Green tea is a type of tea which is made from the     1     (process) leaves of tea trees. It originates from China. Green tea has been subjected to many scientific studies to determine the extent of its health benefits. But it is only during the last two decades     2     research regarding the health benefits of drinking green tea has been established.

Results of a study in 1994 published by the Journal of the National Cancer Institute stated that Chinese men and women who drank green tea     3     (regular) reduced the risk of     4     (get) cancer by almost 60 percent. Another study conducted by the University of Purdue also claimed that green tea     5     (contain) a compound which prevents the growth of cancer cells.

Green tea has many health benefits. More studies suggest that aside from its ability to prevent cancer, it is also believed     6     (prevent) certain medical conditions such as heart diseases and     7     (infection). Green tea is also reported to strengthen the immune system.

Green tea is rich     8     a substance called EGCG. This substance has the ability to depress the growth of cancer cells     9     actually kill existing cancer cells without destroying healthy tissues.

According to     10     (tradition) Chinese medicine, green tea has the ability to kill bacteria that causes food poisoning.

3 . Is It Worth Buying Organic Food?

Organic food, grown without artificial chemicals, is increasingly popular nowadays. Consumers have been willing to pay up to twice as much for goods with organic labels (标签). However, if you think paying a little more for organic food gets you a more nutritious (有营养的) and safer product, you might want to save your money. A study led by researchers at Stanford University says that organic products aren’t necessarily more nutritious, and they’re no less likely to suffer from disease-causing bacteria, either.

The latest results, published in the Annuals of Internal Medicine, suggest that buyers may be wasting their money. “We did not find strong evidence that organic food is more nutritious or healthier,” says Dr. Crystal Smith-Spangler from Stanford. “So consumers shouldn’t assume that one type of food has a lower risk or is safer.”

For their new study, Smith-Spangler and her colleagues conducted a review of two categories of research, including 17 studies that compared health outcomes between consumers of organic against traditional food products, and 223 studies that analyzed the nutritional content of the foods, including key vitamins, minerals and fats.

While the researchers found little difference in nutritional content, they did find that organic fruit and vegetables were 20% less likely to have chemicals remaining on the surfaces. Neither organic nor traditional foods showed levels of chemicals high enough to go beyond food safety standards. And both organic and traditional meats, such as chicken and pork, were equally likely to be harmed by bacteria at very low rates. The researchers did find that organic milk and chicken contained higher levels of omega-3 fatty acids, a healthy fat also found in fish that can reduce the risk of heart disease. However, these nutritional differences were too small, and the researchers were unwilling to make much of them until further studies confirm the trends.

Organic food is produced with fewer chemicals and more natural-growing practices, but that doesn’t always translate into a more nutritious or healthier product. The U.S. Department of Agriculture (USDA) states that “Whether you buy organic or not, finding the freshest foods available may have the biggest effect on taste.” Fresh food is at least as good as anything marketed as organic.

4 . Astronauts get to experience many interesting attractions. When astronauts go to space, they can become weightless. They get to see Earth as a little blue dot. Astronauts get to experience shooting up into space at 20,000 miles per hour. That is more than three times faster than an airplane. Sill, food is not one of the interesting parts of being an astronaut. Space travelers have had to eat strange foods. One example is liquid salt and pepper.

However, the menu for astronauts is going to grow. Scientists have been growing lettuce in outer space. The lettuce is just as safe, nutritious(有营养的) and tasty as lettuce grown on Earth Gioia Mass works at the NASA Kennedy Space Center in Florida. She is the lead scientist on the lettuce growing project. She said that growing food in space could be pivotal for astronauts on long missions(任务). Massa says that today’s space food may not work for these longer missions. This packaged food is stored for a long time. The quality and taste of the food goes down. In addition, the vitamins in the food start to breakdown. Massa says the astronauts may not get enough nutrition from these foods during long missions.

She also added that there could be another benefit to growing food in space. Looking after plants could help astronauts emotionally. Space food has improved in recent years. Many astronauts visit the International Space Station (ISS). It is a research station in outer space. Anything sent to ISS has to be perfect on a taste test. Even so, astronauts can grow tired of eating the same old meals. Massa says many of the astronauts end up losing weight.

The space-grown lettuce was similar to Earth-grown lettuce. In fact, some of the space-grown plants had more nutrients than Earth-grown lettuce. The space lettuce also had higher levels of bacteria(细菌). This was possibly because the lettuce grew in a warmer, more humid system. However, none of this bacteria was dangerous.

5 . Salt was so valuable in ancient Rome that soldiers were sometimes paid with it. In fact, the word salary comes from the Latin word sal, for salt. When a soldier was doing an awful job, his paycheck might be cut, which is how we got the expression “not worth his salt.” Salt can still he valuable today. Amethyst Bamboo 9x salt, which rings up at &398 a pound, may be the most expensive in the world. This pricey stuff takes a lot of time to produce — it’s roasted nine times inside a bamboo pole at temperatures over 1,400 degrees F.

Historically, salt’s value came from its ability to preserve food. Venice, Italy, may be famous for its canals now, but salt imports helped its rise as an important trade power by the end of the 13th century. Salt also took on a great deal of symbolic value, like “old salt” referring to an experienced sailor. Salt is mentioned so many times in the Bible. For instance, “the salt of the earth” is used to describe a person who is dependable; “a covenant of salt” means a firm promise.

Most people know about the health risks associated with sodium (钠), but reducing your intake isn’t always easy. Even foods that don’t taste salty may contain it. If you are looking for sodium-free flavoring, try garlic, pepper, rosemary and other spices or herbs.

Still, we all need at least some salt. It promotes the transport of nutrients and oxygen, allows nerves to send messages, and helps our muscle work. The average adult’s body contains about 250 grams of sodium.

Consumption of too much salt can be deadly. For older folks especially, a heavy hand with the saltshaker may raise blood pressure, causing hypertension and hurt the head. A study of 975 people between the ages of 60 to 80 and with high blood pressure found that reducing sodium in their diets was associated with lower risk of headache.

6 . Organic food (有机食品) is very popular. It is also expensive. Some organic food costs twice as much as non-organic food. Some parents and pet owners pay up to 200 percent more for organic food while some people think organic food is a waste of money.

There is one main difference between organic and non-organic food. Organic farms do not use agricultural chemicals, such as pesticides (杀虫剂). This makes sure that the products are natural.

Some people think “organic” means “locally grown”. In the beginning, this was true. Over time organic farming became more difficult. The demand for organic food grew larger than the supply. Small companies had to sell out to large companies. There weren’t enough organic materials. This made it difficult for many organic companies to stay in business. Today, many large companies have an organic line of products.

Is organic food more nutritious ( 有 营 养 的 )? This is part of the debate. Many farmers and consumers (消费者) believe it is. They think agricultural chemicals cause health problems, such as cancer. Many health experts disagree. Few studies prove that organic food prevents health problems. Health experts worry more about bacteria (细 菌 ). These can come into contact with organic and non-organic food. Doctors recommend washing produce very carefully.

Most people agree that naturally grown food tastes better. Is tastier food worth the extra money? This is a matter of opinion. Whether it is healthier or not may require more research. However, organic consumers argue it is better to be safe than sorry.