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

　　We all know that exercise keeps us healthy. But two new studies get more specific. They look at how exercise may lower the risk of two major causes of death – cancer and stroke.

　　One study says exercise may lower the risk for 13 types of cancer. Another says that middle-aged people can reduce their chance of having a stroke by exercising.

　　First let's talk about cancer.

　　Steven Moore of the National Cancer Institute led a team of researchers to study more than 1.4 million people.

　　The study looked at participants in 12 U.S. and European groups. These people reported on their physical activity between 1987 and 2004. The researchers looked at the occurrence of 26 kinds of cancer among the participants during, on average, the next 11 years.

　　Many participants reported walking, running and swimming. The researchers took into account how long they exercised per week, what they ate, if they were obese and if they smoked.

　　In an interview with NBC News, Moore explains that exercise "can help people reduce their risk of heart disease. It can reduce the risk of diabetes." It helps you live longer. And now, he adds, it appears that it may reduce the risks of some cancers."

　　Moore and his team found that exercise lowered the risk of developing:

　　•cancer of the esophagus by 42 percent

　　•liver cancer by 27 percent

　　•lung cancer by 26 percent and

　　•breast cancer by 10 percent.

　　Exercise also lowered the risk of a specific type of leukemia by 20 percent.

　　Moore told NBC that there are some possible explanations for the findings. First, exercise can lower hormone levels like estrogen. Lower levels of estrogen would lower the risk of breast and endometrial cancers. He adds that exercise helps maintain insulin and that may lower overall inflammation in the body.

　　However, one type of cancer puzzled the researchers.

　　They found that exercise increased the chance of developing prostate cancer by five percent. But they wrote that they could not explain the connection.

　　The researchers also found that people who did heavier exercises had a slightly higher rate of skin cancer. This, they say, could be from more sun exposure.

　　Now, how exercise affects strokes.

　　The more fit a person is in middle age, the less likely he or she will have a crippling stroke after age 65.

　　This is the result of a new study by the University of Texas Southwestern Medical Center.

　　Doctors studied 20,000 men and women between the ages of 45 and 50. They found that those who were most fit from moderate to vigorous exercise had a 37 percent lower risk of a stroke than those who were least fit.

　　They say the lowered risk of a future stroke was present even when the subjects had other risk factors. These factors include high blood pressure and type-2 diabetes.

　　The researchers of this study say they want doctors to not ignore low levels of exercise and fitness as risk factors for a stroke.

　　This study was published in the latest issue of the medical journal called Stroke.

　　I'm Anna Matteo.

　　VOA News reported this story. Anna Matteo adapted it for Learning English. Hai Do was the editor.