It's the day after Easter, and the first crocus shoots have ventured tentatively above the ground at the convent on Good Counsel Hill. This is Minnesota, however; the temperature is 23[degrees]F and the wind chill makes it feel far colder. Yet even though she's wearing only a skirt and sweater, Sister Ada, 91, wants to go outside. She wants to feed the pigs.
But the pigs she and the other nuns once cared for have been gone for 30 years. Sister Ada simply can't keep that straight. In recent years, her brain, like a time machine gone awry, has been wrenching her back and forth between the present and the past, depositing her without warning into the days when she taught primary schoolchildren in Minnesota or to the years when she was a college student in St. Paul. Or to the times when she and the sisters had to feed the pigs several times a day.
Like some 4 million Americans, Sister Ada (not her real name) is suffering from Alzheimer's disease; as the years go by, she'll gradually lose her memory, her personality and finally all cognitive function. But advanced age does not automatically lead to senility. Ada's fellow nun, Sister Rosella, 89, continues to be mentally sharp and totally alert, eagerly anticipating the celebration of her 70th anniversary as a sister without the slightest sign of dementia. In a very real sense, this pair of retired schoolteachers haven't finished their teaching careers. Along with hundreds of other nuns in their order, the School Sisters of Notre Dame, they have joined a long-term study of Alzheimer's disease that could teach the rest of us how to escape the worst ravages of this heartbreaking illness.
The groundbreaking research they are helping conduct probably won't lead directly to any new drugs, and it's unlikely to uncover a genetic or biochemical cause of Alzheimer's. Doctors know, however, that preventing disease can be a lot easier and cheaper than trying to cure it. It was by studying the differences between people who get sick and people who don't--the branch of medical science known as epidemiology--that doctors discovered the link between smoking and lung cancer, between cholesterol and heart disease, between salt and high blood pressure. Epidemiology also led to the understanding that cooked tomatoes may help protect against prostate cancer, and that fruits and vegetables tend to stave off cancers of all sorts.
Now it's Alzheimer's turn. Precious little is known about this terrible illness, which threatens to strike some 14 million Americans by 2050. Its precise cause is still largely mysterious, and effective treatments are still years away. But epidemiologists are beginning to get a handle on what kinds of people are most seriously ravaged by Alzheimer's--and, conversely, which people tend to escape relatively unscathed.