饮酒驱寒？这可能只是你的错觉……

2022-12-29 07:12

冬日里天寒地冻，一些人喜欢在此时小酌两杯，暖身御寒，颇有文人雅士之风。但这种方法真的合理吗？

真相是：喝酒不仅不能驱寒，甚至更容易导致发冷。

喝完酒后，脸颊泛红，微微出汗，确实给人一种暖和起来的感觉。然而，喝酒真能暖身吗？

The characteristic flushed cheeks and occasional sheen of sweat on someone who’s been imbibing certainly suggest that alcohol has an effect on body temperature, but when you drink an alcoholic beverage, does it really warm you up?

sheen: /ʃiːn/ n. 光泽

答案是否定的。实际上，体温并没有变化，它只是在重新分配热量。

酒精会引起血管扩张，尤其是皮肤下的毛细血管。喝酒后，输送到皮肤表面的血液量增加，从而让人感受到热量。也正是因为血管的扩张，所以人们喝酒后会面色潮红。

Alcohol is a vasodilator. It causes your blood vessels to dilate, particularly the capillaries just under the surface of your skin. When you have a drink, the volume of blood brought to the skin's surface increases, making you feel warm. That dilation is why slightly or exceedingly intoxicated people look flushed.

vasodilator: /ˌveɪzəʊˈdaɪleɪtə/ n. 血管舒张剂
capillary: /kəˈpɪləri/ n. 毛细血管

图源：Gettys Images

但人体面对低温气候时，会天然地选择收缩血管，减少流向皮肤的血液，以保持身体的核心体温。而喝酒带来的血管扩张却阻碍了人体自然的防御措施。

This overrides one of your body’s defenses against cold temperatures: Constricting your blood vessels, thereby minimizing blood flow to your skin in order to keep your core body temperature up.

在冬天小酌一杯，或许会因为额外输送来的血液而让皮肤变暖，达到驱寒的目的，但冷空气会迅速使血液冷却下来。

Someone enjoying a drink in the cold may feel warmer from the extra blood warming his skin, but that blood will rapidly cool thanks to the chill in the air.

图源：Shutterstock

当热量挥发后，毛孔张开，会更容易受到寒冷的侵袭。

另外，喝酒后，皮肤感受到热量，会给大脑发送错误信息：“我现在很热”，从而做出降温的举措。血液涌向皮肤，带来热量，让人开始流汗，更进一步降低核心温度。

The warmth caused by blood rushing to the skin will also make him sweat, decreasing his core temperature even further.

加上酒精对人的认知能力的影响，情况会变得更糟。因为皮肤仍然保持着温度，喝酒的人甚至根本意识不到自己的体温正在急速下降，这让在冬天饮酒变得更加危险。

Compounded with the cognitive effects of alcohol, serious complications can arise. The rapid drop often occurs without the drinker realizing it, because his skin will still feel fairly warm, which makes it doubly dangerous to drink alcohol in extremely cold weather.

除此之外，酒精还阻碍了身体尝试获取热量的另一个途径——发抖。

图源：Gettys Images

发抖会让肌肉在短时间内不断收紧和放松，相较于待着一动不动，这会促使肌肉运动而产生热量，让人感到温暖。

When you shiver, your muscles tighten and relax over and over again in a short amount of time. The energy that it takes to make your muscles do that gives off heat, keeping your body a little warmer than it would otherwise be.

在冬天喝酒则会降低身体的调节能力，抑制颤抖的本能，让人在寒冷时无法保持温暖。

But, drinking alcohol in chilly weather reduces the body’s ability and tendency to shiver, taking away yet another method your body uses to help keep warm when it is cold.