What about prevention? There is accumulating evidence that exercise, eating fish or other sources of omega-3 fatty acids, and remaining intellectually and socially engaged throughout life reduce the risk of Alzheimer's. But last year a panel assembled by the National Institutes of Health concluded that the evidence on lifestyle interventions is inconsistent and inconclusive, pretty much across the board. "There are suggestions that some things might be effective, but there isn't strong, high-grade evidence for any of them," says Neil Buckholtz, chief of the dementias of aging branch of the National Institute on Aging. The NIA is now running several large studies to see if exercise, diet, or social or intellectual engagement will reduce risk.
Having had a stroke substantially raises the odds of Alzheimer's, as does having diabetes. But the biggest known risk factor is one people can do nothing about: a family history of the disease. People carrying one copy of variations in a gene called APOE are at about a threefold risk, while those carrying two copies have a whopping 12-fold risk. But it appears possible now that many genes, perhaps even a hundred, may each confer a tiny increased risk of developing Alzheimer's. Still, Rudy Tanzi, an Alzheimer's geneticist at Harvard Medical School, is hopeful that by 2020, a screen of a person's genome will reliably estimate his or her risk of developing the disease. Ideally, the people at highest risk will then have scans or spinal fluid or blood tests regularly to detect accumulating beta amyloid. Once it is seen, they'll begin taking the equivalent of a "statin for the brain" to reduce the load. And Alzheimer's will become as preventable as heart disease is today.
AUTISM: Fighting it in toddlerhood, with play
It was a breakthrough that Lynn Locke of Lodi, Calif., calls "the greatest joy in our lives." After her son Colson, then 3 years old, participated in a year of novel therapy for autism, the brain disorder that inhibits children's ability to communicate and develop relationships, he finally spoke his first word: "Up." A year later, Colson "talks a mile a minute" and is enrolled in a regular preschool class. Scientists are racing to find autism's causes and the drugs that may help treat the disorder, which now afflicts 1 in every 110 children and 1 in 70 boys, according to the Centers for Disease Control and Prevention. But it's behavior therapies like the one that helped Colson that are giving families immediate hope. His success came as part of research at the University of California, Davis Medical Center testing the Early Start Denver Model. The model holds that children as young as 12 or 18 months can improve significantly with more than two dozen hours a week of intensive therapy emphasizing interactive play; often, interventions don't begin until preschool or kindergarten and are more focused on practicing speech and modifying behavior. The goal is to "reduce autism symptoms or prevent them from ever developing," says Geraldine Dawson, a professor of psychiatry at the University of North Carolina-Chapel Hill School of Medicine who helped develop the model, and lead author of a 2009 study of it. Dawson is also chief science officer for Autism Speaks, a nonprofit that funds research. Her report noted that the IQs of children who received Early Start therapy rose on average by close to 18 points, compared to 7 points in the group receiving traditional autism therapies. The Early Start group's listening and understanding skills rose by about 19 points, almost twice the level of improvement in the control group.
The Early Start therapy is built around activities that require the autistic child to make eye contact, take turns, and communicate. Colson and his therapists, parents, and siblings played board games, sang and danced, and marched around the house. When Colson wanted something, he learned to ask for it by pointing and making the sound of a T (his therapist's first initial). He made an M sound to get his mom's attention. Within a few months, he was addressing people by name. Sally Rogers, the UC-Davis psychologist behind the model, is now launching a study of play therapies aimed at infants.