How Fig Polyphenols Affect Blood Sugar and Insulin Levels After Eating in Adults at Risk for Diabetes

Recruited subjects must meet all eligibility criteria, sign and date a written Institutional Review Board (IRB)-approved Informed Consent Form.

The trial will test 2 dietary conditions which will be either the equivalent of one serving of dried California Mission Figs (40 g, ~120 kcal) or a calorie-matched control meal.

Pre-Screening: To learn more about the study and to pre-qualify, potential subjects can call the CNRC or visit the website posted on recruitment flyers or from other recruitment materials. If they call the CNRC, a staff member will provide a brief background on the study and ask a series of questions from a pre-screening questionnaire to see if they may be eligible to participate. The same questionnaire is available on the website and can be filled out by potential subjects online. The pre-screening questionnaire includes self-reported information about health status and lifestyle factors that can be used to determine if someone is not eligible for the study.

Information Session and Screening Session: Information Session and Screening Visit may occur simultaneously, or Information Session may occur prior to Screening Visit. Prior to the Screening Visit, potential subjects will be asked to arrive at the CNRC after an overnight-fast (stop eating after 10 pm) and be well-hydrated. Subjects should aim for drinking at least 8-10 cups of water the 24 h prior to the Screening Visit.

Information Session: At the CNRC, pre-screened subjects will participate in an Information Session where they will be informed of all study procedures and study schedules. If willing to adhere to all study procedures and schedules, they will be asked to read, ask questions, sign and date the Institutional Review Board (IRB) approved Informed Consent Form (ICF) before any laboratory or study screening procedures begin.

Screening Visit: After meeting eligibility criteria for blood glucose (BG) and blood pressure (BP) measures, subjects will advance to further screening procedures which will include anthropometric measurements (height, weight, waist circumference, body composition), BMI (calculated from height and weight), medical history, prior and concomitant medication, and dietary supplements use, and completion of a series of questionnaires relating to their general health and lifestyle. Woman under the age of 60 year, will be required to take a pregnancy test.

Pre-Study Visit: If the subject is qualified based on the screening results, the Pre-Study visit will take place immediately after the screening or on a later date. This visit lasts approximately 30-45 minutes, during which the subject will meet with one of the investigators who will provide detailed instructions on the study procedures and how to prepare for each study day. They will also receive training on study procedures, including dietary restrictions, medications and supplements to avoid, food recording, and overnight fasting requirements. The study dates will be scheduled, and they will receive a study booklet containing the study calendar and all the instructions covered during the Pre-Study visit.

Test Day Visits: The study is of two weeks with each visit having a follow up visit for a 24 hr blood draw. We will collect the three-day food record and verify that the subjects have fasted overnight, consumed a standardized dinner meal, avoided the specified food items, had sufficient sleep, and maintained dietary and exercise patterns consistent with the study procedures. Once everything is confirmed, we will measure their weight, body composition, vital signs (blood pressure, heart rate, and forehead temperature), and check their fasting blood glucose with a finger prick test. The visits include blood collection, urine collection, filling of the Online Dietary Questionnaire (ASA24) and GI tract diary. During each of the two study visits, blood will be collected eight times per visit, with a total of 120 mL of blood collected and four urine collection throughout the study across all visits.

Inclusion criteria

• Be between 30-50 years old.
• Have a BMI of 25-35 kg/m².
• Have fasting blood glucose between 100-125 mg/dL or Glycated hemoglobin (HbA1c) between 5.7-6.4%.
• Be non-smokers for at least 12 months.
• Be generally healthy, with no major organ-related diseases.
• Not take medications or supplements that could interfere with the study.
• Be able to follow study procedures, including dietary restrictions and scheduled visits

Exclusion criteria

• Smoker
• Vegetarian
• Taking over the counter supplements (e.g. fiber supplements, probiotics and/or prebiotics, antioxidants, anti-inflammation) and/or taking prescription medications that may interfere with study procedures or endpoints (e.g. Gastrointestinal medications, antibiotics) within the last 30 days
• Have cancer other than non-melanoma skin cancer in previous 5 years
• Taking unstable dose of hormonal contraceptive and/or stable dose less than 6 months
• Planning to become pregnant
• Pregnant and/or breast-feeding
• Excessive exercisers or trained athletes
• Excessive coffee/tea drinker
• Donated blood within last 3 months
• Have allergies/intolerances to foods consumed in the study
• Regular consumption of dried fruits exceeds > 2 servings per day
• Actively losing weight/ trying to lose weight (unstable body weight fluctuations of > 5 lbs in 3 months)
• Addicted to drugs or alcohol or have significant psychiatric or neurological disturbances
• Past smokers may be allowed in the study if stopped >2 years