Reproducibility and validity of the Toronto-modified Harvard food frequency questionnaire in a multi-ethnic sample of young adults.

Background/objectives: To assess the reproducibility and validity of a Toronto-modified Harvard food frequency questionnaire (FFQ) among a multi-ethnic sample of young adults.

Subjects/methods: A total of 150 participants recruited from the Toronto Nutrigenomics and Health Study cohort who had existing dietary intakes assessed by FFQ (FFQ1) and reassessment one year later (FFQ2). Of these, 100 participants also completed a three-day food record to evaluate the validity of the FFQ for 38 nutrients (energy, 14 macronutrients, 22 micronutrients, and 1 bioactive).

Genetic variation in the vitamin D receptor, plasma 25-hydroxyvitamin D, and biomarkers of cardiometabolic disease in Caucasian young adults.

Background/aims: Vitamin D regulates gene transcription by binding to the vitamin D receptor (VDR), potentially affecting cardiometabolic disease risk. However, studies of 25-hydroxyvitamin D [25(OH)D] and cardiometabolic disease are inconsistent. Inconsistencies may result from unaccounted for interactions between VDR genetic variants and 25(OH)D.

Plasma vitamin D and biomarkers of cardiometabolic disease risk in adult Canadians, 2007-2009.

Introduction: Vitamin D may modulate cardiometabolic disease risk, although the relationship has not been investigated in the general Canadian population. Understanding this relationship may inform public health strategies to curb the incidence of cardiometabolic disease in Canada and elsewhere. The objectives of this study were to examine the association between vitamin D and traditional and novel biomarkers of cardiometabolic disease and to describe the extent of the month-to-month fluctuations of vitamin D in the Canadian population.

Plasma 25-hydroxyvitamin D, hormonal contraceptive use, and the plasma proteome in Caucasian, East Asian, and South Asian young adults.

Vitamin D affects gene expression, but its downstream effects on the proteome are unclear. Hormonal contraceptives (HC), which affect vitamin D metabolism and have widespread effects on the plasma proteome, may confound the association between vitamin D and the proteome. We determined whether HC use modified the association between 25-hydroxyvitamin D (25D) and a panel of 54 high-abundance plasma proteins.

Association between the plasma proteome and plasma α-tocopherol concentrations in humans.

Vitamin E is a lipophilic antioxidant that has been inversely associated with certain chronic diseases; however, the biological processes regulated by this vitamin have not been fully elucidated. The objective of the present study was to examine the association between the most biologically active and abundant form of vitamin E in the circulation, α-tocopherol, and the plasma proteome. Subjects were from the Toronto Nutrigenomics and Health Study and included men and women (n=1,022) who completed a general health and lifestyle questionnaire and 196-item food frequency questionnaire, and provided a fasting blood sample.

The association between obesity, cardiometabolic disease biomarkers, and innate immunity-related inflammation in Canadian adults.

Introduction: Obesity is associated with a state of chronic inflammation, and increased cardiometabolic disease risk. The present study examined the relationship between body mass index (BMI) and cardiometabolic and inflammatory biomarkers among normal weight, overweight, and obese Canadian adults.

Methods: Subjects (n = 1805, aged 18 to 79 years) from the Canadian Health Measures Survey (CHMS) were examined for associations between BMI, cardiometabolic markers (apolipoprotein [Apo] A1, ApoB, low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], total cholesterol, total cholesterol/HDL ratio [total:HDL-C ratio], triglycerides, and glycosylated hemoglobin [HbA(1c)]), inflammatory factors (C-reactive protein [CRP], fibrinogen, and homocysteine), and 25-hydroxyvitamin D [25(OH)D].

Glutathione S-transferase (GST) M1, but not GSTT1, genotype influences plasma proteomic profiles in Caucasian and East Asian young adults.

Glutathione S-transferase (GST) M1 and T1 are major detoxifying enzymes that have been associated with a number of chronic diseases, but their effect on various physiological pathways remains unclear. We investigated the association between the common GSTM1 and GSTT1 genotypes and multiple disease-related high-abundance proteins of the plasma proteome in young Caucasian (n = 476) and East Asian (n = 352) adults. Overnight fasting blood samples were collected, and 54 high-abundance plasma proteins from several physiological pathways were quantified by mass spectrometry-based multiple reaction monitoring (LC-MRM/MS).

Associations between polymorphisms in the AHR and CYP1A1-CYP1A2 gene regions and habitual caffeine consumption.

Background: Recent genome-wide association studies (GWASs) from populations of European descent identified single nucleotide polymorphisms (SNPs) in aryl-hydrocarbon receptor (AHR) and cytochrome P450 1A1 and 1A2 (CYP1A1-CYP1A2) genes that are associated with habitual caffeine and coffee consumption.

Objective: We examined whether these SNPs (AHR: rs6968865 and rs4410790; CYP1A1-CYP1A2: rs2472297 and rs2470893) and 6 additional tag SNPs in the AHR gene were associated with habitual caffeine consumption in a Costa Rican population.

Design: Subjects were from a case-control study of gene-diet interactions and myocardial infarction.

Association between the plasma proteome and serum ascorbic acid concentrations in humans.

Vitamin C has been associated with a reduced risk of chronic diseases, but the biological pathways regulated by vitamin C are not all known. The objective was to use a proteomics approach to identify plasma proteins associated with circulating levels of ascorbic acid. Men and women (n=1022) 20-29 years of age from the Toronto Nutrigenomics and Health Study completed a general health and lifestyle questionnaire and a 196-item food frequency questionnaire and provided a fasting blood sample.

Genetic determinants of dietary antioxidant status.

Oxidative stress refers to a physiological state in which an imbalance between pro-oxidants and antioxidants results in oxidative damage. Oxidative stress has been associated with the development of numerous chronic diseases such as type 2 diabetes, cardiovascular disease (CVD), osteoporosis, and cancer. Endogenous production of free radicals occurs during normal physiological processes, such as aerobic metabolism, oxidation of biological molecules, and enzymatic activity.

Nutrigenetics and modulation of oxidative stress.

Oxidative stress develops as a result of an imbalance between the production and accumulation of reactive species and the body's ability to manage them using exogenous and endogenous antioxidants. Exogenous antioxidants obtained from the diet, including vitamin C, vitamin E, and carotenoids, have important roles in preventing and reducing oxidative stress. Individual genetic variation affecting proteins involved in the uptake, utilization and metabolism of these antioxidants may alter their serum levels, exposure to target cells and subsequent contribution to the extent of oxidative stress.

Fifty years of memory of college grades: accuracy and distortions.

One to 54 years after graduating, 276 alumni correctly recalled 3,025 of 3,967 college grades. Omission errors increased with the retention interval, and better students made fewer errors. Accuracy of recall increased with confidence in recall.