Grant: CIHR New Investigator

The brain develops until approximately 6 years of age, and is the tissue with the highest lipid concentration, after adipose tissues. Between the ages of 20 and 100, the brain undergoes physiological changes with the loss of nearly 20% of its weight - mostly in lipids. The brain is especially rich in long-chain fatty acids such as docosahexaenoic acid (DHA) and arachidonic acid (ARA). Docosahexaenoic acid (DHA) intake seems to be efficient in animal studies to promote neurodevelopment and prevent onset of cognitive decline but there is controversy towards this strategy in humans. My hypothesis is that DHA plays a role in human brain functions and cognition but this is conditional to DHA efficacy. In this program, we will investigate three conditions which we have found to alter DHA efficacy: aging, the presence of the APOE4 allele (most important genetic risk of Alzheimer's disease), and diabetic pregnancy. From this new starting point, I aim to answer these questions: what are the conditions needed to achieve efficacy, by which means could DHA supplementation benefit human brain function, does it necessarily involve cerebrovascular health? For this, we will complete our current randomized control trial (300 participants), we will test whether there are breakdown in the cerebrovascular system of APOE4 mice during aging, we will test the relation between DHA supplementation and cerebral oxygenation and vascular functions in humans and we will evaluate DHA transfer to the fetus during diabetic pregnancies and evaluate whether this is linked with neurodevelopment evaluated by electroencephalography. This program focuses on two of the most vulnerable populations suffering from brain diseases - the babies and the elderly - with the ultimate goal of promoting brain health throughout the entire life span.