The Alzheimer’s Curve: Rising Numbers, Shifting Risks
When people hear that Alzheimer’s is “on the rise,” they often imagine a mysterious epidemic sweeping through aging populations. The truth is subtler—and more human. Alzheimer’s isn’t spreading like a virus; it’s accumulating as we live longer. Across the world, the number of people with Alzheimer’s has climbed steadily for decades. In the early 1990s, there were roughly four million cases. Today, there are close to ten million, and projections suggest nearly twenty million by the mid‑2030s. Yet the rate —how often new cases appear per 100,000 people—hasn’t changed much. In some countries, it’s even declined slightly. So what’s happening? We’re not getting sicker; we’re getting older. And we’re getting better at recognizing what’s wrong. The arithmetic of aging Every decade adds millions of people to the age bracket where Alzheimer’s risk peaks—our eighties and nineties. Longer life expectancy means more people reach those years, and better medical care means they survive long e...