The number of people who develop dementia each year in the U.S. will double over the next 35 years, to about 1 million people a year by 2060, and the number of new cases among Black Americans per year will be 3.5 million, according to a new study. It is said that it will double.
This increase is primarily due to an aging population, as many Americans are living longer than previous generations. By 2060, some of the youngest baby boomers will be in their 90s and many millennials will be in their 70s. Older age is the biggest risk factor for dementia. The study found that most of the risk of dementia occurs after the age of 75, and increases even more once a person reaches the age of 95.
The study, published Monday in Nature Medicine, found that adults over 55 have a 42 percent risk of developing dementia during their lifetime. This is significantly higher than previous lifetime risk estimates, and the results were more diverse than previous studies, where the study population was primarily white participants and the most up-to-date information on the health and longevity of Americans. The authors believe that this is due to the fact that
Some experts said the new lifetime risk estimates and projected annual increase in cases may be too high, but agreed that dementia cases will rise rapidly in the coming decades.
“Even if the rate were significantly lower, the number of people with dementia, their families, and the burden on society would still increase significantly, just because the number of older adults in the United States is increasing.” Dr. Kenneth Langa, a professor at the University of Michigan School of Medicine, said he has studied dementia risk but was not involved in the new study.
Dementia is already taking a huge toll on American families and the country's health care system. Studies have found that more than 6 million Americans currently have dementia, and nearly 10 percent of people over the age of 65 have the disease. Dementia kills more than 100,000 people and costs more than $600 billion in long-term care and other costs in the United States each year, experts say.
Dr. Joseph Koresh, director of the New York University Grossman School of Medicine's Institute for Optimal Aging and leader of the study, says that if the new predictions hold true, about 12 million Americans will become unidentified by 2060. He said he would become ill. 100 researchers from 10 universities.
The authors and other experts said the study supports the urgency of trying to prevent or delay the onset of dementia. Their main recommendation is to improve people's cardiovascular health through medication and lifestyle changes. Strengthen efforts to prevent and treat stroke, which can lead to dementia. We also encourage the use of hearing aids. Hearing aids allow people to be more socially and cognitively engaged and are thought to help prevent dementia.
“We need to assess the enormity of the problem,” said Alexa Beiser, a professor of biostatistics at Boston University School of Public Health, who is not involved in the new study but is an independent reviewer for the journal. Evaluated. “The risk is enormous and it's not evenly distributed among people,” Dr. Beiser added, noting that the study found that black Americans were at disproportionate risk.
Researchers evaluated more than 30 years of data from a longitudinal study of the health of people in four communities in Maryland, Mississippi, Minnesota, and North Carolina. Dr. Koresh said about 27% of the 15,000 participants were black, primarily from Jackson, Michigan. The analysis was funded by the National Institutes of Health and focused on black and white participants because there were fewer participants from other racial and ethnic groups, the authors said.
The study estimates that the annual number of new infections among black people will jump from about 60,000 in 2020 to about 180,000 in 2060. The primary reason the number of new infections among black Americans has tripled is because the proportion of black Americans living to the highest ages is decreasing. According to Dr. Koresh, they are growing faster than whites.
In this study, black participants developed dementia at a younger average age and had a higher lifetime risk than white participants.
Dr. Koresh noted that high blood pressure, diabetes, and high cholesterol increase the risk of dementia, adding, “I don't know if we fully understand it, but at least some of it is due to vascular risk factors.” That means it's more common.” She said it's not just structural racism that affected health, but also the study participants' lower socio-economic status and education levels.
Predicting dementia risk is complex for several reasons. The causes of dementia are varied and often not fully understood. There are many different types of dementia, and some may overlap with each other. The new analysis, like several other studies, did not attempt to estimate the number of people who develop Alzheimer's disease, the most common type of dementia. That's because many experts believe aspects of Alzheimer's disease can overlap with vascular dementia, and both conditions can be fueled by cardiovascular problems, Dr. Koresh said. said.
Several studies conducted in the United States and around the world have found that the proportion of older adults with dementia has decreased in recent years. This is likely due to improved treatment of cardiovascular disease and a more educated population, as education improves brain resilience and overall health.
The reduction is consistent with the new study, experts and authors said, because the study estimates people's current level of cumulative dementia risk over their lifetime and projects it into the future. For example, positive changes such as healthier behaviors and better treatments for conditions such as diabetes and stroke may reduce risk rates at any age over the next few decades, but new The number of infected people will be higher than it is now. According to experts, the elderly population is increasing, reaching 514,000 people.
“Whether it's 1 million people a year or 750,000 people a year, the population is going to get bigger, and the longer people live, the more dementia we're going to have.” said Dr. Beiser. Lower estimates were found.
The study also found that women had a higher lifetime risk of dementia than men: 48% compared to 35%. Dr. Koresh said the main reason for this was that the women in the study lived longer. “As more people approach their 95th birthday, the risk of developing dementia by the time they reach their 95th birthday is higher,” he said.
Langa said other researchers believe there are biological differences that increase women's risk, perhaps “the hormonal environment within the body, or underlying factors that may affect women's brains differently than men's.” He said he is trying to find out whether there are “genetic differences.”
Another high-risk group is people with two copies of the APOE4 gene variant, which increases the risk of Alzheimer's disease and the disease at a younger age compared to people without the variant. significantly increases the risk of developing. In this study, people with two copies of APOE4 had a lifetime risk of dementia of 59%, compared to a lifetime risk of 48% for people with one copy of APOE4, and a lifetime risk of 48% for people without the mutation. was 39%.
The analysis used health data from the Atherosclerosis Risk in Communities Study (known as ARIC) for people aged 55 and older from 1987 to 2020.
Researchers used several methods to determine if and when participants developed dementia. About a quarter of the cases were diagnosed through in-person neuropsychological testing, while others were identified through hospital records, death certificates, or telephone assessments. Experts say each method has limitations and could lead to overestimation or underestimation of the actual number of people with dementia.
The study found that the risk of dementia at age 75 is about 4 percent. At age 85, it was 20%. And at age 95, it was 42 percent. The researchers applied the risk percentages to population projections from the census to estimate future annual dementia diagnoses.
To reduce the chance of developing dementia, experts and study authors emphasized taking steps to address known risk factors such as diabetes, high blood pressure, and hearing loss. A recent report from the Lancet Commission on Dementia lists 14 modifiable risk factors, stating that “half of dementia risk is preventable, and it is never too early or too late to address dementia risk.'' “Not too much,” Dr. Koresh said.
Experts recommended such measures instead of searching for new drugs for Alzheimer's disease. The new drugs appear to only be able to slightly slow cognitive decline in the early stages of the disease, but they also carry safety risks.
Dr Langa said of the new drugs: “We do not believe they will have a significant effect on reducing lifetime risk because their efficacy is relatively limited.” “I think there is a higher return from public health and lifestyle interventions that improve overall health and appear to reduce the risk of dementia over time.”
