Cornelis Marilyn C, El-Sohemy Ahmed, Campos Hannia
Department of Nutritional Sciences, University of Toronto, Canada.
Am J Clin Nutr. 2007 Sep;86(3):752-8. doi: 10.1093/ajcn/86.3.752.
Cruciferous vegetables are a major dietary source of isothiocyanates that may protect against coronary heart disease. Isothiocyanates induce glutathione S-transferases (GSTs), polymorphic genes that code for enzymes that conjugate isothiocyanates, as well as mutagens and reactive oxygen species, to make them more readily excretable.
The objective of the study was to determine whether GST genotypes modify the association between cruciferous vegetable intake and the risk of myocardial infarction (MI).
Cases (n = 2042) with a first acute nonfatal MI and population-based controls (n = 2042) living in Costa Rica, who were matched for age, sex, and area of residence, were genotyped for a deletion polymorphism in GSTM1 and GSTT1 and an Ile105Val substitution in GSTP1. Cruciferous vegetable intake and smoking status were determined by questionnaire. Odds ratios (ORs) and 95% CIs for MI were estimated by unconditional logistic regression.
Compared with the lowest tertile of cruciferous vegetable intake, the highest tertile was associated with a lower risk of MI among persons with the functional GSTT11 allele (OR: 0.70; 95% CI: 0.58, 0.84) but not among those with the GSTT100 genotype (OR: 1.23; 95% CI: 0.83, 1.82) (P = 0.006 for interaction). This protective effect among those with the GSTT11 allele was greater for current smokers (OR: 0.54; 95% CI: 0.36, 0.79) than for nonsmokers. GSTP1 and GSTM1 did not modify the association between cruciferous vegetable intake and MI.
Consumption of cruciferous vegetables was associated with a lower risk of MI among those with a functional GSTT1*1 allele, which suggests that compounds that are detoxified by this enzyme contribute to the risk of MI.
十字花科蔬菜是异硫氰酸盐的主要饮食来源，而异硫氰酸盐可能预防冠心病。异硫氰酸盐可诱导谷胱甘肽S-转移酶（GSTs），这是一类多态性基因，编码可使异硫氰酸盐以及诱变剂和活性氧发生共轭反应的酶，从而使其更易于排泄。
本研究旨在确定GST基因型是否会改变十字花科蔬菜摄入量与心肌梗死（MI）风险之间的关联。
对居住在哥斯达黎加的2042例首次发生急性非致命性MI的病例和2042例基于人群的对照进行基因分型，这些对照在年龄、性别和居住地区方面进行了匹配，检测GSTM1和GSTT1基因的缺失多态性以及GSTP1基因第105位密码子异亮氨酸（Ile）到缬氨酸（Val）的替换。通过问卷调查确定十字花科蔬菜摄入量和吸烟状况。采用非条件logistic回归估计MI的比值比（OR）和95%可信区间（CI）。
与十字花科蔬菜摄入量最低的三分位数相比，摄入量最高的三分位数与携带功能性GSTT11等位基因者发生MI的风险较低相关（OR：0.70；95%CI：0.58，0.84），而与携带GSTT100基因型者无关（OR：1.23；95%CI：0.83，1.82）（交互作用P = 0.006）。对于当前吸烟者，携带GSTT11等位基因者的这种保护作用（OR：0.54；95%CI：0.36，0.79）大于不吸烟者。GSTP1和GSTM1未改变十字花科蔬菜摄入量与MI之间的关联。
对于携带功能性GSTT1*1等位基因者，食用十字花科蔬菜与较低的MI风险相关，这表明由该酶解毒的化合物与MI风险有关。
