VOA标准英语2012--Obesity Linked to Brain Damage

Obesity¹ Linked to Brain Damage

 

Researchers are beginning to understand why lasting² weight loss is so hard. They believe it has to do with damage to the part of the brain that’s involved in weight control.

If obese³ people stop overeating, switch to a healthful diet and start exercising, they lose weight. However, they may quickly gain it back again. The reason, say researchers, is not a lack of willpower but injury to brain cells, or neurons, in the hypothalamus - a structure deep in the brain that helps control a number of body functions including appetite and weight.

The notion that brain damage might play a role in body weight is not a new one, according to Michael Schwartz of the Diabetes⁴ and Obesity Center at the University of Washington in Seattle.

Scientists have known for about five years that the hypothalamus of overweight animals - including humans - displays inflammation, a typical reaction to injury.

But researchers, led by Schwartz, wanted to determine the role hypothalamus injury plays in obesity, and they had several questions they wanted to answer:

“Is it simply a consequence of becoming obese or does it occur before the obesity occurs?" says Schwartz. "And what could be driving that response? What is causing the inflammatory response and could that have something to do with the obesity itself?”

Scientists have found that injury to brain cells in the hypothalamus plays a role in obesity.

Schwartz’s team put laboratory mice and rats on a high-fat diet to make them gain weight. When they looked for evidence of inflammation in their brains, they made a startling discovery.

“We were frankly⁵ shocked to realize the inflammation became apparent within 24 hours of the switch in diet,” says Schwartz.

The researchers also saw evidence of a strong and rapid neuro-protective response, as cells were activated⁶ to repair the damaged neurons. But the animals were kept on the high-fat diet for nine months and the inflammation eventually returned.

The key message, according to Schwartz, is that it’s not the fault of people who try and fail repeatedly to lose weight through dieting.

“Our data would point to a more structural⁷, biological basis for why it is difficult to keep weight off," he says. "It has to do with damage to the brain area that is responsible for controlling body weight.”

Schwartz says that also explains why drugs are not effective at helping⁸ people achieve lasting weight loss. The compounds currently available do not target what appears to be the underlying⁹ cause of obesity.

1 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。

2 lasting   

adj.永久的，永恒的；vbl.持续，维持

参考例句：

• The lasting war debased the value of the dollar.持久的战争使美元贬值。
• We hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。

3 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

4 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

5 frankly   

adv.坦白地，直率地；坦率地说

参考例句：

• To speak frankly, I don't like the idea at all.老实说，我一点也不赞成这个主意。
• Frankly speaking, I'm not opposed to reform.坦率地说，我不反对改革。

6 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。

7 structural   

adj.构造的，组织的，建筑（用）的

参考例句：

• The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
• The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。

8 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

9 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。