Intro: I’m Asia Chandler with another Ask a Scientist  episode with Dr. Alison Brown from the National Heart, Lung, and Blood Institute at NIH. Dr. Brown, we’ve been talking about the Dietary Approaches to Stop Hypertension or  DASH eating plan and the science behind it. 

AC: So what do scientists who study diet actually study? 
 
AB: Scientists who study diet may study diets or nutrient intakes and how these impact our health, such as high blood pressure, blood pressure levels, cholesterol, weight and blood sugar levels. And they do this through clinical trials where participants are randomly placed in either an intervention group or the control group for a certain period of time. In these studies, participants are either provided their meals or given guidelines for diets to adhere to. 
 
AC: Are there other types of studies beyond clinical trials? 
 
AB: Scientists also conduct what are known as epidemiological studies, where they observe study participants in their natural living and compare health outcomes between participants with different dietary intakes. These observational studies are very helpful in understanding how certain diets may impact health. 
 
Outro: For more information about the DASH eating plan visit nhlbi.nih.gov.