VOA标准英语2011--Study: Cutting Salt Might Increase Heart Risks

Study: Cutting Salt Might Increase Heart Risks

 

A new study casts doubt on the merits of reducing salt in our diet. The researchers found that a modest lowering of blood pressure may be offset¹ by other less desirable effects of a low-sodium² diet.

For years it's been part of accepted medical wisdom: reducing salt in your diet will lower your blood pressure, which will lower your risk of heart attack and stroke.

But according to Danish researcher Niels Graudal of Copenhagen University Hospital, the effect of a reduced-salt diet is less dramatic than you might think.

"We found that in normal persons with normal blood pressure, the effects on the blood pressure were surprisingly small. In patients with hypertension, the effect was somewhat bigger: the decrease was about 3.5 percent," he says.

Graudal mathematically combined the results of 167 previous studies to come up with his results. The people in the studies were largely European and North American, although Asians and blacks on low-sodium diets showed a somewhat larger reduction in their blood pressure.

A recent study finds people on low-sodium diets have higher levels of cholesterol3, which is associated with an increased risk of heart disease.

Even a modest reduction for people with high blood pressure is probably a good thing, but the study also found that people on a low-sodium diet had higher levels of cholesterol, which is associated with an increased risk of heart disease.

Graudal says the body's natural salt-regulation system was also affected⁴ by a low-sodium diet. "And we saw that when you reduce the sodium intake⁵, the hormone⁶ system was activated⁷, which means that the body obviously felt that there was a danger that the amount of salt in the body could become too low."

It might be more helpful to look directly for a link between salt consumption and heart disease or death, but Graudal says very few studies have tried to do that.

"It would be very difficult to make a randomized, a big randomized study and keep people on special diets for many years," he explains. "Practically that would be very, very difficult."

Graudal cautions that his study should not be interpreted as a license⁸ to eat as much salt as you want. He says it just confirms that a moderate amount of salt in a normal diet is probably not harmful, and reducing salt intake has both positive and negative effects that might not help reduce the risk of heart attack and stroke.

His paper reviewing previous studies on the impact of low-sodium diets is published in the American Journal of Hypertension.

1 offset   

n.分支，补偿；v.抵消，补偿

参考例句：

• Their wage increases would be offset by higher prices.他们增加的工资会被物价上涨所抵消。
• He put up his prices to offset the increased cost of materials.他提高了售价以补偿材料成本的增加。

2 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

3 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

4 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

5 intake   

n.吸入，纳入；进气口，入口

参考例句：

• Reduce your salt intake.减少盐的摄入量。
• There was a horrified intake of breath from every child.所有的孩子都害怕地倒抽了一口凉气。

6 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

7 activated   

adj. 激活的 动词activate的过去式和过去分词

参考例句：

• The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。

8 license   

n.执照，许可证，特许；v.许可，特许

参考例句：

• The foreign guest has a license on the person.这个外国客人随身携带执照。
• The driver was arrested for having false license plates on his car.司机由于使用假车牌而被捕。