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.

Genetics of Iron Metabolism and Premenstrual Symptoms: A Mendelian Randomization Study.

Background: Many women of reproductive age experience adverse psychological and physiological premenstrual symptoms. These symptoms may last for most of the reproductive years and can negatively affect the quality of life of many women. Some studies have examined the role of micronutrients in premenstrual symptoms, but the research on iron has been limited.

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.

ABO Genotype Does Not Modify the Association between the "Blood-Type" Diet and Biomarkers of Cardiometabolic Disease in Overweight Adults.

Background: Although 7 million copies of Eat Right 4 Your Type have been sold in >60 languages, there has been a lack of evidence supporting the "blood-type" diet hypothesis.

Objective: The present study aimed to examine the validity of this diet in overweight adults.

Methods: A total of 973 adults [mean ± SEM age: 44.

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.

ABO genotype, 'blood-type' diet and cardiometabolic risk factors.

Background: The 'Blood-Type' diet advises individuals to eat according to their ABO blood group to improve their health and decrease risk of chronic diseases such as cardiovascular disease. However, the association between blood type-based dietary patterns and health outcomes has not been examined. The objective of this study was to determine the association between 'blood-type' diets and biomarkers of cardiometabolic health and whether an individual's ABO genotype modifies any associations.

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.

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.

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.

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.

Association between circulating ascorbic acid, α-tocopherol, 25-hydroxyvitamin D, and plasma cytokine concentrations in young adults: a cross-sectional study.

Background: Inflammation and oxidative stress are associated with the development of numerous chronic diseases. Circulating ascorbic acid, α-tocopherol, and 25-hydroxyvitamin D (25(OH)D) may help reduce concentrations of pro-inflammatory cytokines through their antioxidant and anti-inflammatory properties. These micronutrients may act synergistically, and they may have different anti-inflammatory effects, but previous studies have assessed the link between each of these micronutrients and inflammation in isolation without controlling for the other micronutrients.

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].

Novel effects of hormonal contraceptive use on the plasma proteome.

Background: Hormonal contraceptive (HC) use may increase cardiometabolic risk; however, the effect of HC on emerging cardiometabolic and other disease risk factors is not clear.

Objectives: To determine the association between HC use and plasma proteins involved in established and emerging disease risk pathways.

Method: Concentrations of 54 high-abundance plasma proteins were measured simultaneously by LC-MRM/MS in 783 women from the Toronto Nutrigenomics and Health Study.

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).

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.