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

Table 2 Human trials examining effects of long-term royal jelly treatment

Ref.	Study design	Subjects	Treatment	Outcome measures	Effectiveness
Khoshpey et al[12]	Randomized double-blind controlled trial	N = 11 females + 12 males aged 20-65 with type 2 diabetes in control group (placebo)	3000 mg royal jelly oral capsules once per day for 8 wk. Control received placebo	Macronutrient intake	No significant change in macronutrient intake
		N = 13 females + 10 males aged 20-65 with type 2 diabetes in treatment group		Hyperglycemia: Fasting blood glucose	Fasting blood glucose significantly reduced in comparison to control group (d = -0.87)
Mobasseri et al[28]	Randomized controlled trial	N = 25 + 25 females with type 2 diabetes aged 30-65 in control and treatment groups	200 mg royal jelly powder prepared in gel form and served with breakfast for 8 wk. Control group received placebo	Plasma triglyceride	Significantly decreased plasma triglyceride in comparison to control (d = -0.476)
Morita et al[29]	Randomized double-blind controlled trial	N = 30 healthy adults 42-83 yr of age in control (placebo)	3000 mg royal jelly in 100 mL liquid daily for 6 mo. Control received placebo identical in appearance	Body weight: BMI	Significantly improved fasting blood glucose (d = -0.9596)
		N = 31 healthy adults 42-83 yr of age in treatment group		Insulin resistance: HOMA-IR	No significant changes in other outcomes of interest
				Hyperglycemia: HbA1c, fasting blood glucose
				Plasma triglyceride
Pourmoradian et al[13]	Human double-blinded randomized clinical trial	N = 23 females aged 30-65 with type 2 diabetes in treatment group	1000 mg lyophilized royal jelly in soft gel form served after breakfast for 8 wk. Control group received placebo soft gel	Body weight: weight scale before and after study period	Significantly decreased body weight within same group, before and after intervention (d = -0.3808)
		N = 22 females aged 30-65 with type 2 diabetes in control group		Macronutrient intake: 24-h recall food questionnaire for 3 d before and after study period	Significantly decreased energy intake within same group, before and after intervention (d = -9.52)
Pourmoradian et al[30]	Human double-blinded randomized controlled trial	N = 21 females aged 30-65 with type 2 diabetes in treatment group	1000 mg lyophilized royal jelly in soft gel form served after breakfast for 8 wk. Control group received placebo soft gel	Plasma insulin	Significantly decreased plasma insulin and HbA1c and insignificantly decreased fasting blood glucose compared to baseline within same group, before and after intervention.
		N = 20 females aged 30-65 with type 2 diabetes in control group		HbA1c	d = 0.016 (HbA1c)
				Hyperglycemia: Fasting blood glucose	d = -0.0785 (plasma insulin)
Shidfar et al[31]	Human double-blinded randomized controlled trial	N = 23 + 23 adults 25-65 yr old with type 2 diabetes in experimental and control (placebo) groups	1000 mg royal jelly in soft gelatin capsules 3 times daily for 8 wk. Control group received placebo identical in appearance to treatment	Fasting blood sugar	Significantly decreased fasting blood levels to more normal range (d = -0.3725)
				Macronutrient intake: 24-h recall diet questionnaire	Did not significantly alter macronutrient intake
				Insulin resistance: HOMA-IR	Significantly decreased HOMA-IR: improved insulin sensitivity (d = -0.79)

RJ: Royal jelly; HOMA-IR: Homeostatic model assessment of insulin resistance; BMI: Body mass index; HbA1c: Hemoglobin A1c.