The world is facing a silent epidemic, one that’s not caused by pathogens, but rather by memory loss. As the world grows older, Alzheimer’s disease and other dementias (collectively called ADD) are becoming widespread concerns; and nowhere is it as bad as in China.

New research published in PLOS ONE reports that between 1990 and 2021, the number of dementia cases worldwide has doubled. In China, they tripled. This stark contrast isn’t just a demographic accident. It’s a confluence of aging, metabolic diseases, and lifestyle habits that, taken together, form a perfect storm.

What’s happening in China?

To understand why dementia is accelerating so rapidly in China, researchers Siyu Liu and Daoying Geng of Fudan University turned to the Global Burden of Disease database — an enormous trove of health data spanning decades and continents.

Population growth was the biggest factor. China’s population grew dramatically from 1990 to 2021. With more people overall, even if the rate of dementia stayed the same, the number of cases would still rise sharply. But the rate of dementia did increase.

Despite this, however, the number of deaths from dementia dropped. This signifies that people are living longer, healthier lives overall.

So far, nothing surprisng. But the big question is why is the rate of dementia increasing?

The researcher’s analysis showed that the most powerful risk factor for dementia is no longer smoking or genetics. It’s high fasting plasma glucose — chronic, often undiagnosed, high blood sugar. In simpler terms: diabetes and its precursors.

A metabolic epidemic

As economies grow, diets change. Sedentary work replaces physical labor. China rapidly expanded its economy and raised living standards, but it didn’t exactly emphasize individual health. Now, this is showing at the population level.

China’s transformation has been dizzying. And, along the way, metabolic health has suffered. Sugary drinks and processed foods have replaced some traditional staples. By 2021, high blood sugar had become the top preventable risk factor for dementia in China, just as it has globally. Smoking and high body weight also remain major contributors, particularly among men. But much of this is clearly attributable to sugar.

In a way, though, this is good news.

It means that much of the dementia burden isn’t destiny. It’s modifiable. The right interventions — public campaigns to reduce sugar consumption, better diabetes screening, robust tobacco control — could turn the tide.

But time is short.

As China urbanizes and modernizes, the traditional support systems that once supported older adults — like multigenerational households and close-knit family care — are breaking down. At the same time, urban lifestyles are accelerating metabolic risks tied to dementia, including poor diets, physical inactivity, and rising blood sugar levels. This double blow (less social support and more biological risk) means dementia is not only becoming more common but harder to manage.

So how can we manage it?

There is no cure for Alzheimer’s or most dementias. But there are ways to delay them, sometimes for many years. By targeting the metabolic roots of the disease — and by understanding the social dynamics that fuel its spread — countries like China can still change course.

Controlling high blood sugar is the first step. This means identifying and managing type 2 diabetes early, promoting healthy diets low in refined sugar and processed foods, and encouraging regular physical activity. These aren’t just good habits — they’re tools to slow brain decline.

Public health campaigns that reach older adults, especially in rural and underserved areas, can help detect metabolic problems before they become neurological ones. Reducing smoking, especially among men, and addressing obesity are also essential to lowering dementia risk across the population.

But defending against dementia also requires strengthening the social environment. Loneliness and lack of cognitive stimulation are risk factors too. Expanding access to community centers, social programs, and cognitive screening for older adults can help fill the gap left by shrinking family networks. Health systems must prepare for long-term, community-based care — not just medical treatment, but support for daily life and dignity.

If policymakers act on both fronts, biological and social, they can not only reduce future dementia cases but also ease the immense burden already unfolding in households across the country. This holds for both China and the rest of the world.

Journal Reference: Liu S, Geng D (2025) A systematic analysis for disease burden, risk factors, and trend projection of Alzheimer’s disease and other dementias in China and globally. PLoS ONE 20(5): e0322574. https://doi.org/10.1371/journal.pone.0322574