Isothiocyanates and Metabolic Health

Overview

Many sprouts, for example broccoli sprouts, contain substances that have shown to have protective effects, both against oxidative stress and against carcinogenic substances. In this study we will investigate the activation of the body's antioxidant defense system and effect on blood lactate and glucose after 1 week of isothiocyanate rich sprout supplementation. The subjects will perform maximal and submaximal work test, blood sampling, muscle biopsies and blood pressure monitoring post supplementation. We hypothesize that 1 week of supplementation of isothiocyanate rich sprouts alters blood lactate and glucose metabolism and activates the body's antioxidant defense system.

Many sprouts, for example broccoli sprouts, contain high levels of glucosinolates, which can be converted to the bioactive substances isothiocyanates. This conversion is assisted by another plant enzyme, myrosinase, which is released when the plant is mechanically processed. It is believed that this reaction is part of the plant's natural defense against pest insects and other animals that attack the plant in the early developmental stage. In cell and animal studies supplementation with isothiocyanates has been shown to induce the protein Nrf2 which is a so-called "Master regulator" of the body's antioxidant defenses and activates more than 200 genes that together provide a strong protection against oxidative and mutagenic stress. In this study we will investigate Nrf2 activation in human skeletal muscle and effect on lactate-, glucose metabolism after 1 week of isothiocyanate rich sprout supplementation. The study is a double-blinded, randomized, placebo controlled, cross-over study with 4 weeks wash-out between the interventions. We will perform maximal- and submaximal work test and monitor blood glucose and lactate during the tests. Also, in the post intervention phases we will perform muscle biopsies, glucose tolerance tests and monitor blood pressure. The hypothesis is that 1 week of isothiocyanate rich sprout supplementation activates Nrf2 in human skeletal muscle and alters blood lactate and glucose metabolism in rest and during exercise.