Study Finds 14 Modifiable Risk Factors Could Prevent Nearly Half of Dementia Cases

A 2026 study published in The Lancet Healthy Longevity identified 14 modifiable risk factors that could prevent or delay nearly 45 percent of dementia cases globally.

The factors span three life stages. Early-life risks include low education. Midlife risks include hearing loss, hypertension, obesity, high LDL cholesterol, and traumatic brain injury. Lifestyle and environmental risks include physical inactivity, smoking, diabetes, excessive alcohol consumption, social isolation, untreated vision loss, depression, and exposure to air pollution.

A separate study led by the University of Southern California analyzed data from 214,251 adults across 14 countries and regions. It found that while the biological impact of these risk factors is consistent, their prevalence depends heavily on the country.

Low education was the leading risk factor in many low- and middle-income countries, affecting 85.6 percent of older adults in China compared to 12 percent in the United States. Obesity was significantly more prevalent in high-income countries, affecting 44.9 percent of participants in the United States versus 13.3 percent in India.

Researchers say effective dementia prevention must be tailored to the specific risk profile of a population. A country with high rates of low educational attainment should prioritize investments in schooling, while a country struggling with obesity should focus on metabolic health programs.

Hearing loss stands out as a high-yield target for intervention globally. Experts recommend routine audiological screening and access to hearing aids as a foundational component of dementia prevention strategies.