Cases of dementia expected to double by 2060; what can be done to

The risk of developing dementia is higher than previously thought, and the number of cases is expected to double in the coming decades, according to a new study. Data indicates that more than two in five Americans over the age of 55 may develop dementia in their lifetime.

A recent study, published Jan. 13 in the medical journal Nature Medicine, estimates that about 42 percent of Americans ages 55 and older will suffer from dementia at some point in their lives, provided they live long enough. In 2020, there were approximately 514,000 new cases of dementia in the United States, but this number is expected to increase to nearly 1 million new cases per year by 2060.

This sharp increase is largely attributed to the aging of the “baby boomer” generation, the youngest of which are now over 60 years old. By 2040, everyone in this generation will be at least 75 years old, an age at which the risk of dementia increases significantly.

Professor David Tanne, director of the Institute of Cognitive Neurology and Stroke at the Rambam Healthcare Campus and president of the Israeli Society for Cognitive Neurology, emphasizes the importance of these findings: “This trend is not not unique to the United States; it is also very relevant. to the Israeli population. In Israel, we rely on surveys based on dementia diagnoses documented in electronic health records of health maintenance organizations (HMOs).

“However, these data represent only the tip of the iceberg. The new findings suggest that the lifetime risk of developing dementia in Israel is much higher than previously estimated, and that the number of cases is also expected to double These findings highlight the urgent need.

The study assessed cumulative lifetime risk of dementia using data from the Atherosclerosis Risk in Communities (ARIC) study, a long-term community cohort study in the United States. The research included 15,043 participants aged 55 and over who did not have dementia at the start of the follow-up period. The study population consisted of 26.9% black participants, 55.1% women, and 30.8% individuals carrying at least one copy of the APOE ε4 allele, a well-established genetic risk factor for dementia.

The research methodology involved a median follow-up period of 23 years (ranging from 16 to 27 years) during which participants were tracked through cognitive assessments, telephone interviews, medical records, and death certificates. Results revealed that 42% of participants aged 55 and older developed dementia during their lifetime, with higher risks observed among women (48% versus 35% among men), African Americans ( 44% versus 41% among Whites) and APOE ε4 carriers. (59% for those with two copies of the allele versus 39% for non-carriers).

“Dementia does not happen overnight: it is a gradual process that extends over many years,” explains Professor Tanne. “It is also important to clarify that dementia is not a single disease, but rather an umbrella term encompassing a set of conditions that impair memory, cognitive abilities and behavior. When the impairment becomes severe enough to interfere with daily functioning, it is classified On the other hand, when there is a decline in memory and cognitive abilities which is milder and does not disrupt daily life, we speak of “mild cognitive impairment”.

The study also found that the risk of dementia varies with age: only 17% of cases are diagnosed before the age of 75, with the average age of diagnosis being 81. In women, the lifetime risk of developing dementia is 48% (approximately one in two women), compared to 35% in men (approximately one in three men), mainly due to life expectancy longest in women.

Neurodegenerative diseases, particularly Alzheimer’s disease, are the most common cause of dementia, followed by cerebrovascular disease and stroke. Major risk factors for dementia include older age, genetic predisposition (e.g., APOE ε4), cardiovascular disease, hypertension, diabetes, and obesity. Additionally, conditions such as untreated hearing loss and head injuries increase the risk.

“In old age, most cases of dementia result from a combination of factors, such as concomitant cerebrovascular disease with neurodegenerative processes that damage brain tissue,” explains Professor Tanne. “Since cerebrovascular disease contributes significantly to accelerated cognitive decline, it is crucial to maintain the health of cerebral blood vessels and prevent cardiovascular disease.”

Maintaining brain health can be achieved through management of modifiable risk factors, such as cardiovascular disease, high cholesterol, and hypertension. Lifestyle interventions, such as avoiding smoking, reducing sedentary behaviors, maintaining a healthy weight, engaging in regular physical activity, participating in mentally stimulating activities, and fostering supportive social connections, can significantly improve cognitive health over time. time.

Professor Tanne emphasizes that although age and genetic predisposition are uncontrollable factors, there are many concrete measures to reduce the risk of dementia:

According to researchers, only about 20 percent of adults in the United States meet healthy lifestyle goals, and only 30 percent of older adults with hearing loss use hearing aids. The study also highlights significant racial disparities, with dementia diagnosis rates higher and onset earlier among black adults than white adults. These disparities are attributed to structural racism, unequal access to education and nutrition, and inequities in health care.

Professor Tanne also points to higher rates of dementia among the Arab population in northern Israel, emphasizing the need for culturally tailored interventions: “We provide early dementia diagnosis services in northern Israel and We found that dementia rates among the Arab population are higher than among the Jewish population. Dementia tends to appear at a younger age, and patients often seek medical attention in later stages of the disease. Our goal is to understand contributing factors and provide culturally competent care.

He adds: “High rates of dementia in the Arab population may arise from a combination of factors, including a higher prevalence of untreated cardiovascular disease, potential genetic factors and lifestyle factors. In this population, there is a need for Arabic-speaking neurologists. and culturally appropriate services.

Professor Tanne highlights the growing burden of dementia as life expectancy increases: “The current burden of dementia is significant and, as in the United States, it is expected to increase sharply in Israel. As we improve our management of chronic diseases and cancer, and life expectancy continues to increase, tackling dementia and its consequences will become a central challenge in the years to come. »

However, Professor Tanne notes that recent research suggests that around 50% of dementia cases are preventable or at least delayable. He adds that delaying the onset of dementia by just five years could reduce the prevalence of dementia in Israel by almost half, a result with profound implications for health systems, the economy and society.

“When half of cases are preventable or delayable, effective prevention planning becomes essential,” he says. “We can achieve this through primary prevention – promoting brain-healthy lifestyles and managing cardiovascular risk factors – as well as early and accurate diagnosis of cognitive decline before dementia develops .”

Recent diagnostic criteria published by the American Alzheimer’s Association advocate the use of biological markers rather than relying solely on cognitive tests. Additionally, new biologic therapies designed to slow disease progression have become available, along with additional drugs in late stages of development. Researchers emphasize that public policies must prioritize prevention and healthy aging, because dementia is not inevitable. Through daily preventive measures, it is possible to significantly improve the quality of life and cognitive health of older people.

Professor Tanne concludes: “We have the opportunity to act strategically at a national level, implementing measures such as promoting primary prevention to maintain brain health, early and accurate diagnosis of cognitive decline and providing treatment adapted to high-risk populations. When these cases occur at older ages, the actions required for national planning must begin decades earlier, requiring a fundamental change in mindset. »