The mission of the Stress and Nutrition Research Group and the Vascular Health Interventions Lab is to measure the effects of specific foods and nutrients on multiple coronary risk markers, including cardiovascular responses to stress.
Our clinical studies have documented beneficial effects of walnuts, pistachios, calcium, L-arginine, and complex dietary patterns on emotional and physical response to stress. The ultimate goal is to design dietary strategies to reduce the biological impact of stress on the vascular system. We study healthy adults with cardiovascular risk factors (including elevated LDL cholesterol, high triglycerides, abdominal obesity, type 2 diabetes, hypertension, and polycystic ovary syndrome).
Current studies examine the effects of dark chocolate, omega-3 fatty acids from fish and flax, high protein diets, nuts, and magnesium on dynamic measures of vascular health.
In addition to measuring blood pressure and vascular responses to stress, we use ultrasound to measure diet-related changes in “flow-mediated dilation” in the main artery serving the forearm. In those studies, we work with a vascular sonographer to collect images of the artery walls. Students in the lab use custom-designed software to measure arterial landmarks. Longitudinal studies have shown that impaired dilation is an important, early marker of atherosclerosis risk. Recently we added peripheral arterial tonometry to our battery of vascular tools, and we can also measure changes in arterial stiffness. Typical studies also examine effects of foods and nutrients on glucose and lipid metabolism, inflammation, gene expression, oxidation, and stress hormones. Dr. Sheila West is the director of the laboratory.
We collaborate with Penny Kris-Etherton, director of the Metabolic Diet Study Center. Dr. Kris-Etherton is a highly-regarded expert in lipid metabolism and the design of controlled metabolic studies. In the “controlled feeding” paradigm, diet center staff carefully design, prepare, and deliver all meals and snacks to research participants for 4 to 12 weeks at a time. They are required to eat one meal per day in the diet center during the week, and all other meals are packed for consumption off site. This rigorous methodology allows us to control the macronutrient content of the diets so that subtle changes can be made in fatty acids, protein or carbohydrates. Most of our data collection occurs at the General Clinical Research Center, an NIH funded center that provides nursing support, testing rooms, screening EKGs, and phlebotomy.
We also work closely with Dr. Laura Klein, director of the Behavioral Neuro-Immunology Laboratory. Dr. Klein is an expert in biological assays and the design of acute stress protocols. We also collaborate with Jack Vanden Heuvel, director of the Penn State Center for Excellence in Nutrigenomics (http://nutrigenomics.psu.edu/). Dr. Vanden Heuvel’s laboratory identifies genes that are activated by the nutrients contained in our dietary interventions.