Table 11.

Clinical studies regarding the impact of MSG consumption on headache

Study design	MSG vehicle	Number of participants	Protocol	Results	Author
Double-blinded, placebo-controlled, crossover study	400 mL sugar-free soda	14 healthy participants	Volunteers received (a) MSG (75 or 150 mg/kg) or (b) NaCl (24 mg/kg, placebo) in three separate sessions	Significant increase in the incidence of headache (p<0.05) for MSG group 75 mg/kg, but not for MSG 150 mg/kg. Systolic BP was elevated in the high MSG session.	(Baad-Hansen et al., 2009)
Double-blinded, placebo-controlled, crossover study	400 mL sugar-free lemon soda	14 healthy participants	Volunteers received (a) MSG 5g or (b) NaCl (24 mg/kg), in two distinct 5-days sessions.	Significant increase in the incidence of headache (p<0.05) for MSG group vs placebo.	(Shimada et al., 2016)
Multicenter, multiphase, double-blind, placebo-controlled crossover study	200 mL citrus soda	130 self-reported MSG-reactive participants	Volunteers received (a) MSG 5 g one day or (b) no MSG (placebo) the following day	Significant increase in the frequency of headache (p<0.05) for MSG group vs placebo.	(Geha et al., 2000b)
Double-blinded, placebo-controlled, crossover study	200 mL citrus-tasting soda	36 participants	Volunteers received (a) MSG 1.25 g, (b) MSG 2.5 g, (c) MSG 5 g or (d) placebo (no MSG), in four distinct 1-day sessions.	Significant increase in the incidence of headache for MSG 2.5 g and 5 g vs placebo (p<0.05), not for MSG 1.25 g.	(Yang et al., 1997)
Randomized double-blind, placebo controlled crossover study	Capsule	71 participants	On first 3 days, capsules containing (a) 1.5 g MSG, (b) 3 g MSG or (c) placebo (gelatin powder) immediately followed by breakfast	No correlation between MSG consumption and headache.	(Tarasoff & Kelly, 1993)
	Soft drink		The following 2 days, 300 mL soda containing (1\a) 3.15 g MSG or (b) placebo.	No correlation between MSG consumption and headache.