Project 462701

Cardiovascular disease (CVD) is the second leading cause of death in Canada, affecting ~2.4 million adults age 20 y and over. Several studies have associated CVD such as coronary heart disease (CHD) with cognitive decline and dementia. Historically discovered for its role in blood coagulation, vitamin K (VK) is now considered an important nutrient for the vasculature and brain function. In population studies, higher VK status has been associated with lower arterial stiffness and better overall vascular health. In recent years, our team has conducted pioneering studies in elderly populations providing evidence for the beneficial effects of VK in cognition, notably memory. Here, we propose to conduct a 12-week intervention pilot study with the general objective to obtain a preliminary assessment of the effect of a VK1 supplementation on cognitive performance and vascular function in men and women with stable CHD. Participants will be stratified by sex and randomly assigned to one of two groups: (1) VK1 supplemented [500 mcg/d; n=20] or (2) placebo [n=20]. Synthesized in plants (e.g., green leafy vegetables, certain oils, herbs), VK1 has no known toxicity and the proposed dose has been used successfully in previous trials focusing on bone and vascular health. Primary outcome will be changes in cognitive performance (e.g., memory, speed to process information) between baseline (T0) and end of study (T12). Secondary outcome will be changes in vascular measurements (e.g., arterial stiffness, vascular reactivity) between T0 and T12. Individuals with CHD are at increased risk for cognitive impairment as they age. Given its basic actions, VK has the potential to clinically impact cognition in adults with CHD. The proposed pilot trial will be, to our knowledge, the very first to focus on this topic and will provide essential preliminary information that will serve to plan the full-scale study.