Middle-aged men who ate seven or more eggs a week had a higher risk of earlier death, U.S. researchers reported on Wednesday.

Men with diabetes who ate any eggs at all raised their risk of death during a 20-year period studied, according to the study published in the American Journal of Clinical Nutrition.

The study adds to an ever-growing body of evidence, much of it contradictory, about how safe eggs are to eat. It did not examine what about the eggs might affect the risk of death.

Men without diabetes could eat up to six eggs a week with no extra risk of death, Dr. Luc Djousse and Dr. J. Michael Gaziano of Brigham and Women's Hospital and Harvard Medical School found.

"Whereas egg consumption of up to six eggs a week was not associated with the risk of all-cause mortality, consumption of (seven or more) eggs a week was associated with a 23 percent greater risk of death," they wrote.

"However, among male physicians with diabetes, any egg consumption is associated with a greater risk of all-cause mortality, and there was suggestive evidence for a greater risk of MI (heart attack) and stroke."

They urged more study in the general population.

Neither 'good' nor 'bad'
Eggs are rich in cholesterol, which in high amounts can clog arteries and raise the risk of heart attack and stroke.

One expert on nutrition and heart disease said the study suggests middle-aged men, at least, should watch how many eggs they eat.

"More egg on our faces? It's really hard to say at this point, but it still seems, if you're a middle-aged male physician and enjoy eggs more than once a day, that having some of the egg left on your face may be better than having it go down your gullet," said Dr. Robert Eckel of the University of Colorado and a former president of the American Heart Association.

"But, remember: eggs are like all other foods — they are neither 'good' nor 'bad,' and they can be part of an overall heart-healthy diet," Eckel wrote in a commentary.

More likely to drink, smoke
The Harvard team studied 21,327 men taking part in the much larger Physicians' Health Study, which has been watching doctors since 1981 who have agreed to report regularly on their health and lifestyle habits.

Over 20 years, 1,550 of the men had heart attacks, 1,342 had strokes, and more than 5,000 died.

"Egg consumption was not associated with (heart attack) or stroke," the researchers wrote.

But the men who ate seven eggs a week or more were 23 percent more likely to have died during the 20-year period.

Diabetic men who ate any eggs at all were twice as likely to die in the 20 years.

Men who ate the most eggs also were older, fatter, ate more vegetables but less breakfast cereal, and were more likely to drink alcohol, smoke and less likely to exercise — all factors that can affect the risk of heart attack and death.

美国研究人员周三报告说，一周吃七个或者更多鸡蛋的中年男子有更高的提早死亡的风险。

根据刊登在美国临床营养学杂志上的这份研究报告，在长达20年的研究期间里，患糖尿病的男性吃任何鸡蛋都无例外地增加了自己的死亡风险。

这份研究报告加入到不断增加的关于如何安全吃鸡蛋的证据材料中，其中很大一部分是矛盾的。但是它没有研究鸡蛋怎么可能影响死亡风险。

布里格姆与妇女医院和哈佛医学院的医生Luc Djousse和医生 J. Michael Gaziano发现，无糖尿病的男子可以一周吃六个鸡蛋而没有额外的死亡风险。

“一周的鸡蛋消费量达到6个鸡蛋与所有原因死亡率的风险没有关联，而一周消费（ 7个或更多）鸡蛋则伴随有 23％ 以上的死亡风险，”他们写道。

“然而，在患糖尿病得男性医生中，任何鸡蛋消费都与所有原因死亡率的更大风险相关联，并且有更大的心肌梗塞（心脏病发作）和中风风险的术前诊断证据。”

他们呼吁在一般人群中进行更多的研究。

鸡蛋既不‘好'，也不‘坏'

鸡蛋富含胆固醇，而高量的胆固醇可能阻塞动脉并且增加心脏病发作和中风的风险。

一位营养学与心脏病方面的专家说，这项研究表明，中年男性至少应该注意他们吃多少个鸡蛋。

“更多的鸡蛋在我们面前？在这一点上实在很难说，但是它仍然似乎是，如果你是一位中年男性医师，并且一天享用鸡蛋一次以上，则让这个鸡蛋留一些在你的面前可能比让它下到你的食道里要好一些，”科罗拉多大学的博士和美国心脏协会的前会长Robert Eckel说。

“但是，请记住：鸡蛋像所有其它的食品一样——它们既不是‘好’的 ，也不是‘坏’的 ，而且它们可能是整个有益心脏健康的饮食的一部分，”Eckel在一篇评论中写道。

可能是更多地饮酒、吸烟

哈佛大学的专家小组对参加了大得多的医师健康研究的21,327名男子进行了研究，他们自1981年以来看医生，同意定期汇报他们的健康情况和生活习惯。

20多年过去， 1,550名男子曾经心脏病发作， 1,342名曾经中风，并且有5,000 多人死亡。

“鸡蛋消费量与（心脏病发作）或中风无明显关联，”研究人员写道。

但是，一周吃掉7个或者更多鸡蛋的男子是23％ 更多的可能在20年期限内死亡。
吃任何蛋类的糖尿病男子是两倍地可能会在20年内死去。

男人吃最多的鸡蛋并且更老一些、更胖一些，吃较多的蔬菜但是较少的早餐谷类食品，以及可能更多地饮酒、吸烟并且可能较少地运动——所有这些都是可能影响心脏病发作和死亡风险的因素。