Table 1.

Clinical evidence of dietary polyphenols in the management of peptic ulcer

Polyphenol	Preparations		Study design	Disease	No. of patients	Treatment duration	Outcomes	Level of evidence1	Ref.
	Treatment group	Control group
Curcumin	Turmeric 250 mg, four times per day	Liquid antacid: aluminum hydroxide (333 g) and magnesium hydroxide (33.3 g) per 1000 mL (30 mL, four times per day	Randomized controlled clinical	Benign gastric ulcers	60	12 wk	Both antacid drug and turmeric significantly reduced the formation of gastric ulcer. The former was more effective in reducing the ulcers	1b	Kositchaiwat et al[55]
Curcumin	Capsule-filled turmeric 3 g/d	-	Uncontrolled clinical trial	Peptic ulcer	54	4 wk	12 (48%) of patients showed remission after 4 wk, 18 of patients after 8 wk of treatment and 19 of patients after 12 wk. There was no significant alteration in hematological parameters, liver, or renal functions after treatment	4	Prucksunand et al[56]
Curcumin	Turmeric tablet (40 mg curcumin)	Omeprazole (20 mg), amoxicillin (1 g), metronidazole (800 mg), twice a day for 1 wk	Randomized controlled trial	Chronic gastritis with H. pylori infection	36	4 wk	The eradication rate of H. pylori in curcumin group was 5.9% while in control group was 78.9%. IL-8 mRNA expression in control group reduced significantly in comparison with before trial, while curcumin had no effect on IL-8	1b	Koosirirat et al[57]
Curcumin	Curcumin (30 mg), bovine lactoferrin (100 mg), N-acetylcysteine (600 mg), and pantoprazole (20 mg), twice daily	-	Uncontrolled clinical trial	Peptic ulcer	25	7 d	12% of patients showed eradication of H. pylori infection, overall severity of gastrointestinal symptoms was significantly decreased after treatment in comparison with baseline (P < 0.001). Serum pepsinogens were significantly reduced after treatment in comparison with baseline (P < 0.05)	4	Di Mario et al[58]
Green tea	More than 1 d in week	-	Cohort study	Peptic ulcer	150	-	The incidence of H. pylori infection was lower in patients consuming green tea (45.2%) compared with the other patients (64.8%)	4	Boyanova et al[87]

¹Level of evidence was calculated based on Oxford Centre for Evidence-based Medicine - Levels of Evidence (March 2009).