Fasting May Help Your Brain

 

From VOA Learning English, this is the Health & Lifestyle report.

More than one billion Muslims around the world observe Ramadan, Islam’s holy month. Fasting during Ramadan is a requirement for believers. This means they are barred from having sex, smoking, drinking and eating from sunrise to sunset.

Today, we talk about fasting involving only food. Apart from spiritual or religious reasons, what effects does not eating have on human health?

A team of researchers in the United States says fasting is good for our brain.

Mark Mattson is a neuroscientist at Johns Hopkins University in Baltimore, Maryland. He and others have studied how dietary restrictions² might protect your brain from neurological diseases that get worse over time. Two examples of these diseases are Alzheimer’s and Parkinson’s.

His team found that controlling and restricting calories may improve a person’s memory, emotions and state of mind.

Mattson says his studies are built upon years of research that have confirmed links between how many calories a person eats and mental ability. Calories are a measure of energy in food.

A report in the Johns Hopkins Health Review describes the links. It said that every time we eat, a sugar called glucose³ is stored in the liver as glycogen. It takes your body about 10 to 12 hours to use up all of the glycogen.

The report said, “After the glycogen is used up, your body starts burning fats, which are converted⁵ into chemicals used by neurons as energy. These chemicals are important to learning, memory and overall brain health.”

However, if you eat three meals a day, with snacks in between, your body does not have time to use up all of the glycogen in the liver. So, the learning and memory chemicals are not produced.

Mattson said that physical exercise can also use up the glycogens. He added that it was not surprising that “exercise has been shown to have the same positive effect on the brain as fasting.”

The researchers found that cutting down on food at least two days a week can improve neural⁶ connections in the hippocampus. This part of the brain controls emotions and plays a part in long-term memory.

A calorie-controlled diet also protected neurons against the build-up of amyloid plaques⁸. Amyloid plaque⁷ is a protein commonly found in the brains of people with Alzheimer’s.

Ways to fast safely

If you want to try fasting, Mattson has two suggestions.

The first is a diet called 5:2. On this diet, you eat only 500 calories for two nonconsecutive days each week. Then the rest of the week, you eat a healthy diet with a normal amount of calories. A normal amount for women is about 2,000. For men, it is 2,500.

The other suggestion is time restriction¹. In one day, you eat all of your meals in one eight-hour period. This should give your body the time it needs to use up all the glycogen in the liver, start burning fat and produce those chemicals we talked about earlier.

However, Mattson warned that if you have never fasted before, do not begin fasting immediately.

The researchers say our bodies need to get used to calorie restrictions. They compare it to a person who is not physically¹⁰ active and then decides to run a long distance race without any training. They may not like fasting and give up easily.

Mattson said, “It’s the same thing as if you’ve been eating three meals a day plus snacks, and then you’re not eating anything at all for two days. You’re not going to like it.”

He suggested starting with one day of limited food intake¹¹ every week. Then build up to two days. Mattson warned that a person new to fasting might experience headaches, lightheadedness and moodiness¹². But his experiments show that these problems should pass quickly and a person’s mood will improve.

If you have any questions or health concerns, talk with your doctor before taking any action.

And that’s the Health & Lifestyle report. I’m Anna Matteo.

Words in This Story

fast – v. to eat no food for a period of time

convert⁴ – v. to change (something) into a different form or so that it can be used in a different way — usually + to or into : The cells absorb light and convert it to energy.

neurons – n. a cell that carries messages between the brain and other parts of the body and that is the basic unit of the nervous system

snack – n. a small amount of food eaten between meals

positive – adj. good or useful

nonconsecutive – adj. not being in a sequence : not consecutive⁹ : Exercise three times a week on nonconsecutive days.

mood – n. the way someone feels : a person's emotional state : moody¹³ – adj. having moods that change often moodiness – n.

1 restriction   

n.限制，约束

参考例句：

• The park is open to the public without restriction.这个公园对公众开放，没有任何限制。
• The 30 mph speed restriction applies in all built-up areas.每小时限速30英里适用于所有建筑物聚集区。

2 restrictions   

约束( restriction的名词复数 )； 管制； 制约因素； 带限制性的条件（或规则）

参考例句：

• I found the restrictions irksome. 我对那些限制感到很烦。
• a snaggle of restrictions 杂乱无章的种种限制

3 glucose   

n.葡萄糖

参考例句：

• I gave him an extra dose of glucose to pep him up.我给他多注射了一剂葡萄糖以增强他的活力。
• The doctor injected glucose into his patient's veins.医生将葡萄糖注入病人的静脉。

4 convert   

v.（在形式、状态、用途等方面）（使）改变

参考例句：

• I must convert sorrow into strength.我要化悲痛为力量。
• At what rate does the dollar convert into pounds?美元以什么汇率兑换成英镑？

5 converted   

adj.更换信仰的，修改的v.（使）转变( convert的过去式和过去分词 )；（使）转化；皈依；改变（信仰）

参考例句：

• The hotel is going to be converted into a nursing home. 那家旅馆将被改建成私人疗养院。
• He's living in a converted loft in lower Manhattan. 他住在下曼哈顿的一间改建的阁楼里。 来自《简明英汉词典》

6 neural   

adj.神经的，神经系统的

参考例句：

• The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
• The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。

7 plaque   

n.饰板，匾，(医)血小板

参考例句：

• There is a commemorative plaque to the artist in the village hall.村公所里有一块纪念该艺术家的牌匾。
• Some Latin words were engraved on the plaque. 牌匾上刻着些拉丁文。

8 plaques   

（纪念性的）匾牌( plaque的名词复数 )； 纪念匾； 牙斑； 空斑

参考例句：

• Primary plaques were detectable in 16 to 20 hours. 在16到20小时内可查出原发溶斑。
• The gondoliers wore green and white livery and silver plaques on their chests. 船夫们穿着白绿两色的制服，胸前别着银质徽章。

9 consecutive   

adj.连续的，联贯的，始终一贯的

参考例句：

• It has rained for four consecutive days.已连续下了四天雨。
• The policy of our Party is consecutive.我党的政策始终如一。

10 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

11 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。

12 moodiness   

n.喜怒无常；喜怒无常，闷闷不乐；情绪

参考例句：

• Common symptoms can include anxiety, moodiness and problems with sleep. 常见的症状包括焦虑、闷闷不乐和睡眠问题。 来自互联网

13 moody   

adj.心情不稳的，易怒的，喜怒无常的

参考例句：

• He relapsed into a moody silence.他又重新陷于忧郁的沉默中。
• I'd never marry that girl.She's so moody.我决不会和那女孩结婚的。她太易怒了。