Ready-to-eat cereal consumption is associated with improved nutrient intakes and diet quality in Canadian adults and children across income levels.

Background: Results from observational studies suggest ready-to-eat cereal (RTEC) consumption is associated with higher diet quality. In the United States, studies have shown that RTEC is an important contributor to nutrient intakes across income levels. However, it is unknown if this association varies by income level in the Canadian population.

Ascorbic acid is associated with favourable hormonal profiles among infertile males.

Introduction: Infertility affects about 16% of North American couples, with the male factor contributing to ∼30% of cases. Reproductive hormones play an integral role in regulating the reproductive system and consequently, fertility. Oxidative stress reduces testosterone synthesis, and reduction in oxidative stress can improve hormone profiles.

Plasma Carotenoids and Premenstrual Symptoms in a Multi-Ethnic Population of Young Women.

Premenstrual symptoms are experienced by most women of reproductive age, but effective therapies are limited. Carotenoids may have an attenuating effect on premenstrual symptoms; however, studies to date are equivocal. The objective of the present study was to examine the association between plasma concentrations of seven carotenoids and premenstrual symptom severity in 553 women from the Toronto Nutrigenomics and Health study.

Variation in the vitamin D receptor gene, plasma 25-hydroxyvitamin D, and risk of premenstrual symptoms.

Background: Vitamin D status has been associated with the presence and severity of several premenstrual symptoms (PMSx) in some, but not all studies. Inconsistencies among findings may be explained by unaccounted genetic variation in the vitamin D receptor (VDR).

Objective: To determine whether associations between vitamin D status and individual PMSx are influenced by VDR genotype.

CYP1A2 Genotype Modifies the Effects of Caffeine Compared With Placebo on Muscle Strength in Competitive Male Athletes.

Caffeine is commonly used to improve athletic performance across a variety of sports. Previously, the CYP1A2 gene has been shown to modify the effects of caffeine on endurance performance. The effect of caffeine on strength and power activities is unclear and may differ depending on an individual's CYP1A2 genotype.

Recent advances and current controversies in genetic testing for personalized nutrition.

Purpose Of Review: Considerable interest in personalized nutrition exists among the general public, policymakers, healthcare organizations and the private sector, but there is also skepticism of its utility. The present review aims to provide a summary of current controversies in the field of nutrigenomics, and to highlight recent research on the potential impact of implementing genetic testing for personalized nutrition in practice.

Recent Findings: Numerous companies already offer genetic testing for personalized nutrition based on research developments in nutritional genomics.

Nutrition, genetic variation and male fertility.

Infertility affects nearly 50 million couples worldwide, with 40-50% of cases having a male factor component. It is well established that nutritional status impacts reproductive development, health and function, although the exact mechanisms have not been fully elucidated. Genetic variation that affects nutrient metabolism may impact fertility through nutrigenetic mechanisms.

HFE Genotype and Endurance Performance in Competitive Male Athletes.

Introduction: Hereditary hemochromatosis can cause individuals to absorb too much iron from their diet. Higher tissue iron content, below the threshold of toxicity, may enhance oxygen carrying capacity and offer a competitive advantage. Single nucleotide polymorphisms (SNP) in the homeostatic iron regulator (HFE) gene have been shown to modify iron metabolism and can be used to predict an individual's risk of hemochromatosis.

Gluten Intake Is Positively Associated with Plasma α2-Macroglobulin in Young Adults.

Background: Gluten-free foods have increased in popularity over the past decade and are now being consumed by individuals without celiac disease. However, the physiologic effects of gluten intake in individuals without celiac disease remain unknown. High-abundance plasma proteins involved in inflammation, endothelial function, and other physiologic pathways may represent potential biomarkers of biological effects of gluten intake.

Plasma 25-hydroxyvitamin D, hormonal contraceptive use, and cardiometabolic disease risk in an ethnically diverse population of young adults.

Objectives: The relationship between vitamin D and cardiometabolic disease risk across ethnic groups is unclear, and it is not known whether the use of hormonal contraceptives (HCs), which affect vitamin D metabolism and are also associated with cardiometabolic disease risk, modifies this relationship. Our objectives were to determine the prevalence of vitamin D deficiency (plasma 25-hydroxyvitamin D [25(OH)D] < 30 nmol/L) to assess seasonal variation in concentrations of 25(OH)D, and to examine whether 25(OH)D is associated with cardiometabolic biomarkers across ethnic groups and across men, female HC nonusers, and female HC users in an ethnically diverse population of young adults living in Canada.

Methods: The study population consisted of Caucasian, East Asian, and South Asian individuals (n = 1384, 69% female) aged 20-29 years.

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.

Positive association between 25-hydroxyvitamin D and C-reactive protein is confounded by hormonal contraceptive use.

Background: Studies of the relationship between vitamin D and inflammation are equivocal. This may be due to unaccounted confounding. Hormonal contraceptive (HC) use is associated with elevated circulating 25-hydroxyvitamin D [25(OH)D] in Caucasians and African-Americans, but its effects on 25(OH)D in other ethnicities are unclear.

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.

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).