Nitrosamine and related food intake and gastric and oesophageal cancer risk: A systematic review of the epidemiological evidence

Table 1 Overall quantification of epidemiological studies on nitrosamines and related food intake and gastric and oesophageal cancer risk

	Gastric cancer		Oesophageal cancer
	n Studies		n Studies
	(n positive association)		(n positive association)
	[n SS]		[n SS]
Dietary exposure	Case-control	Cohort	Case-control	Cohort
Nitrites	7 (5) [3]	2 (1) [0]	2 (1) [0]
Nitrosamines	5 (4) [3]	1 (0) [0]	1 (1) [0]
Meat	16 (11) [2]	3 (2) [1]	18 (11) [6]	2 (1) [1]
Processed meat	14 (10) [4]	6 (2) [2]	9 (8) [5]
Preserved fish	7 (6) [4]	5 (1) [0]	2 (2) [1]
Preserved vegetables	6 (5) [5]	3 (3) [0]	5 (2) [0]	2 (0)
Smoked foods	3 (3) [3]
Beer	7 (6) [1]

SS: Statistically significant.