Grant: Project Grant

The preservation of cognitive abilities is of primary importance to older people as cognitive decline and dementia result in loss of independence and decreased quality of life. Currently, an estimated 40% of Canadians over >65 y are reported to experience some form of memory loss. Lifestyle factors such as nutrition and exercise can significantly influence cognitive abilities in older age. Historically discovered for its role in blood coagulation, vitamin K (VK), has recently emerged as an important nutrient for brain function and cognition. In recent years our group has conducted pioneering studies in which we report strong positive associations between VK nutritional status and performances in global cognition and specific cognitive domains in various older adult populations. Although these epidemiological studies support a role for VK in brain function, only an intervention trial will confirm the specific action of VK in brain. We hence propose to conduct a 24-week randomized, double-blind, placebo-controlled study aimed at determining the benefit of VK supplementation on cognition in older individuals at risk of cognitive impairment. Our primary objective will be to determine the impact of VK supplementation on cognitive domains known to be affected during aging; our secondary objective will be to characterize the mechanisms of action of VK in brain in a sub-group of participants, by assessing brain activity during a MRI word-pair recognition task. The Canadian population is aging rapidly and preventive initiatives aimed at decreasing and delaying cognitive decline are urgently needed. Given its wide range of physiological actions, VK has the potential to clinically impact cognition in older adults at risk of cognitive impairment. The proposed trial will be, to our knowledge, the first of its kind to be conducted and will provide essential information that will inform future recommendations for this vitamin in the context of a global diet.