Being physically fit at age 18 is linked to a higher IQ, a new study finds. The researchers also show that fitness predicts greater educational and professional achievements later in life. Earlier studies have found links between physical fitness and intelligence(智力)in animals, children and older adults. But the relationship in young adults hasn’t been clear.

In the new study, researchers used data(数据)to examine over 1.2 million young men born in Sweden between 1950 and 1976. All the men had their physical fitness and intelligence assessed(评估) at age 18. The researchers compared this information to details of later achievements in academic(学术), social and economic aspects from other national databases and made some findings.

Fitness in the 18-year-olds was strongly linked to scores on intelligence tests. “Being fit means that you have good heart and lung capacity and that your brain gets plenty of oxygen, ’’ says Dr. Michael Nilsson of the University of Gothenburg. “This may be one of the reasons why we can see a clear link with fitness.” The researchers also found that fit teens were more likely to get a university degree later in life. Fitness at age 18 was also linked to landing better jobs, with Higher pay or management responsibilities.

The findings point to the importance of encouraging physical fitness in teens. “If so, physical education is a subject that has an important place in schools,” says Dr. Maria Aberg of the University of Gothernburg.

It is generally believed that humans can’t live without sleep. As any person suffering from lack of sleep knows, dark circles under the eyes usually stand out after a bad night’s sleep.

But why do people get these dark eye bags? The answer is both genetic (that is, relating to your DNA) and environmental (a result of your everyday living, such as rubbing your eyes or getting too little sleep), said Dr. Carol Clinton, a skin-care researcher in Dublin, Ohio.

But “the biggest reason is genes,” Clinton told Live Science. Eye bags are generally more noticeable in people who, because of genes, have thin or pale skin. When people are tired or very nervous, blood circulation in the eye area becomes slow, allowing blood to pool there, Clinton said. Capillaries（毛细血管）stand out, leading to dark eye circles, she said.

Besides, eye bags result from eyes’ fat moving forward. An age-connected increase in fat beneath the eyeballs leads to eye bags. “Anyway, when your eyes’ fat is moving forward, you may think about having an operation in that area,” Clinton said, “A person can get 9 hours of sleep a night, but still have eye bags because of a genetic development.”

In other cases, environmental problems cause eye bags. For example, allergies（过敏）—especially seasonal allergies—can cause capillaries to stand out. Getting too much sun can also damage and thin the skin, making dark circles under the eyes easy to see. Besides, eating salty foods can cause the body to hold more water, which makes eye bags worse, according to the Mayo Clinic.

The brain, like any other body part, gets old. 【小题1】 For example, women’s brains may age more slowly than men’s. That is the finding of a U.S. study from Washington University School of Medicine.

Researchers there wanted to find out how the brain uses sugar. 【小题2】 They used medical equipment to look at the flow of oxygen and sugar in the brains. The researchers found that the brains of women looked nearly four years younger than those of men. 【小题3】

As our brains age, some mental problems may happen. However, doctors say that about half of the problems can be prevented by simple lifestyle changes.

Whether you are a man or a woman, here are some tips for you to keep your brain young and healthy.

·【小题4】 Experts suggest around seven hours of sleep each night.

·Get aerobic (有氧) exercise for 30~40 minutes three to four times a week. Exercise helps grow brain cells(细胞)and gets better blood flow in the brain.

·Eat a healthy diet. 【小题5】 One example is the diet with lots of vegetables, fruits, grains, and fish.

·Do activities that make you excited and happy.

·Spend time with family and friends.