Clinical Research Directory

Effect of Dietary Nitrate on Immobilization-induced Changes in Skeletal Muscle in Young Healthy Men

Diminished use of skeletal muscle, such as occurs with many chronic diseases (e.g., heart failure or cancer cachexia), denervation, bedrest, immobilization (e.g., limb casting or bracing), etc., is a common clinical condition affecting untold millions of individuals each year. Such disuse leads to a rapid decline in muscle fiber area and hence whole muscle size, contributing to a decrease in strength, speed, and power as well as alterations in energy metabolism. Collectively, these changes lead to reduced physical function and contribute to the seriousness of any disease, illness (e.g., pneumonia), surgery (e.g., joint replacement), or injury (e.g., broken bone) accompanied by decreased muscular activity. Currently, there are no effective pharmacological treatments to prevent disuse-associated muscle wasting in humans. The above-described effects of disuse appear to be due, at least in part, to a decrease in nitric oxide (NO) bioavailability. Reduced synthesis of NO and/or increased NO destruction (due to increased production of oxygen free radicals) likely contributes to the mitochondrial changes, energetic abnormalities, and muscle atrophy resulting from immobilization. The objective of this study is to investigate the potential benefits of dietary nitrate supplementation on immobilization-induced changes in muscle contractile function and mitochondrial respiratory capacity in young healthy men. Our disuse-induced muscle atrophy model will involve wearing a knee brace for a period of 14 d.

Evaluating the Impact of Various Dietary Nitrate Supplements on Oral Health

This study aims to investigate the effects of different dietary nitrate supplements, versus placebo, on microbiological and immunological markers associated with oral health in people aged 18-65 years. The main research questions are: * How do different dietary nitrate supplements (beetroot crystals vs. beetroot juice) affect oral health markers, including salivary pH and oral microbiome composition? * What is the acceptability and ease of integrating one of dietary nitrate supplements, made from beetroot but processed as freeze dried crystals or juice, into the daily diet? To answer these questions, the study will compare results from three groups of participants, who will be randomly assigned to one of the following study arms: Group 1: The control group will consume a placebo beetroot supplement completely free of nitrate in juice form. Group 2: The beetroot juice group will consume a beetroot supplement standardised to contain \~ 400 mg of nitrate in juice form. Group 3: The beetroot crystals group will consume a beetroot supplement standardised to contain \~400 mg of nitrate in freeze dried crystal form. The study will follow a randomised, single-blind, placebo-controlled, parallel design, and the intervention will last for four weeks. Data will be collected by providing pre- and post-intervention saliva samples tongue swabs, and various questionnaires will be completed at baseline and at the end of the study. In addition, at the end of the second week of the intervention period, participants will be asked to collect a saliva sample over three consecutive days at home.