Effectiveness of royal jelly supplementation in glycemic regulation: A systematic review

Table 1 Human trials examining acute effects of royal jelly treatment

Ref.	Study design	Subjects	Treatment	Outcome measures	Effectiveness
Iaconelli et al[24]	Crossover study	N = 10 + 10 healthy individuals and individuals with type 2 diabetes	Each subject went through three studies on different days: 0 g, 12 g, or 23 g of sebacic acid substituted fats in a meal	Glucose clearance: Postprandial	Significantly improved glucose clearance in diabetic subjects only in dose-dependent manner (d = -1.70)
				Insulin secretion/clearance rate	Significantly improved GLUT4 expression (d = 0.81) and glucose uptake in L6 cells (d = 0.67)
				GLUT4 expression in L6 myotube cells	Insulin secretion/clearance decreases significantly in similar fashion between healthy and diabetic patients. Dose-response relationship. For diabetics, d = -1.12
Mobasseri et al[25]	Randomized controlled trial	N = 20 + 20 adults with type 2 diabetes aged 30-65 in control and treatment groups	15 g of royal jelly ingested orally after overnight fasting	Hyperglycemia: Fasting blood glucose, glucose clearance after royal jelly consumption	No significant difference in outcome measures between two groups
				Hyperinsulinemia: Serum c-peptide and insulin
Münstedt et al[26]	Controlled trial	N= 10 + 10 healthy males, split into experimental and control groups	20 g of fresh royal jelly ingested orally	Glucose clearance: Plasma samples during OGTT	Significantly increased rate of glucose clearance (insufficient information for effect size calculation)
				Insulin resistance: Serum insulin and c-peptide	No significant change in serum insulin profile
Münstedt et al[27]	Randomized controlled trial	N = 15 healthy male adults aged 20-34, unspecified distribution between treatment and control groups	0.55 g lyophilized royal jelly in enteric-coated capsule ingested orally	Hyperglycemia: Glucose clearance (OGTT)	Improved glucose clearance and decreased plasma insulin, unspecified statistical significance (insufficient information for effect size calculation)
				Insulin resistance: Serum insulin and c-peptide

OGTT: Oral glucose tolerance test; GLUT4: Glucose transporter type 4.