continue to consume too much sodium and not enough potassium.

Objectives: Excessive sodium (Na) intakes and insufficient potassium (K) intakes are known contributors to hypertension. In July 2010, the Health Canada-led multi-stakeholder Sodium Working Group issued recommendations to lower Na intakes of Canadians. Baseline data and ongoing monitoring are needed.

Evidence of oxidative stress in relation to feeding type during early life in premature infants.

Morbidity in the premature (PT) infant may reflect difficult adaptation to oxygen. We hypothesized that feeding including formula feeding (F) and feeding mother's milk (HM) with added fortifier would affect redox status. Therefore, 65 PT infants (birth weight: 1146 ± 261 g; GA: 29 ± 2.

Determination of total iodine in food samples using inductively coupled plasma-mass spectrometry.

A method was developed and validated for the extraction and determination of total iodine (I) in food composite samples, representing different foods available on the Canadian market, by inductively coupled plasma-mass spectrometry (ICP-MS). Prior to analysis, samples were digested in a closed microwave system using a mixture of nitric acid and perchloric acid. The detection limit for iodine determination was 29 nglg and precisions of 10 and 1.

Antioxidant Supplements Improve Profiles of Hepatic Oxysterols and Plasma Lipids in Butter-fed Hamsters.

Hypercholesterolemic diets are associated with oxidative stress that may contribute to hypercholesterolemia by adversely affecting enzymatically-generated oxysterols involved in cholesterol homeostasis. An experiment was conducted to examine whether the cholesterol-lowering effects of the antioxidants selenium and α-tocopherol were related to hepatic oxysterol concentrations. Four groups of male Syrian hamsters (n = 7-8) were fed high cholesterol and saturated fat (0.

Effect of calcium on iron absorption in women with marginal iron status.

We measured non-haem Fe absorption with and without added Ca in a short-term feeding study, in thirteen women with marginal Fe status, by the use of a double stable isotope technique. Supplementing 500 mg Ca as calcium carbonate significantly (P = 0.0009) reduced Fe absorption from a single meal from 10.

Application of the Dietary Reference Intakes in developing a recommendation for pregnancy iron supplements in Canada.

Background: For many pregnant Canadian women, usual iron intakes from food appear to be inadequate compared with Dietary Reference Intake requirement estimates.

Objective: Dietary intake modeling was undertaken to determine an amount of iron supplementation that would confer acceptably low prevalence of apparently inadequate and apparently excessive intakes.

Design: The distribution of usual dietary iron intakes was estimated with the use of 24-h recalls from pregnant women aged 19-50 y in the Canadian Community Health Survey, Cycle 2.

Regulatory frameworks for copper considering chronic exposures of the population.

Copper is an essential nutrient that is toxic in excess. Copper intakes from a balanced diet appear to meet the needs of most healthy individuals, because overt deficiency and toxicity are rare. Some uncertainty, however, persists because of limitations in currently available biomarkers used to assess copper status and the paucity of data available to establish tolerable upper levels of intake.

Impact of dietary protein on lipid metabolism in hamsters is source-dependent and associated with changes in hepatic gene expression.

This study tested the hypothesis that protein source is a factor determining the impact of the diet on lipid metabolism in hamsters. Twenty-eight hamsters of similar body weight were assigned for a period of 8 weeks to one of the following four diets (seven per group) containing either 20 % (w/w) casein (CAS), beef protein (BF), wheat gluten (WG) or soya protein (SOY). The fat composition of the diet was the same (15.

An overview of methods for assessment of iron bioavailability from foods nutritionally enhanced through biotechnology.

Iron deficiency and iron deficiency anemia continue to be significant public health problems worldwide. While supplementation and fortification have been viable means to improve iron nutriture of the population in developed countries, they may be less successful in developing regions for a number of reasons, including complexities in distribution and consumer compliance. Biofortification of staple crops, through conventional plant breeding strategies or modern methods of biotechnology, provides an alternative approach that may be more sustainable once initial investments have been made.

Sparing effects of selenium and ascorbic acid on vitamin C and E in guinea pig tissues.

Background: Selenium (Se), vitamin C and vitamin E function as antioxidants within the body. In this study, we investigated the effects of reduced dietary Se and L-ascorbic acid (AA) on vitamin C and alpha-tocopherol (AT) status in guinea pig tissues.

Methods: Male Hartley guinea pigs were orally dosed with a marginal amount of AA and fed a diet deficient (Se-D/MC), marginal (Se-M/MC) or normal (Se-N/MC) in Se.

