24 JEAN MAYER USDA HUMAN NUTRITION RESEARCH CENTER ON AGING 2016 PROGRESS REPORT 25 Eating for eyesight Age-related macular degeneration (AMD) is the leading cause of blindness in the United States. Sheldon Rowan, PhD, a scientist in the Nutrition and Vision Lab, and Assistant Professor at Tufts University School of Medicine, works to understand the events that lead to AMD and the role diet plays in it. “There is a strong association between diets containing excessive refined carbohydrates (high glycemic index) and AMD. I found that feeding aging mice with high glycemic index diets led to development of an AMD- like disease, whereas mice fed low glycemic index diets showed healthy normal eyes. Changing the diet from high glycemic to low glycemic index diets in the middle of the study completely prevented formation of AMD, indicating that disease progression can be halted or maybe even reversed with a healthy diet.” reports Dr. Rowan. He is now looking at the role that the gut microbiome plays in the onset of AMD. Behind the scenes of nutrition research Dr. Kathryn Barger took her interests in food, nutrition and statistics and found a home at the HNRCA after working in the pharmaceutical industry.  In her position as statistician, she collaborates with PhD students and principal investigators, to develop study designs and implement data analysis. Dr. Barger helps her fellow researchers at the HNRCA to answer questions like: How many subjects do I need to include in my study? What statistical test should I use to answer my research question? What data do I need to collect in order to get the best information from my experiment? Dr. Barger loves to promote good science through good statistics. Barger states, “I study methods to analyze multi-modal data, often 2 or 3 types of big data, such as metabolomics, dietary assessment data, and microbiome data. The data are the ingredients, and I identify the best preparation method needed to yield the most informative results.”.