Grape powder and immune health in healthy middle-aged and older adults

The purpose of this study is to investigate the effects of consuming grape powder on immune profiles in healthy middle- and older-aged individuals. Specifically, the investigators are interested in evaluating the potential effects of grapes in influencing markers of immune function, inflammation, and metabolism that are known to change with aging. Grapes contain several nutrients and antioxidant polyphenols such as resveratrol, quercetin, vitamin K and fiber, which are known to promote heart and immune health. However, the effects of grapes on altering immune profiles within the context of aging is not well understood. Therefore, this study will explore how daily grape consumption impacts certain markers of immunity in healthy middle- and older-aged adults.

The main study procedures include consumption of a freeze-dried grape powder and control powder (which tastes the same but has none of the grape compounds that are being studied) mixed with water as a beverage on a daily basis for 4 weeks each. The investigators will additionally ask that participants avoid eating grapes and certain other antioxidant/grape-related foods and beverages throughout the 13-week study. Participants will additionally be asked to complete surveys about their diet, physical activity, and medical history, as well as provide blood samples and body weight measures throughout the course of the study. Participation in the study is expected to last about 6.25 hours over the course of 13 weeks and will include 7 visits.