HMG：喝咖啡有助于不吸烟人群降血压

近日，瑞士洛桑沃州大学的一项研究结果显示，常喝咖啡对于降低血压可能有积极作用，但吸烟会抵消这种作用。

研究人员在新一期英国学术期刊《人类分子遗传学》（Human Molecular Genetics）上发表报告说，他们调查了1.6万人的血压、喝咖啡习惯和体内一种酶的状况，发现三者之间存在关联。

研究显示，编码CYP1A2的酶在肝脏分解咖啡因的过程中发挥决定性作用，体内这种酶较活跃的人大多常喝咖啡，而他们的血压普遍低于这种酶不太活跃者。

此前有研究认为，过度摄取咖啡因可导致血压升高和失眠，但这份新报告的第一作者伊德里斯·盖苏说，虽然喝咖啡短时间内会增高血压，但长期坚持会产生相反结果。这与慢跑对血压的作用相似——慢跑时血压升高，但坚持慢跑锻炼可预防心血管病。

这项研究还发现，咖啡的降血压作用仅适用于不吸烟的人，因为吸烟会影响CYP1A2酶的活动，从而抵消咖啡的这一有益作用。

拓展阅读：

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喝咖啡能降低2型糖尿病发病风险吗？

咖啡有助于预防头颈部癌

美发现咖啡降低患皮肤癌风险

原始文献：

doi:10.1093/hmg/dds137
PMC:
PMID:

Caffeine intake and CYP1A2 variants associated with high caffeine intake protect non-smokers from hypertension

Idris Guessous, Maria Dobrinas, Zoltán Kutalik, Menno Pruijm, Georg Ehret, Marc Maillard, Sven Bergmann5, Jacques S. Beckmann, Daniele Cusi1, Federica Rizzi1, Franco Cappuccio1, Jacques Cornuz, Fred Paccaud, Vincent Mooser, Jean-Michel Gaspoz, Gérard Waeber, Michel Burnier, Peter Vollenweider, Chin B Eap and Murielle Bochud1

The 15q24.1 locus, including CYP1A2, is associated with blood pressure (BP). The CYP1A2 rs762551 C allele is associated with lower CYP1A2 enzyme activity. CYP1A2 metabolizes caffeine and is induced by smoking. The association of caffeine consumption with hypertension remains controversial. We explored the effects of CYP1A2 variants and CYP1A2 enzyme activity on BP, focusing on caffeine as the potential mediator of CYP1A2 effects. Four observational (n = 16 719) and one quasi-experimental studies (n = 106) including European adults were conducted. Outcome measures were BP, caffeine intake, CYP1A2 activity and polymorphisms rs762551, rs1133323 and rs1378942. CYP1A2 variants were associated with hypertension in non-smokers, but not in smokers (CYP1A2-smoking interaction P = 0.01). Odds ratios (95% CIs) for hypertension for rs762551 CC, CA and AA genotypes were 1 (reference), 0.78 (0.59–1.02) and 0.66 (0.50–0.86), respectively, P = 0.004. Results were similar for the other variants. Higher CYP1A2 activity was linearly associated with lower BP after quitting smoking (P = 0.049 and P = 0.02 for systolic and diastolic BP, respectively), but not while smoking. In non-smokers, the CYP1A2 variants were associated with higher reported caffeine intake, which in turn was associated with lower odds of hypertension and lower BP (P = 0.01). In Mendelian randomization analyses using rs1133323 as instrument, each cup of caffeinated beverage was negatively associated with systolic BP [?9.57 (?16.22, ?2.91) mmHg]. The associations of CYP1A2 variants with BP were modified by reported caffeine intake. These observational and quasi-experimental results strongly support a causal role of CYP1A2 in BP control via caffeine intake.