Association between Circulating Antioxidants and Longevity: Insight from Mendelian Randomization Study

Table 1

Description of data sources of the genetic instruments used for circulating antioxidants in the Mendelian randomization study.

Antioxidant	Sample size	No. of SNPs	Unit	Ancestry	value	Variance (%)^†	Overlap^§	PMID
Absolute circulating antioxidants
Ascorbate	15,087	10	μmol/l	European	5-08	1.87%	None	33203707
Lycopene	441	5	μg/dl	European	5-08	30.1%	None	26861389
Selenium	4,162	4	μg/g in natural log-transformed scale	Primarily European	5-08	5.9%	None	25343990
β-Carotene	2,344	3	μg/l in natural log-transformed scale	European	5-08	9.0%	None	23134893
Retinol	5,006	2	μg/l in natural log-transformed scale	European	5-08	2.3%	None	21878437
Circulating antioxidant metabolites
Ascorbate	2,063	14	Log10-transformed metabolites	European	1-05	18.6%	None	24816252
α-Tocopherol	7,276	11	Log10-transformed metabolites	European	1-05	3.3%	None	24816252
γ-Tocopherol	5,822	13	Log10-transformed metabolites	European	1-05	15.0%	None	24816252
Retinol	1,957	24	Log10-transformed metabolites	European	1-05	4.8%	None	28263315

Study population contains both Europeans and African-American participants. ^†Explained variance for circulating antioxidant metabolites were as reported in GWASs or calculated using the formula of assuming no genetic interactions, where MAF denotes the minor allele frequency and denotes the effect of SNPs on the antioxidant metabolites. ^§The estimated overlap of the longevity GWAS with the exposure GWASs. Abbreviation: SNPs: single-nucleotide polymorphisms.