June 11, 2025
People born more recently are at lower risk of developing dementia at any given age than those born in earlier generations, a new analysis suggests. The trend was particularly pronounced for women.
But while younger generations may be less likely to develop dementia at the same age as their parents or grandparents, the authors note, the burden of Alzheimer’s disease in coming decades will continue to grow as the population ages. More than 7 million Americans are living with Alzheimer’s disease, the highest number ever recorded, according to a recent report from the Alzheimer’s Association. That number is expected to double in coming decades.
For the study, published in JAMA Network Open, researchers in Australia analyzed health data spanning multiple decades from three long-running studies on aging and brain health. The studies included health information on 99,420 American adults, 21,069 Europeans, and 32,490 people living in England.
The researchers looked at a subset of these patients, analyzing scores on cognitive tests and other health information to determine whether someone had dementia or was likely to develop it. They also sifted the study population by age, representing different generations.
Not surprisingly, the older someone was, the more likely they were to develop Alzheimer’s or another form of dementia. However, at a given age, people from more recent generations were less likely to develop dementia than those from earlier generations. For example, 25.1 percent of those born between 1890 and 1913 developed dementia by their early to mid 80s, compared with 15.5 percent of those born between 1939 and 1943.
The study did not look at why earlier generations may have been more likely to develop dementia at younger ages than later generations, but the researchers discussed several theories.
One theory was increased access to education. In recent decades, men and particularly women have greater opportunities overall to continue their schooling. The more years spent in formal education, the lower the likelihood of developing Alzheimer’s disease, studies suggest. Education is thought to build brain connections and help gird the brain against the onslaught of a disease like Alzheimer’s. That may be one reason why in recent generations, women in particular were less likely to develop dementia at any given age than their parents or grandparents.
Lifestyle factors and medical advances may also play a role. Fewer people in recent years are smokers, for example, and smoking is a well-recognized risk factor for dementia. (Smoking is also banned now in many public places, so smokers in general are smoking less.) Preventive and medical treatments for heart disease, stroke, high blood pressure and diabetes — all risk factors for Alzheimer’s and other forms of dementia — have also improved and become more widely accessible in recent decades. Good hearing is tied to a lower risk of Alzheimer’s disease, and access and improvements in hearing aids have improved in recent decades.
Regardless of your Alzheimer’s risk or when you were born, research shows that some 40 percent of the cases of Alzheimer’s disease and other forms of dementia could be prevented or delayed by targeting modifiable risk factors throughout your life. In addition to the steps noted above, other modifications include: stay socially connected, remain physically active, try to maintain a healthy weight, get treated for depression if you have it, avoid head injuries, don’t drink alcohol to access, and minimize exposure to air pollution.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Sources: Xiaoxue Dou, MSc; Sabrain Lenzen, PhD; Luke B. Connelly, PhD; et al: “Generational Differences in Age-Specific Dementia Prevalence Rates.” JAMA Network Open, June 2, 2025.
Alzheimer’s Disease Facts and Figures, annual report, May 2025, Alzheimer’s Association.
