Stress and Nutrition Research Program
Sheila G. West, Ph.D.
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 walnuts, canola oil, fatty acids, and culinary spices on cardiovascular responses to stress and vascular endothelial function.
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.
Students and postdocs in the Vascular Health Interventions Lab are active contributors in all stages of research with human subjects, including: grant writing, ethical issues, processing biological samples, statistics, recruiting and scheduling participants, and conducting dynamic tests of of blood pressure and vascular function in the clinic. In addition to training in scoring vascular ultrasound images, students develop expertise in psychophysiological techniques for measuring cardiovascular response to stress, such as heart rate variability and impedance cardiography. Through collaborations with other laboratories, students gain experience with genomic techniques and biochemical assays of blood collected from our clinical studies. Many of our alumni have gone on to graduate study in medicine and research positions in industry. For information about training in the lab, please click the Student Research Link.
Equipment and Resources
The lab has testing rooms located in Health and Human Development Bldg. and The General Clnical Research Center. We have three cardiovascular testing suites for measuring stress responses. Equipment includes: Minnesota and Hutcheson impedance cardiographs with EKG, Dinamap blood pressure monitors, and customized software (COP) for estimating stroke volume, cardiac output, heart rate variability, and other parameters heart activity. We own an Acuson Aspen high frequency clinical ultrasound with cardiac and vascular probes and a Vascular Tools workstation to digitize and score vascular images. The lab also includes 2 Endo-PAT arterial tonometry devices. At the GCRC (www.gcrc.psu.edu) testing site, we work with nurses who are responsible for collecting blood samples and conducting EKG studies. The GCRC provides sample processing space, including calibrated pipetters, a refrigerated centrifuge and ultralow temperature freezer. Collaborations with other labs give our students and technicians access to a wide variety of specialized instruments.
The research office for the Vascular Health Lab is located in room 122 Health and Human Development Bldg East. Please contact us if you are interested in volunteering for one of our research projects or if you would like to gain research experience by working in the lab.