Dietary Oxysterols and β-Cell Function Among African Americans

Prior treatment

• Be currently on a vegan, vegetarian, or any type of plant-based diet for the 3 months prior to recruitment: Participants currently on these diets may not see significant changes on the dietary interventions of the study protocol.

Other illness

• Be on dialysis or have any stage of renal failure: Dialysis patients need special diets and more intense monitoring than is planned for the participants in this study.
• Have food allergies: Participants will be screened for food allergies. This is to prevent food sensitivities or adverse reactions to the prepared meals in the study.

Lab values

• Be taking statin medications or any other cholesterol lowering drugs or supplements: These medications may artificially lower serum cholesterol and oxysterol levels.
• Be on medications or supplements to lower blood glucose or treat diabetes: This will be an effect modifier or confounding factor. We will not know the effect of the dietary intervention if the participants are also on medications for diabetes.
• Be status post blood transfusion in the previous 3 months: This will interfere with the test for HbA1c levels. This is one of our primary outcomes:
• Have a hemoglobin or any other blood disorder: This will interfere with the test for HBA1c which measures glycation of hemoglobin in red blood cells.:

Other

• Be pregnant or lactating: Fetuses and breast-feeding infants are a protected vulnerable group. The risk of involving them in research must outweigh the benefits, Hormonal levels and other factors in pregnant and lactating woman may confound study results.
• Be a current smoker: Smoking is a risk factor for oxidative stress - this could be an effect modifier or a confounding faction for this study.
• Be taking biotin supplements: This interferes with the test for fasting C-Peptide.

• HbA1c: 5.7% - 7.0%: This HbA1c range reflects mild to moderate β-cell dysfunction.
• Self-identified AA: This group has higher rates of T2D than the general population.
• Adults over18 years old: This age group is at higher risk of T2D.
• Ability to read, understand and communicate effectively in English: All information about the study and instructions for the study protocol will be in English.
• Committed to eating the allocated study diet for 12 weeks: This is important to ensure that the study protocol is followed, and the data collected from participants is meaningful/valid.
• On stable medication dosages for the three months prior to recruitment: This is to avoid bias or confounding with new medications or dosages changes.
• Able to safely store a week's supply of prepared meals: Participants will receive packages of prepared food that has to stored and last them for the following week.
• Mentally competent and able to follow the study protocol and provide informed consent
• Currently eating the Standard American diet: The baseline diet of the participants will be assessed and correlated their baseline serum 7-KC levels and HOMA2 Index of β-cell function.