Clinical Research Directory

Metabolite Changes Following Consumption Of Different Protein Drinks In Singapore Older Adults

The study aims to investigate the acute effects of different protein sources (i.e., casein, whey, soy) on metabolomic profiles (e.g., amino acids in the blood), along with other outcomes such as cognitive function, mood, and appetite. While the study does not directly aim to prevent, prognosticate, diagnose, or alleviate any disease, it may provide insights that could inform dietary recommendations and support disease prevention efforts in older adults.

Diet Synergy in Muscle Protein Synthesis

In the present semi-crossover randomized design, 15 recreationally active young adults (19-40 y) will receive stable isotope tracer infusions and perform a single bout of resistance exercise. Immediately after exercise, participants will ingest either 1 medium russet potato with skins and 2 ounce-equivalent lean ground beef combination (274 kcals, 19.3 g protein, 5 g fat, 37 g carbohydrates, and 4 g fiber), 2 slices of white bread and beef combination (262 kcals, 19.8 g protein, 6.8 g fat, 28 g carbohydrates, and 1.8 g fiber) or 2 ounce-equivalent beef (93% lean meat/7% fat; 110 kcals, 14.8 g protein, and 5 g fat). Repeated blood and muscle biopsies will be collected to determine whole body leucine kinetics, amino acid concentrations, anabolic signaling and myofibrillar protein synthesis rates during the trials.

Validating IAAO for Muscle Outcomes

Consuming dietary protein stimulates whole-body and muscle protein synthesis, the latter of which is typically measured using invasive primed constant infusions of stable isotopes with concurrent muscle biopsies. Alternative non-invasive methodologies have been developed (namely the indicator amino acid oxidation (IAAO) technique) to estimate the impact of protein ingestion on whole-body protein synthesis as a proxy for determining dietary protein requirements. Given that the IAAO technique is based on principles of protein metabolism which occur in the liver, it is unclear how representative the IAAO outcomes of whole-body protein synthesis is to skeletal muscle protein synthesis. Validation of the IAAO technique against gold-standard, biopsy-derived measures of muscle metabolism (i.e., muscle protein synthesis) would assist in mitigating the invasiveness of muscle physiology and nutrition research.

Menstrual Cycle vs. Oral Contraceptives: Effects on Muscle Protein Metabolism After Resistance Exercise

The muscles of the body are constantly breaking down old proteins and building new ones. These two processes, protein breakdown and protein synthesis, together are known as protein turnover. Protein turnover is essential for maintaining healthy muscle. Despite its importance, females have historically been underrepresented in protein metabolism research. A long-standing assumption has been that fluctuations in female sex hormones such as estrogen and progesterone, whether across the natural menstrual cycle or in individuals using oral contraceptives (OCs), make metabolism and training responses too variable to study. Because of this, many researchers have excluded female participants for logistical reasons. Resistance exercise, such as weightlifting, is the most effective way to increase muscle size and strength. Each resistance-training session triggers muscle protein synthesis (MPS), the process by which new muscle proteins are built. Consuming dietary protein or individual amino acids further increases the rate at which new proteins are formed. Over time, higher rates of protein synthesis support muscle growth and the maintenance of other lean tissues in the body. The purpose of this study is to examine how menstrual cycle phases and OC use influence the synthesis of proteins in both muscle tissue and the rest of the body. Improving scientific understanding in this area will support more effective, evidence-based training and nutrition recommendations for females.

Anabolic Response to Beef vs Plant Protein in (Pre)Frail Older Adults Using a Novel Stable Isotope Pulse Method

Frailty is a common clinical syndrome in older adults that increases the risk for poor health outcomes including falls, disability, hospitalization, and mortality. Previous research showed increased protein needs and reduced anabolic response to meals in older adults, indicating the need for proteins with a high anabolic capacity to prevent and attenuate physical and cognitive health decline throughout the frailty cycle. Recently, more people have chosen to eliminate animal (i.e., beef) products from their diets which is concerning because of beef's anabolic properties due to high essential amino acid (EAA) levels and many other positive health effects. The Researchers' recently developed stable isotope amino acid pulse method enables measurement of the true intracellular anabolic response to a meal and bioavailability of food-derived amino acids. The research objective is to examine differences in the anabolic response and bioavailability of individual EAA and non-essential amino acids (NEAA) in beef as compared to plant protein in older adults with and without (pre-)frailty.

