Summary

Dates, rich in simple sugars, fiber, and antioxidant polyphenols, have a variable glycemic index and conflicting reported effects on type 2 diabetes. Moderate consumption might raise glycemia if added to the usual diet, but could improve insulin sensitivity and oxidative balance if used as an isocaloric substitute.

This prospective, interventional, single-center study (Endocrinology Department., La Rabta Hospital, Tunis) aims to evaluate the effect of daily consumption of 3 Deglet Nour dates for 8 weeks on glycemic control and oxidative stress in 130 well-controlled type 2 diabetic patients.

Primary objectives:

Assess changes in HbA1c, fasting glucose, and HOMA-IR. Measure variations in oxidative stress markers (MDA, SOD, TAC, pentosidine).

Secondary objectives:

Monitor changes in weight, BMI, waist circumference, and blood pressure. Assess tolerance, adherence, satisfaction, and adverse events.

Study design:

Baseline and final visits (week 0 and week 8) with clinical, dietary, and laboratory assessments.

Isocaloric substitution: 3 dates replace a carbohydrate portion (e.g., fruit or dessert).

No change in antidiabetic therapy or lifestyle allowed.

Endpoints:

Primary: ΔHbA1c, Δfasting glucose, ΔHOMA-IR, and oxidative markers. Secondary: Anthropometrics, blood pressure, safety, adherence, lipid and metabolic parameters.

Expected outcome: determine whether moderate, isocaloric date consumption is safe and potentially beneficial for metabolic control and oxidative balance in Tunisian patients with type 2 diabetes.

Inclusion Criteria:

• Age 18-65 years
• Type 2 diabetes diagnosed for at least one year
• Well-controlled diabetes on oral antidiabetic drugs for at least 3 months, with a target baseline HbA1c < 8%
• Duration of diabetes < 15 years
• Patient available for an 8-week period
• Written informed consent

Non-inclusion Criteria:

• Patients on insulin therapy
• Oral antidiabetic treatment modified within the 3 months prior to inclusion
• Diabetes with established microvascular or macrovascular complications
• Severe intercurrent diseases (severe renal insufficiency, severe liver disease, cardiovascular history, neoplasia, inflammatory disease)
• Pregnancy or breastfeeding
• Known allergy or intolerance to dates
• Dietary regimens incompatible with isocaloric substitution (e.g., strict ketogenic diet, prolonged fasting)
• Inability to understand or comply with study instructions (cognitive impairment, language barrier without interpreter, major logistical constraints)

Exclusion Criteria:

• Initiation of insulin therapy or major modification of antidiabetic treatment
• Occurrence of pregnancy during the study
• Development of a serious adverse event attributable to the intervention (e.g., persistent hyperglycemia, acute metabolic complications)
• Patient refusal to continue the study or withdrawal of informed consent
• Major non-adherence to the intervention (<80% of planned intake or absence of isocaloric substitution)
• Detection of a severe intercurrent condition requiring discontinuation of the intervention (e.g., heart failure decompensation, severe infection)
• Loss to follow-up preventing the assessment of primary endpoints