Health & Science

New hope for Alzheimer’s

Alzheimer’s disease strikes one in eight Americans over age 65, but scientists still know little about its causes and have yet to develop an effective treatment. Now two studies, the largest ever to examine the complex disease, have identified five genes linked to Alzheimer’s onset—providing new insight into why the disease develops and clues on how to slow or block its progress. “I’ve been in Alzheimer’s genetics since 1985, and I would have to say this is the most exciting event that’s happened,” lead author Gerard D. Schellenberg of the University of Pennsylvania tells USA Today. More than 100 scientists from the United States and Europe pooled data to analyze the genes of 11,000 dementia sufferers and 43,000 healthy individuals—an unprecedented sample size. They found that dementia was related to the presence of five newly discovered genes, which affect cholesterol levels, the movement of fat inside cells, and inflammation. The presence of any one of the genes increases a person’s risk of developing Alzheimer’s by 10 to 15 percent. Figuring out how the 10 genes linked to the disease thus far affect the brain, researchers say, could lead to new drug treatments within the next decade. “We still have a long way to go,” said Cardiff University researcher Julie Williams, “but the jigsaw is beginning to come together.”

The Arctic’s ozone hole

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The ozone layer over the Arctic Circle developed a giant hole this winter, scientists say. Over the North Pole, 40 percent of the ozone layer has disappeared—a record seasonal loss. Ozone high in the atmosphere shields the Earth from harmful UV rays, and it fluctuates seasonally; usually about 25 percent of the Arctic’s ozone layer fades every winter. In the 1970s, scientists discovered that chlorofluorocarbons (CFCs) used in air conditioners, refrigerators, and aerosols were drifting high into the atmosphere and combining with ozone, stripping the planet of its natural UV protection. UV rays can cause cancer, and damage plants and marine life. As a result, most nations are phasing out CFCs. But the CFCs already released will linger for decades. As weather moves the ozone hole farther south this spring, researcher Markus Rex tells Discovery News, people in the northern part of the U.S. and Canada may get increased UV exposure. “Sunburn times could drop to 20 minutes,’’ he said.

Why the obese keep eating

Could obesity be treated as a form of drug addiction? A new study suggests that some overweight people may be addicted to eating in the same way that, say, a cocaine addict craves another hit of his favorite drug. Researchers at Yale University gave a small group of young women questionnaires to determine their levels of food addiction. Then they scanned the volunteers’ brains while the women looked at a picture of a milk shake covered with chocolate syrup. In women with eating problems, brain areas related to pleasure and craving lit up—much as they do in drug addicts anticipating a fix. And when the women were allowed to sample the shake, the food addicts showed less-than-normal activity in the reward centers of their brains, meaning they felt less satisfied. In effect, they’d developed both a need and a tolerance for sugar and fat; like drug addicts, they require more and more to satisfy their cravings. “It’s a one-two punch,” study author Ashley Gearhardt tells Health.com. “When you get what you are after, there’s less of an oomph than you expected, so you consume more.”

Drinking their way to an F

It’s no secret that drinking alcohol is a big activity on college campuses. Now a new study finds that how much and how frequently students drink is one of the best predictors of the grades they get. “The more time spent partying with alcohol, there’s a significant decrease in GPA,” study author and George Mason University researcher Todd Wyatt tells TheDailyBeast​.com. He and a colleague surveyed 13,900 incoming freshmen at 167 schools, and were surprised to find that time spent on the modern distractions—including Facebook and TV—had no measurable impact on grades. Spotty attendance in class also had little effect. Two factors did play a big role in grades: the amount of time spent studying every week, and how much and how often students drank. Why? Being drunk or hungover may simply discourage students from studying. It might also be that students who see college primarily as a place to “party” don’t take academics very seriously. Academic excellence, Wyatt says, requires “studying hard and staying off the bottle. That’s it.”