Prandial Metabolic Phenotyping in Sarcopenic Older Adults Comparing Plant Based and Whey Based Protein

The researchers overall objective is to determine whether plant and animal protein based proteins affect the anabolic responses across aging populations differently due to specific changes in the essential amino acids (EAA) and non-essential amino acids (NEAA) kinetic responses. The researchers central hypothesis is that a high EAA to NEAA ratio in a protein meal is related to higher anabolic response to the meal. The researchers also hypothesize that the type of NEAA in a protein meal also affects the anabolic capacity of the meal. The researchers rationale is that finding the amino acid composition of a meal that will maximally induce protein anabolism will guide novel nutritional approaches to prevent and treat sarcopenia, thereby reducing both overall economic burden and improving individual patient outcomes.

Peanut Sip Feeding Protocol

Peanuts are considered a functional food and regular consumption is associated with positive health effects. Protein is the second most common nutrient in peanuts after fat. The protein digestibility of peanuts is similar to that of animal protein, and the limiting amino acids in peanuts vary based on the study and are suggested to be lysine, methionine, or threonine. Defining the reduced responsiveness of various dietary proteins to induce anabolism in older adults is critical for preventing and attenuating physical and cognitive health decline.

Stable Isotopes- Adults With Obesity

In a crossover design, 8 participants will receive caloric drinks containing stable isotopes. In one arm of the study, participants will consume 6 hourly drinks containing two stable isotopes. Repeated blood, breath, urine, and muscle biopsies will be taken. In the second arm, participants will consume 1 drink containing 75g glucose, labeled with two stable isotopes of glucose. Periodic blood and breath will be taken over three hours.

Prandial Metabolic Phenotype in Adults

Previous studies suggest that changes in metabolism due to the effects of aging might serve as a potential for therapeutic agents. The investigating lab developed a pulse method combining multiple stable isotopes to study multiple metabolic pathways in the same individual simultaneously. By measuring whole-body metabolism in a large group of older adults, the investigators may be able to unravel age-related deterioration in protein turnover (synthesis and breakdown) that contributes to impaired functional capacity. Metabolic profiles could explain differences in pathways in the aging process with special interest in metabolism of amino acids as they have been associated with aging-related disorders.

Animal and Microbial-based Dietary Protein Efficiency in Adults

Given the relatively high carbon footprint and sustainability of animal-based proteins, there is a growing interest in determining the nutritional quality non-animal-based protein sources. The overall objective of this investigation is to examine the impact of different animal and microbial-based protein sources to support whole body protein synthesis in adults. To do this, investigators will employ a 'breath test' method developed in our laboratory as well as urine sampling. The results of this study will allow us to better understand the impact of dietary protein quality for maintaining health and body protein mass in adults.

Milk Vs Wheat Protein Intake to Maximize Whole-body Protein Synthesis Rates in Healthy Older Adults

Dietary protein intake is essential for tissue renewal and growth. Current recommendations for protein intake are based on studies using egg protein as reference protein. Egg protein is an animal-based protein with a high quality. Protein quality is determined by the composition of (essential) amino acids and digestibility. Therefore, different proteins have a different quality. Due to the environmental crisis, an increasing number of people consumes more plant-based proteins. These plant-based proteins often have a lower protein quality compared to animal-based proteins. Therefore, the aim of this study is to investigate whether optimal protein intake depend on protein quality. The optimal protein intake of an animal-based protein with a high quality (milk) will be compared to the optimal protein intake of a plant-based protein with a low quality (wheat).

Oral 'Breath Test' to Measure Anabolic Sensitivity to a Protein Meal Across the Age and Physical Activity Spectrum

The purpose of this study is to determine how anabolic sensitivity, in response to the ingestion of a liquid protein meal, differs across the lifespan, between biological sexes, and with varying physical activity levels.

The Role of Nutrition in Muscle Function of Bariatric Surgery Patients

Current recommendations for protein intake after bariatric surgery are not based on strong scientific evidence. It remains unclear how much protein should be eaten to minimize muscle loss and preserve the metabolism and function of individuals post-bariatric surgery. The objective of this study is to analyze the relationships between changes in body composition, nutrition and protein intake, and muscle function after bariatric surgery to further our understanding of the nutritional needs of patients after bariatric surgery. We intend to recruit around 75 participants, men and women, aged between 18 and 65 years. Participants will be recruited from the Bariatric Surgery Clinic, McGill University Health Center.