Table 2 Human studies of MSG without food

Geha RS (2000) [11]

200 ml of citrus-flavored beverage

[Protocol A] 5 g MSG and placebo (0 g MSG) on separate day (day 1 & 2)

130 self-reported MSG-reactive volunteers (female:84, male:46)

[Frequency] Placebo: 0.28 5 g MSG: 0.54 (P < 0.005)**

Significant difference

Yang WH (1997) [12]

200 ml of a strongly citrus-tasting beverage sweetened by sucrose.

(1) 5 g MSG or placebo(0 g MSG) (empty stomach)

61 subjects self-identified MSG-sensitive people (male:15, white:59, black:1, oriental:1)

Placebo: 24 5 g MSG: 23

No difference

(2) placebo(0 g MSG, no substitute), 1.25, 2.5, 5 g MSG in random sequence.

36 subjects Subjects who responded to either of MSG or placebo in study(1) (not both or not neither). No indication about gender.

Placebo: 9 1.25 g MSG: 11 2.5 g MSG:16(P < 0.04)* 5 g MSG: 18(P < 0.023)*

1.25 g: no difference 2.5, 5 g:significant difference

Shimada A (2013) [13]

400 ml Sugar-free lemon soda

MSG (150 mg/kg = 9 g/60 kg) for 5 consecutive days (in the week) and NaCl (24 mg/kg) in the other week in randomized sequence.

14 healthy adults (female:9, male:5)

Placebo: 2 150 mg/kg MSG(=9 g/60 kg): 8* (P = 0.041)

Significant difference

Baad-Hansen L (2010) [14]

400 ml Sugar-free soda

NaCl (24 mg/kg), MSG (75 or 150 mg/kg =6 or 9 g/60 kg) in random sequence.

14 healthy men

Placebo: 0 75 mg/kg MSG(=4.5 g/60 kg): 27* (P = 0.045, vs placebo and 150 mg/kg MSG) 150 mg/kg MSG (=9 g/60 kg): 7

75 mg/kg: significant difference 150 mg/kg: no difference

Rosenblum I (1971) [15]

100 ml tap water or chicken stock

15 h after the last meal. (Group I–IV)5 g MSG in tap water(49 subjects) or chicken stock(49 sub.). (Group V)1.7 g NaCl in chicken stock(24 sub.) (Group VI) chicken stock(25 sub.).

99 male volunteers, 21–59 years old.

[Frequency] Placebo(Group V, VI):8 % 5 g MSG(Group I–IV):17 %

No difference

100 ml chicken stock

(Group VII) 8 g(6 sub.) MSG in chicken stock, 2.8 g NaCl in chicken stock(5 sub.). (Group VIII) 12 g MSG in chicken stock(5 sub.), 4.2 g NaCl in chicken stock (5 sub).

11 people Chosen from the original 99 subjects, based on the results of the test above. One-half reported multiple complaints on the questionnaire while the other reported no complaints.

Placebo(NaCl2.8 g):2 8 g MSG(VII):3 Placebo(NaCl4.2 g):0 12 g MSG(VIII):2

No difference