The effects are heightened in men who believe that the woman in question is "out of their league".

Cortisol is produced by the body under physical or psychological stress and has been linked to heart disease.

Researchers tested 84 male students by asking each one to sit in a room and solve a Sudoku puzzle. Two strangers, one male and one female, were also in the room.

When the female stranger left the room and the two men remained sitting together, the volunteer's stress levels did not rise. However, when the volunteer was left alone with the female stranger, his cortisol levels rose.

The researchers concluded: "In this study we considered that for most men the presence of an attractive woman may induce the perception that there is an opportunity for courtship.

"While some men might avoid attractive women since they think they are 'out of their league', the majority would respond with apprehension and a concurrent hormonal response.

"This study showed that male cortisol levels increased after exposure to a five-minute short social contact with a young, attractive woman."

Cortisol can have a positive effect in small doses, improving alertness and well-being. However, chronically elevated cortisol levels can worsen medical conditions such as heart disease, diabetes, hypertension and impotency.

科研人员日前发现，与美女会面可能有害健康。

尤其是当男性遇到他们觉得“遥不可及”的美女时，这种影响会增强。

人的身体在生理或心理的压力下会产生一种名叫皮质醇的物质，这种物质与心脏病的发生有关。

研究人员对84名男性学生进行了测试，让他们每人坐在一个房间里做一道数独题。房间里还同时安排了一男一女两个陌生人。

当陌生女性离开房间，屋内剩下两名男性时，研究对象的压力水平没有升高。而当调查对象与陌生女性单独共处一室时，他的皮质醇水平便出现了升高。

研究人员得出结论：“在这项研究中我们发现，对于大多数男性来说，美女的出现会让他们产生这样一种想法，即存在求爱的机会。

“尽管一些男性会因为觉得美女‘遥不可及’而避免与她们接触，但大多数男性的反应还是比较积极，同时荷尔蒙水平也会发生变化。

“研究显示，当男性与一个年轻漂亮的女性短暂接触五分钟后，皮质醇水平就会升高。”

少量的皮质醇能给人体带来一些积极影响，如提高机敏度，增进健康。然而，皮质醇水平长期过高会加重心脏病、糖尿病、高血压和性无能等疾病患者的病情。