Bureau of Nutritional science

Ottawa, Canada

Bureau of Nutritional science

Ottawa, Canada

Time filter

Source Type

Bhatia J.,American Academy of Pediatrics | Courant G.,Breastfeeding Committee for Canada | Davidson A.G.F.,Human Milk Banking Association | McCrea J.,Health Canada | Underhill L.,Bureau of Nutritional science
Paediatrics and Child Health (Canada) | Year: 2012

As more is learned about the importance of the intestinal microbiome to human health there is increasing interest in the potential benefits of probiotics. Probiotics are live micro-organisms which, when consumed in adequate amounts, confer a health effect on the host by altering its microflora. Probiotics have been administered both prophylactically and therapeutically for various conditions. This statement definines the development and role of intestinal microflora, and examines the evidence supporting the use of different probiotics to treat common paediatric conditions, such as diarrhea, atopy, functional intestinal disorders and necrotizing enterocolitis. Recommendations to guide physicians in the judicious use of these products are offered. © Canadian Paediatric Society 2012.


Price W.D.,12818 Wolfsville Road | Underhill L.,Bureau of Nutritional science
Journal of Agricultural and Food Chemistry | Year: 2013

With the development of recombinant DNA techniques for genetically modifying plants to exhibit beneficial traits, laws and regulations were adopted to ensure the safety of food and feed derived from such plants. This paper focuses on the regulation of genetically modified (GM) plants in Canada and the United States, with emphasis on the results of the compositional analysis routinely utilized as an indicator of possible unintended effects resulting from genetic modification. This work discusses the mandate of Health Canada and the Canadian Food Inspection Agency as well as the U.S. Food and Drug Administration's approach to regulating food and feed derived from GM plants. This work also addresses how publications by the Organisation for Economic Co-operation and Development and Codex Alimentarius fit, particularly with defining the importance and purpose of compositional analysis. The importance of study design, selection of comparators, use of literature, and commercial variety reference values is also discussed. © 2013 American Chemical Society.


Shastri P.,University of Ontario Institute of Technology | McCarville J.,University of Ontario Institute of Technology | Kalmokoff M.,Agriculture and Agri Food Canada | Brooks S.P.J.,Bureau of Nutritional science | Green-Johnson J.M.,University of Ontario Institute of Technology
Biology of Sex Differences | Year: 2015

Abstract Background: Mechanistic data to support health claims is often generated using rodent models, and the influence of prebiotic supplementation has largely been evaluated using male rodents. Given that sex-based differences in immune parameters are well recognized and recent evidence suggests differences in microbiota composition between sexes, validation of the effectiveness of prebiotics merits assessment in both males and females. Here, we have compared the effect of oligofructose (OF) supplementation on the fecal bacterial community, short chain fatty acid profiles, and gut mucosal and systemic immune parameters in male and female rats. Methods: Male and female rats were fed rodent chow or chow supplemented with OF (5 % w/w). Fecal community change was examined by analyzing 16S rRNA gene content. To compare effects of OF between sexes at the gut microbial and mucosal immune level, fecal short chain fatty acid and tissue cytokine profiles were measured. Serum lipopolysaccharide levels were also evaluated by the limulus amebocyte lysate assay as an indirect means of determining gut permeability between sexes. Results: In the fecal community of females, OF supplementation altered community structure by increasing abundance in the Phylum Bacteroidetes. In male rats, no changes in fecal community structure were observed, although fecal butyrate levels significantly increased. Liver Immunoglobulin A (IgA) levels were higher in males relative to females fed OF, and serum LPS concentrations were higher in males independent of diet. Females had higher basal levels of the regulatory cytokine interleukin-10 (IL-10) in the colon and liver, while males had higher basal levels of the pro-inflammatory cytokines IL-6 and cytokine-induced neutrophil chemoattractant-1 (CINC-1) in the cecum and liver. Conclusions: We have shown that male and female rat gut communities metabolize an OF-supplemented diet differently. Sex-specific responses in both the fecal community and systemic immune parameters suggest that this difference may result from an increase in the availability of gut peptidyl-nitrogen in the males. These findings demonstrate the importance of performing sex-comparative studies when investigating potential health effects of prebiotics using rodent models. © 2015 Shastri et al.


