. 2022 Mar 10;14(6):1170. doi: 10.3390/nu14061170

Table 2.

Selected variables for performing a meta-analysis. The mark “O” denotes the presence of the variable in the protocol of the corresponding study, and “X” if not. The total count represents the number of “O” s.

Categories	Variables	Individual Studies						Total Count
Categories	Variables	# 1	# 2	# 3	# 4	# 5	# 6	Total Count
Chemical Scavenger	α-tocopherol, plasma	O	X	X	O	X	X	2
	γ-tocopherol, plasma	O	X	X	O	X	X	2
	Vitamin C, plasma	O	O	X	O	O	X	4
	Vitamin B₆, plasma	O	O	X	O	O	X	4
	Vitamin B₁₂, plasma	O	O	X	O	O	X	4
	Folate, plasma	X	O	O	O	O	X	4
	Lutein, plasma	O	O	X	X	X	O	3
	Zeaxanthin, plasma	X	O	X	X	X	O	2
	α-carotene, plasma	O	X	X	X	X	O	2
	β-carotene, plasma	O	O	O	O	O	O	6
	Lycopene, plasma	O	X	X	X	X	O	2
Oxidative Damage	Homocysteine, plasma	O	O	O	O	O	X	5
	CRP ^†, plasma	O	X	O	O	X	O	4
	MDA ^‡, plasma	X	X	O	X	X	O	2
	Ox-LDL ^§, plasma	X	X	O	X	O	O	3
	Comet assay, PBMC	O	X	O	X	X	O	3
	Comet assay, PBMC H₂O₂ challenge	X	X	O	X	X	O	2
	8-OHdG ^#, urine	O	X	X	X	X	O	2
QOL	Short Form 36 questionnaire	O	X	O	X	X	X	2

^† CRP: C-reactive protein, ^‡ MDA: malondialdehyde, ^§ Ox-LDL: oxidized low-density lipoprotein, ^¶ PBMC: peripheral blood mononuclear cells, ^# 8-OHdG: 8-hydroxy-2′-deoxyguanosine.