Anti-Inflammatory Activities of Grapes in Humans at Risk for Cardiovascular Disease
Who is conducting this study?
The study is conducted by Susan Zunino, PhD. The study has been reviewed and approved by the UC Davis Committee for the Protection of Human Studies. There is only minimal health risk associated with participation in this study.
What is the purpose of the study?
The study will test whether drinking beverages made from grape powder will decrease markers of inflammation, improve cholesterol levels and blood lipid profiles, and change immune responses that may reduce the risk of heart and blood vessel disease.
Who can participate?
Healthy, non-smoking, men and women, ages 20 - 60 years, and approximately 45-120 pounds overweight may be eligible to participate. Volunteers must be willing and able to come to the research center (WHNRC) on the UC Davis campus for 6 study visits and be able to commit to the study schedule for 9 weeks. Volunteers must be willing to drink two beverages per day containing grape powder.
Who is NOT eligible to participate?
Adults who are:
- younger than 20 and older than 60 years
- smokers, or currently using tobacco products
- taking medications for cholesterol, thyroid, asthma, or blood pressure
- using weight loss products or trying to lose weight
- following a vegetarian diet, and
- Women who are pregnant, lactating or planning a pregnancy
What do I need to do to participate?
You will complete a health screening at WHNRC, 430 West Health Sciences Drive on the UC Davis campus. The screening visit will last about 60 minutes, and will occur in the morning after an overnight fast. This means that no food or drink is consumed for 12 hours prior to the appointment, but water is allowed and encouraged. A blood sample will be taken for measurement of blood chemistries and lipids, and to check for anemia. A health history questionnaire will be completed.
If you are selected as a participant in this study, you will be asked to participate in the study for a total of 9 weeks. During this time, volunteers will be instructed to maintain their normal dietary habits with the following exceptions: we ask that you maintain a diet low in fruits and vegetables (maximum 4-5 servings per day), limit consumption of tea, coffee, wine, and chocolate to one serving per day each or less, and stop the use of dietary supplements during the course of the study. You will be allowed to consume one multi-vitamin mineral pill that does not contain added antioxidants allowed per day, if you choose.
During the first week of the study, you will come to the WHNRC for two fasting blood draws, on Monday or Tuesdays, one-week apart (Blood draw #1 and #2). This is the baseline period and everyone will participate in the baseline. After the baseline period, half of the volunteers will be randomized to the grape powder and half to placebo powder for three weeks. For the 3 weeks of intervention that involve the powders, you will pick up packets of grape or placebo powder from WHNRC once per week and store them in your freezer at home until use. Each packet will contain the equivalent of approximately 2 servings of fresh grapes (46 grams of powder), or similar ingredients (placebo powder).You will be instructed to add the powder to 8 fl oz. of water, stir, and consume the beverage. You will be asked to consume this beverage two times per day, once with breakfast and once with dinner. You will be provided a booklet to record the consumption of the beverages and any adverse events you may experience. After 2 weeks of intervention and again at the end of the three-week intervention, you will have a fasting blood draws on Monday or Tuesdays (Blood draw #3 and #4). During these three weeks we will estimate your dietary intake by three unannounced 24-h dietary recalls obtained by telephone using an interview method.
Following blood draw #4, you will have a two week washout period when you will not come to the WHNRC and will take no beverages at all. Next, you will have a three-week cross-over to the other packets for an additional three weeks. You will again pick up packets of grape or placebo powder from WHNRC once per week and store them in your freezer until use. You will add the powder to 8 fl oz. of water, stir and consume the resulting beverage. You will be asked to consume this beverage two times per day, once with breakfast and once with dinner, and to record the consumption of the beverages and any adverse events you may experience in your booklet. At the end of the second three-week intervention, you will have two fasting blood draws on Mondays or Tuesdays (Blood draw #5 and #6). During these three weeks we will estimate your dietary intake by three unannounced 24-h dietary recalls obtained by telephone using an interview method.
What is in the grape powder?
The freeze-dried grape powder is a composite of commercially-grown, fresh, red, green and blue-black California grapes (Vitis vinifera, seeded and seedless varieties), that represent the majority of grapes available to consumers. Whole grapes are freeze-dried and powdered, and silicon dioxide added as a flow conditioner/anti-caking agent.
What is in the placebo powder?
The placebo powder was formulated to closely match the freeze-dried grape powder. The placebo contains fructose, glucose (the two main sugars in the grape powder), organic acids including tartaric, malic and citric acids, and fiber. The fiber comes from a blend of powdered cellulose, sugar beet fiber and cellulose gel. Artificial colors (FD&C approved dyes) are used to replace natural color. Flavorings are also added. The placebo powder also contains modified food starch and tapioca maltodextrin, potassium salts, and silicon dioxide.
Who supplied the grape and placebo powder?
Packets of grape and placebo powder will be supplied by the California Table Grape Commission. Both the freeze-dried grape powder and the placebo powder were made by The National Food Laboratory, Inc. (Dublin, CA) for the California Table Grape Commission using good manufacturing practices. These powders have been used by other investigators funded by the Commission with no adverse effects reported.
What are the benefits to you from this study?
You will receive monetary compensation up to $280 for completion of the study.
What should I do if I have questions?
Call (530) 752-5177 and press #2