Wei S.Q.,University of Montréal | Audibert F.,University of Montréal | Hidiroglou N.,Bureau of Nutritional science | Sarafin K.,Bureau of Nutritional science | And 4 more authors.
BJOG: An International Journal of Obstetrics and Gynaecology | Year: 2012

Objective Whether vitamin D deficiency in pregnancy is a cause of pre-eclampsia remains controversial. Most previous studies to date have assessed exposure at only one time-point in pregnancy. We assessed longitudinal vitamin D status during pregnancy and the risk of pre-eclampsia. Design Prospective cohort study. Setting Seventeen urban obstetric hospitals, Canada. Population Pregnant women who were participants in a trial of vitamin C and E supplementation for the prevention of pre-eclampsia. Canadian participants who consented to participate in a biobank with plasma specimens available at the baseline visit were included (n = 697). Methods Maternal plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured at 12-18 and 24-26 weeks of gestation using chemiluminescence immunoassay. Main outcome measures Pre-eclampsia. Results Of the women, 39% were vitamin D deficient (25(OH)D <50 nmol/l). A strong positive correlation was observed in maternal 25(OH)D concentrations between the two gestational age windows (r = 0.69, P < 0.0001). Mean maternal 25(OH)D concentrations at 24-26 weeks of gestation were significantly lower in women who subsequently developed pre-eclampsia compared with those who did not (mean ± SD: 48.9 ± 16.8 versus 57.0 ± 19.1 nmol/l, P = 0.03). Women with 25(OH)D < 50 nmol/l at 24-26 weeks gestation experienced an increased risk of pre-eclampsia (adjusted odds ratio 3.24, 95% confidence interval 1.37-7.69), whereas the association was not statistically significant for maternal 25(OH)D level at 12-18 weeks of gestation. Conclusions Lower maternal 25(OH)D levels at late mid-trimester were associated with an increased risk of pre-eclampsia. © 2012 RCOG.


Sarafin K.,Bureau of Nutritional science | Durazo-Arvizu R.,Loyola University Chicago | Tian L.,Stanford University | Phinney K.W.,U.S. National Institute of Standards and Technology | And 6 more authors.
American Journal of Clinical Nutrition | Year: 2015

Background: The Canadian Health Measures Survey (CHMS) is an ongoing cross-sectional national survey that includes a measure of 25-hydroxyVitamin D [25(OH)D] by immunoassay. For cycles 1 and 2, the collection period occurred approximately every 2 y, with a new sample of w5600 individuals. Objective: The goal was to standardize the original 25(OH)D CHMS values in cycles 1 and 2 to the internationally recognized reference measurement procedures (RMPs) developed by the US National Institute for Standards and Technology (NIST) and Ghent University, Belgium. Design: Standardization was accomplished by using a 2-step procedure. First, serum samples corresponding to the original plasma samples were remeasured by using the currently available immunoassay method. Second, 50 serum samples with known 25(OH)D values assigned by the NIST and Ghent reference method laboratories were measured by using the currently available immunoassay method. The mathematical models for each step-i.e., 1) YCurrent = XOriginal and 2) YNIST-Ghent = XCurrent -were estimated by using Deming regression, and the 2 models were solved to obtain a single equation for converting the "original" values to NIST-Ghent RMP values. Results: After standardization (cycles 1 and 2 combined), the percentage of Canadians with 25(OH)D values <40 nmol/L increased from 16.4% (original) to 19.4% (standardized), and values <50 nmol/L increased from 29.0% (original) to 36.8% (standardized). The 25(OH)D standardized distributions (cycles 1 and 2 analyzed separately) were similar across age and sex groups; slightly higher values were associated with cycle 2 in the young and old. This finding contrasts with the original data, which indicated that cycle 2 values were lower for all age groups. Conclusion: The shifts in 25(OH)D distribution brought about by standardization indicate its importance in drawing correct conclusions about potential population deficiencies and insufficiencies and in permitting the comparison of distributions between national surveys. © 2015 American Society for Nutrition.


