DIRECTIONS: Choose the best answer for each question. Living…
DIRECTIONS: Choose the best answer for each question. Living Longer When it comes to longer lifespans, could genes play a more important role than diet and exercise? Scientists have begun looking at the genes of small, isolated communities to better understand the illnesses of old age and how they might be avoided. In Italy, Ecuador, and the United States, studies are revealing information related to genes that may one day help everyone reach their old age in good health.Taste for Life On a cool January morning in 2013, Giuseppe Passarino drove on a mountain road through orange trees into Calabria, in the far south of Italy. Passarino, a geneticist at the University of Calabria, was headed for the small village of Molochio, a remote town with four centenarians and four 99-year-olds among its 2,000 inhabitants. Soon after, he found 106-year-old Salvatore Caruso in his home. Caruso told the researcher that he was in good health, and his memory seemed excellent. He recalled the death of his father in 1913, when Salvatore was a schoolboy; how his mother and brother had nearly died during the great flu epidemic of 1918-1919; and how he’d been dismissed from the army in 1925 after accidentally falling and breaking his leg in two places. When asked about the reasons for his long life, the centenarian smiled and said in Italian, “No drinking, no smoking, no women.” He added that he’d eaten mostly figs and beans while growing up and hardly ever any red meat. Passarino heard much the same from 103-year-old Domenico Romeo, who described his diet as “a little bit, but of everything.” Passarino is working to understand the reasons that Calabrians live such long lives. In the dim, cool hallway outside his university office stand several freezers full of blood taken from elderly Calabrians. The DNA from this blood has revealed that people who live into their 90s and beyond may have such long lives owing to a gene that affects their sense of taste. This gene gives people a taste for bitter foods like broccoli and field greens – vegetables that promote cellular1 health and aid digestion.Size Matters The quest to understand more about genetic influences on aging has brought scientific attention to people like Nicolas Aazco, known as “Pajarito” – Little Bird in Spanish. Nicolas, 17, said he became aware of the reason for his nickname at age six, when he looked around at his classmates: “I realized that I was going to be smaller than them.” Because of a single gene, Nicolas looks like an eight-year-old and is 115 centimeters tall. That gene causes a condition called Laron syndrome; it is due to this rare condition that he is so small. Nicolas is one of Ecuador’s Laron people, descendants of Europeans who traveled to Ecuador in the 16th century. These travelers carried a gene that sometimes causes short stature; the same genetic mutation has been discovered in other places where these Europeans relocated. In Ecuador, the Laron people settled in small towns and villages scattered across the countryside. Because of a lack of roads, phones, and electricity, the area remained isolated until the 1980s. Over the centuries, the genetic mutation was passed down through the generations. In an interview, Little Bird and some friends – all with Laron syndrome – talked about their lives. Victor Rivera, now 23, was the subject of a famous photograph shown at many scientific meetings, taken when he was four. He was so small that the ear of corn he was holding was slightly larger than his arm. Luis Sanchez, an elder among the group, laughed along with his friends when someone asked if they knew the latest scientific reports about their condition. “We are laughing,” he explained, “because we know we are immune to cancer and diabetes.” Indeed, he is partly right. Researchers have found that people with Laron syndrome have a good chance of living a long life. A 2006 study revealed that no one from a group of people with Laron syndrome developed diabetes, and only one person developed cancer. In a control group of people without Laron syndrome, 5 percent developed diabetes and 20 percent died of cancer. The same gene that causes short stature may also protect people with Laron syndrome from disease.The Gene Hunt Protective genes have also attracted the attention of researchers in the United States. In one study of an isolated, homogeneous population, University of Hawaii researchers have found a gene related to long life in Japanese-American men on the island of Oahu. In yet another study, in La Jolla, California, physician Eric Topol and colleagues are searching through the DNA of about a thousand people they call “the wellderly” – people over the age of 80 who have no chronic diseases such as high blood pressure, heart disease, or diabetes, and have never taken prescription drugs. “There must be modifying genes that explain why these individuals are protected from the deleterious2 genes that affect the aging process,” Topol says. “The hunt is on.” But genes alone are unlikely to explain all the secrets of living to 100. As geneticist Passarino explains, “It’s not that there are good genes and bad genes … It’s certain genes at certain times. And in the end, genes are probably responsible for only 25 percent of living a long and healthy life. It’s the environment, too, but that doesn’t explain all of it either. And don’t forget chance.” This brought to mind Salvatore Caruso, still going strong at 106 years old. Because he broke his leg 88 years ago, it wasn’t mandatory for him to go to Russia with the other soldiers and fight in the war. “Not a single one of them came back,” he said. It’s another reminder that while genes may be an important factor in living longer, a little luck doesn’t hurt.1 Cellular means relating to the cells of animals or plants.2 Something that is deleterious has a harmful effect.What is the main idea of the passage?