Table 1.

Summary of the cited clinical studies and meta-analyses involving the use of d-chiro-inositol, flaxseed, sweet potato, and banaba.

Author	Intervention	Study Design	Population	Dosage/Duration	Outcomes	Results
Cheang et al. [64]	DCI supplementation	RCT with placebo	11 women (18–40 y) with PCOS	1200 mg twice daily for 6 weeks	Hormones, plasma DCI, DCI-IPG release, insulin sensitivity	Significant relationship between DCI-IPG release and insulin sensitivity
Nestler et al. [65]	DCI supplementation	RCT with placebo	44 obese women (18–40 y) with PCOS	1200 mg/day for 6 to 8 weeks	Hormones, lipid profiles, BP, plasma insulin	Increase of the action of insulin, improvement of ovulatory function and decrease androgens, BP, and TG
Genazzani et al. [66]	DCI supplementation	Intervention trial	22 obese women (age not reported) with PCOS	500 mg/day for 12 weeks	Hormones and plasma insulin	Improvement of hormonal pattern, especially LH and FSH, and restores insulin sensitivity
De Leo et al. [68].	DCI supplementation	Intervention trial	20 women (age not reported) with PCOS	500 mg twice daily for12 weeks	Oxidative stress on follicular fluids	Reduction of the oxidation of thiol groups
Haidari et al. [69]	Flaxseed powder supplementation	Open label RCT	41 patients (18–45 y) with PCOS	30 g/day for 12 weeks	Anthropometric and biochemical parameters	Reduction in body weight, HOMA-IR, TG, hs-CRP and leptin, and increase in QUIKI, and HDL
Pan et al. [70]	Supplementation with flaxseed and its derivatives	Meta-analysis of 28 RCTs	1539 subjects (age not reported) with HC, T2D, or healthy	Median dose 38 g; median duration 8.5 weeks	Blood lipid concentrations	Reduction in total and LDL-cholesterol
Mohammadi-Sartang et al. [71]	Supplementation with whole flaxseed, flaxseed oil, and lignan extract	Meta-analysis of 25 RCTs	2080 subjects (mean age from 29.4 to 67.6 y) with PCOS, HC, T2D, CVD, MetS, obesity, or healthy	Whole flaxseed from 10–60 g ALA from 1 to 15 g; Lignans from 21 to 600 mg Duration from 2 to 48 weeks	Glucose control and insulin sensitivity	Reduction in blood glucose, insulin levels, and increase in QUIKI
Ludvik et al. [72]	Supplementation with sweet potato	RCT with Placebo	61 patients (mean age 57.2 y) with T2D	4 g/day for 20 weeks	Insulin sensitivity, T2D parameters, lipids, adiponectin, hs-CRP, and fibrinogen	Improvement in HbA1c, TG, adiponectin, fibrinogen, and insulin sensitivity
Shih et al. [73]	Supplementation with sweet potato	RCT with no placebo	56 overweight (mean age 38.7 y) participants	132 g/day for 8 weeks	Anthropometric and biochemical parameters	Improvement in HbA1c, and reduction in BMI
Judy et al. [74]	Supplementation with an extract from banaba	RCT with no placebo	10 subjects (55–70 y) With T2D	16, 32 and 48 mg/day for 2 weeks	Blood glucose levels	Reduction in blood glucose levels
Tsuchibe et al. [75]	Supplementation with corosolic acid extracted from banaba	RCT with no placebo	12 healthy subjects (mean age 57.7 y)	10 mg/day for 2 weeks	Postprandial blood glucose and anthropometric parameters	Inhibitory effect on postprandial blood glucose. Reduction in BMI.
Fukushima et al. [76]	Supplementation with corosolic acid extracted from banaba	double-blind and cross-over RCT	31 subjects (mean age 51.6 y) with T2D and impaired glucose tolerance	10 mg; different time points	Fasting plasma glucose	Lowering effect on post-challenge plasma glucose levels

Abbreviation: D-chiro-inositol, DCI. Randomized controlled trial, RCT. Polycystic ovary syndrome, PCOS. Inositolphosphoglycan, IPG. Blood pressure, BP. Triglycerides, TG. Luteinizing hormone, LH. Follicle-stimulating hormone, FSH. Homeostatic model assessment of insulin resistance, HOMA-IR. High-sensitivity C-Reactive Protein, hs-CRP. Quantitative Insulin-Sensitivity Check Index, QUIKI. High Density Lipoprotein, HDL. Hypercholesterolemia, HC. Type 2 diabetes, T2D. Low-density lipoprotein, LDL. Cardiovascular disease, CVD. Metabolic syndrome, MetS. a-linolenic acid, ALA. Glycated haemoglobin, HbA1c. Body mass index, BMI.