Berger C.,McGill University | Greene-Finestone L.S.,Public Health Agency of Canada | Langsetmo L.,McGill University | Kreiger N.,McGill University | And 12 more authors.
Journal of Bone and Mineral Research | Year: 2012

Vitamin D is essential for facilitating calcium absorption and preventing increases in parathyroid hormone (PTH), which can augment bone resorption. Our objectives were to examine serum levels of 25-hydroxyvitamin D [25(OH)D] and PTH, and factors related to longitudinal change in a population-based cohort. This is the first longitudinal population-based study looking at PTH and 25(OH)D levels. We analyzed 3896 blood samples from 1896 women and 829 men in the Canadian Multicentre Osteoporosis Study over a 10-year period starting in 1995 to 1997. We fit hierarchical models with all available data and adjusted for season. Over 10 years, vitamin D supplement intake increased by 317 (95% confidence interval [CI] 277 to 359) IU/day in women and by 193 (135 to 252) IU/day in men. Serum 25(OH)D (without adjustment) increased by 9.3 (7.3 to 11.4) nmol/L in women and by 3.5 (0.6 to 6.4) nmol/L in men but increased by 4.7 (2.4 to 7.0) nmol/L in women and by 2.7 (-0.6 to 6.2) nmol/L in men after adjustment for vitamin D supplements. The percentage of participants with 25(OH)D levels <50 nmol/L was 29.7% (26.2 to 33.2) at baseline and 19.8% (18.0 to 21.6) at year 10 follow-up. PTH decreased over 10 years by 7.9 (5.4 to 11.3) pg/mL in women and by 4.6 (0.2 to 9.0) pg/mL in men. Higher 25(OH)D levels were associated with summer, younger age, lower body mass index (BMI), regular physical activity, sun exposure, and higher total calcium intake. Lower PTH levels were associated with younger age and higher 25(OH)D levels in both women and men and with lower BMI and participation in regular physical activity in women only. We have observed concurrent increasing 25(OH)D levels and decreasing PTH levels over 10 years. Secular increases in supplemental vitamin D intake influenced both changes in serum 25(OH)D and PTH levels. Copyright © 2012 American Society for Bone and Mineral Research.


Fernandez L.,Bureau of Nutritional science | Jee P.,Bureau of Nutritional science | Klein M.-J.,Bureau of Nutritional science | Fischer P.,Bureau of Nutritional science | And 3 more authors.
Clinical Biochemistry | Year: 2013

Objectives: There are no direct comparisons of blood glucose values in samples collected with barrier serum tubes (SST™) and NaF/potassium oxalate (NaF/KOx) plasma tubes. Collection of samples in SST™ tubes can offer considerable savings and specimen processing advantages for national level surveys. Design and methods: Serum and plasma samples were collected under 'field conditions' from a single draw of 3692 individuals participating in the Canadian Health Measures Survey. The samples were analyzed retrospectively using the VITROS GLU Slide method (glucose oxidase-based). Results: There was a high rate of hemolysis in the NaF/KOx tubes (86.2%) while hemolysis was infrequently observed with the SST™ tubes (2%). Comparing only blood draws where no hemolysis was observed in both tubes (n. =. 495; paired t-test) showed no effect of tube type on serum/plasma glucose concentrations. This was also observed when data was restricted to cases when only SST™ samples were not hemolyzed (n. =. 3546; paired t-test). Conclusions: These data show that both collection tubes can be used under survey collection and processing conditions to measure glucose with our assay system with no difference in reported results. © 2012.


