Effects of Freeze-dried Grape Powder on Immune Profiles in Healthy Aging Adults

Launched by UNIVERSITY OF CONNECTICUT · Jul 22, 2025

Keywords

ClinConnect Summary

This clinical trial is studying how daily consumption of freeze-dried grape powder might affect the immune system and inflammation in healthy adults aged 50 to 75. Grapes have nutrients and antioxidants—like resveratrol and vitamin K—that are thought to support heart and immune health. The researchers want to see if eating grape powder can improve certain markers of immune function and metabolism that often change as people get older.

If you join the study, you will drink a grape-flavored powder mixed with water every day for four weeks, and during another four weeks, you’ll drink a similar-tasting powder without the grape ingredients. You’ll be asked to avoid eating grapes and some other foods rich in antioxidants during the 13-week study. The study involves about seven visits over this time, where you’ll provide blood samples, have your weight measured, and complete surveys about your diet and physical activity. To be eligible, you need to be between 50 and 75 years old, have a body mass index (BMI) within a healthy range, and be generally healthy without certain medical conditions or medications. This study is a good fit for adults interested in learning more about how grapes might help support a healthy immune system as they age.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • 50-75 years old (at time of screening)
• • Body mass index (BMI) 18.5 to \< 30 kg/m2
• • Willing to consume grape and control powder during study periods, and refrain from eating grapes and certain other polyphenol-rich foods and beverages during the study
• • Do not fit any exclusion criteria
• Exclusion Criteria:
• • \<50 years old and \>75 years old
• • BMI \<18.5 and ≥ 30 kg/m2 or body weight \< 110 pounds
• • Experienced \>10% weight change in the past 4 weeks
• • Elevated fasting glucose levels (fasting glucose higher than 126 mg/dL) and triglycerides greater than 500 mg/dL
• • Self-reported and/or physician-diagnosed history of diabetes mellitus, coronary heart disease, stroke, renal or liver disease, cancer, eating disorders, certain severe and/or relapsing/remitting autoimmune, inflammatory, or metabolic diseases, chronic infections, scleroderma, blood clotting disorders, intravenous drug use, or current pregnancy or lactation
• • Allergy to grapes or any ingredients in the grape or control powders
• • Implanted medical device (e.g., pacemaker) or other health condition that would prevent measurement of body composition by bioelectrical impedance
• • Currently taking lipid-lowering medications (e.g., statins, fibrates), glucose-regulating medications, anti-inflammatory medications (e.g., non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids), or medications that primarily affect blood clotting (e.g., warfarin), long-term antibiotics in the last 3 months, active use of probiotics during the intervention
• • Active smoker