Project 444572

High blood cholesterol (HBC) increases heart disease risk. In most cases, HBC outcomes from suboptimal lifestyle habits. However, more than 150,000 individuals in Canada and 34 million worldwide have HBC from birth due to inherited genetic disorders. People with inherited HBC (iHBC) face a very high risk of premature heart attack, which usually occurs before reaching 55 years old, if they are not adequately treated. Canada's Food Guide (CFG) emphasizes diets low in red and processed meats and high in plant foods as these are recognized to reduce heart disease risk in the general population. However, among individuals with iHBC, the impact of diet on heart health remains misunderstood. Over time, this has led to a misleading perception that diet, relative to cholesterol-lowering medication, is of little or no help in controlling blood cholesterol and preventing heart disease in people with iHBC. In fact, people with iHBC even report engaging in unhealthy dietary behaviors because of this perception. The objective of the proposed research is to document the impact of a diet reflecting CFG principles on heart health in adults with iHBC. We will conduct a feeding intervention in which adults with iHBC will consume a diet low in red and processed meats and high in plant foods, as recommended in CFG, and a diet reflecting current dietary habits of Canadians in a random order for 4 weeks separated by a 4-week break. Blood samples will be collected at the end of each diet from which we will first measure blood cholesterol levels. We will also use cutting-edge biochemistry techniques to measure a broad spectrum of small molecules in the blood to identify the blood signature of the healthy diet. Lastly, we will evaluate how the blood signature of the healthy diet is associated with heart disease risk in a separate cohort of nearly 1,000 adults with iHBC. With this research, we will demonstrate the crucial importance of diet for heart health among individuals with iHBC.