Poon R.,Environmental Health Science Research Bureau | Valli V.E.,VDx Veterinary Diagnostics | Nimal Ratnayake W.M.,Bureau of Nutritional science | Rigden M.,Environmental Health Science Research Bureau | Pelletier G.,Environmental Health Science Research Bureau
Journal of Applied Toxicology | Year: 2013

Jatropha oil is an emerging feedstock for the production of biodiesels. The increasing use of this nonedible, toxic oil will result in higher potential for accidental exposures. A repeated-dose 28-day oral toxicity study was conducted to provide data for risk assessment. Jatropha oil diluted in corn oil was administered by gavage to male and female rats at 0.5, 5, 50 and 500mgkg-1 body weight per day for 28 consecutive days. Control rats were administered corn oil only. The growth rates and consumption of food and water were monitored. At necropsy, organs were weighed and hematological parameters assessed. Serum clinical chemistry and C-reactive protein were measured and histological examinations of organs and tissues were performed. Markedly depressed growth rate was observed in males and females receiving Jatropha oil at 500mgkg-1 per day. Decreased white blood cell and lymphocyte counts were detected in females at 50 and 500mgkg-1 per day and in males at 500mgkg-1 per day. These changes were correlated to mild and reversible histological changes in male and female spleens. In the liver, a mild increase in portal hepatocytes cytoplasm density was observed in males and females, while periportal vacuolation was observed exclusively in females. Mild acinar proliferation was observed in the female mammary glands at all dose levels. It is concluded that Jatropha oil produces adverse effects on female rats starting at 50mgkg-1 per day with decreased white blood cell and lymphocyte counts and at 500mgkg-1 per day in both genders in term of depressed growth rates. © 2011 John Wiley & Sons, Ltd.


Tamber S.,Bureau of Microbial Hazards | Swist E.,Bureau of Nutritional science | Oudit D.,Bureau of Microbial Hazards
Journal of Food Protection | Year: 2016

Despite the increasing popularity of sprouted chia and flax seed powders, no data have been reported on their intrinsic physicochemical properties and background microflora. Here, we report the moisture content, water activity, pH, and fatty acid methyl ester and bacteriological profiles of 19 sprouted chia and flax seed samples, 10 of which were associated with an outbreak of salmonellosis in Canada and the United States. The physicochemical parameters of the Salmonella-positive samples did not differ significantly from those of the negative samples. However, the higher Enterobacteriaceae and coliform levels on the contaminated powders were associated with the presence of Salmonella. Enumeration of Salmonella by the most probable number (MPN) method revealed concentrations ranging from 1 MPN per 3 g of powder to 1 MPN per 556 g of powder. The results of this study demonstrate that low numbers of Salmonella may be linked to foodborne outbreaks.


PubMed | Fred Hutchinson Cancer Research Center, Boston College, Iowa State University, University of Ottawa and 10 more.
Type: Review | Journal: The American journal of clinical nutrition | Year: 2016

Dietary Reference Intakes (DRIs) are used in Canada and the United States in planning and assessing diets of apparently healthy individuals and population groups. The approaches used to establish DRIs on the basis of classical nutrient deficiencies and/or toxicities have worked well. However, it has proved to be more challenging to base DRI values on chronic disease endpoints; deviations from the traditional framework were often required, and in some cases, DRI values were not established for intakes that affected chronic disease outcomes despite evidence that supported a relation. The increasing proportions of elderly citizens, the growing prevalence of chronic diseases, and the persistently high prevalence of overweight and obesity, which predispose to chronic disease, highlight the importance of understanding the impact of nutrition on chronic disease prevention and control. A multidisciplinary working group sponsored by the Canadian and US government DRI steering committees met from November 2014 to April 2016 to identify options for addressing key scientific challenges encountered in the use of chronic disease endpoints to establish reference values. The working group focused on 3 key questions: 1) What are the important evidentiary challenges for selecting and using chronic disease endpoints in future DRI reviews, 2) what intake-response models can future DRI committees consider when using chronic disease endpoints, and 3) what are the arguments for and against continuing to include chronic disease endpoints in future DRI reviews? This report outlines the range of options identified by the working group for answering these key questions, as well as the strengths and weaknesses of each option.

Loading Bureau of Nutritional science collaborators
Loading Bureau of Nutritional science collaborators