David Mutch, Professor

Human Health and Nutr Sciences
University of Guelph

Investigating the effects of milk protein versus soy protein on essential omega-3 fatty acid metabolism

Dairy products provide macronutrients, vitamins, and minerals that are important for health and development. Despite this, many Canadians are eating fewer dairy products and are instead consuming more plant-based alternatives like soy, partly due to misconceptions about the effects of dairy on health. For example, many people believe that dairy can increase the risk of heart disease. However, compared to soy, dairy may actually improve heart health due to its effects on the desaturase enzymes that synthesize omega-3 fatty acids, such as EPA and DHA. We recently reported that young healthy Canadian adults who consumed dairy beverages and dairy-containing foods had higher desaturase activity compared to individuals who consumed soy beverages and soy-containing foods. The goal of this presentation is to provide attendees with an overview of the relationship between soy and desaturase enzymes, and highlight results from a recent mouse feeding intervention study examining the effects of a soy protein isolate (SPI) on omega-3 fatty acid metabolism compared to skim milk powder (SMP). Briefly, we found that male and female mice fed SPI had lower hepatic EPA compared to mice fed SMP, but this did not stem from changes in hepatic desaturase gene or protein expression. Liver microsome assays confirmed a reduction in delta-6 desaturase activity. Collectively, this research will advance understanding of how dairy and soy proteins regulate omega-3 fatty acid metabolism and provides evidence supporting a previously unappreciated protective effect of dairy for human health and development.

Speaker/Chair Bio:

Dr. Mutch is a Professor in the Department of Human Health & Nutritional Sciences at the University of Guelph, Canada. He received his Ph.D. from the University of Lausanne Switzerland, and completed post-doctoral fellowships at The Scripps Research Institute in San Diego and the French National Institute for Health and Medical Research in Paris. Dr. Mutch leads a nutrigenomics research program that investigates the mechanisms that regulate lipid metabolism in the body, with a major focus on diet-gene interactions in adipose (fat) tissue, skeletal muscle, and liver. His team aims to advance understanding of the genetic and diet regulation of fatty acid desaturases (key enzymes involved in endogenous fatty acid synthesis), and their association with cardiometabolic outcomes. Ongoing research in his lab uses cell and rodent models to explore how altered desaturase activity and dietary fatty acids influence cellular processes such as adipogenesis, lipogenesis, and lipolysis. Dr. Mutch also investigates if FADS genes can be used to personalize omega-3 dietary habits to improve an individual’s health and well-being. Dr. Mutch is Editor-in-Chief of Lifestyle Genomics, and has published over 120 peer-reviewed articles in the fields of obesity, fatty acid metabolism and nutrigenomics.