The iron status of Canadian adolescents and adults: current knowledge and practical implications.

Overview: Iron is an essential nutrient, playing a central role in oxygen transport and cellular energy metabolism. The importance of ensuring adequate bioavailable dietary iron stems from the severe consequences associated with iron deficiency (ID) and anemia, including reduced immune function and resistance to infection, developmental delays and irreversible cognitive deficits in young children, impaired physical work performance, and adverse pregnancy outcomes.

Specific Populations: Poor dietary iron intake and ID exist in Canada, particularly in women of reproductive age.

Limited effects of combined dietary copper deficiency/iron overload on oxidative stress parameters in rat liver and plasma.

Copper (Cu) deficiency decreases the activity of Cu-dependent antioxidant enzymes such as Cu,zinc-superoxide dismutase (Cu,Zn-SOD) and may be associated with increased susceptibility to oxidative stress. Iron (Fe) overload represents a dietary oxidative stress relevant to overuse of Fe-containing supplements and to hereditary hemochromatosis. In a study to investigate oxidative stress interactions of dietary Cu deficiency with Fe overload, weanling male Long-Evans rats were fed one of four sucrose-based modified AIN-93G diets formulated to differ in Cu (adequate 6 mg/kg diet vs.

Effects of antinutritional factors on protein digestibility and amino acid availability in foods.

Digestibility of protein in traditional diets from developing countries such as India, Guatemala, and Brazil is considerably lower compared to that of protein in typical North American diets (54-78 versus 88-94%). The presence of less digestible protein fractions, high levels of insoluble fiber, and high concentrations of antinutritional factors in the diets of developing countries, which are based on less refined cereals and grain legumes as major sources of protein, are responsible for poor digestibility of protein. The effects of the presence of some of the important antinutritional factors on protein and amino digestibilities of food and feed products are reviewed in this chapter.

Soy protein isolate increases hepatic thyroid hormone receptor content and inhibits its binding to target genes in rats.

Our previous studies showed that intake of 20% alcohol-washed soy protein isolate (SPI) significantly increased hepatic thyroid hormone receptor (TR) beta1 protein content in rats. However, whether SPI influences the binding ability of TR to its target genes is unknown. The purpose of this study was to examine the effect of increasing amounts of dietary SPI on hepatic TRbeta1 content and the binding of TR to thyroid hormone response element (TRE) in rats.

Manganese content of soy or rice beverages is high in comparison to infant formulas.

Objective: Well-meaning but inadequately informed parents may perceive plant-based beverages such as soy beverages (SB) or rice beverages (RB) as an alternative to infant formula. Manganese (Mn) is an essential mineral nutrient found at high levels in plants such as soy and rice. Excessive Mn exposure increases the risk of adverse neurological effects.

Nephrocalcinosis caused by dietary calcium:phosphorus imbalance in female rats develops rapidly and is irreversible.

Female rats fed the standardized AIN-76A diet develop kidney calcium deposits (nephrocalcinosis, NC). A low dietary Ca:P molar ratio is a primary factor in this disorder. The AIN-93G diet has a lower P content and higher Ca:P molar ratio and lowers the incidence of NC.

Micronutrient supplementation: when is best and why?

For many nutrients, a systematic determination of the effects of high intakes over extended periods of time has not been conducted. Governments and scientific bodies have just begun to establish the methodology for, and to conduct, nutrient risk assessments for setting 'tolerable upper levels of intake' (UL) for nutrients. Nutrient risk assessment provides the framework for using available information to evaluate the safety of nutrients when added to foods or when consumed as supplements, in order to minimize the risks from over-consumption.

The carbonyl content of specific plasma proteins is decreased by dietary copper deficiency in rats.

Copper (Cu) deficiency is associated with increased susceptibility of tissue homogenates or lipoproteins to oxidation in vitro. Plasma is easily sampled and contains both lipid and protein components that may be susceptible to oxidation, making it appropriate to investigate plasma oxidation variables as biomarkers of in vivo oxidative stress. Oxidation of plasma proteins may be discernible as an increased content of carbonyl (aldehyde or ketone) groups on the proteins.

The concentrations and ratio of dietary calcium and phosphorus influence development of nephrocalcinosis in female rats.

Nephrocalcinosis (NC) in female rats can complicate the interpretation of nutritional or toxicological studies involving the kidney. Recent reformulations of standardized rodent diets such as AIN-93G and NTP-2000 sought to optimize the dietary Ca:P ratio, an important etiologic factor in NC. The effect of increasing intakes of Ca and P together at their optimal molar ratio has not been systematically studied.