The number of people who develop dementia in the United States each year over the next 35 years will double to about 1 million annually by 2060. New study It is estimated that the number of new cases annually among black Americans will triple.
This increase will be due primarily to an aging population, with many Americans 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. Getting older is the biggest risk factor for dementia. The study found that the vast majority of dementia risks occurred after the age of 75, and it increases further as people reach the age of 95.
the study, It was published Monday in the journal Nature MedicineIt found that adults over the age of 55 had a 42 percent lifetime risk of developing dementia. This is much higher than previous lifetime risk estimates, a finding that the authors attributed to updated information about Americans’ health and longevity and the fact that their study population was more diverse than a number of previous studies, which included primarily white participants.
Some experts said estimates of the new lifetime risks and the expected increase in annual cases may be too high, but they agree that dementia cases will rise in the coming decades.
“Even if the rate were much lower than that, we would still see a significant increase in the number of people, family and societal burdens of dementia due to the growth in the number of older adults, both in the United States and in the United States.” “It’s relevant in the United States and around the world,” said Dr. Kenneth Langa, a professor of medicine at the University of Michigan, who has researched dementia risk and was not involved in the new study.
Dementia has already taken a huge toll on American families and the nation’s health care system. More than six million Americans currently suffer from dementia, Nearly 10 percent of people 65 and olderresearch found. Experts say that dementia kills more than 100,000 people every year in the United States and costs more than $600 billion in care and other costs.
Dr. Joseph Koresh, director of the Institute for Optimal Aging at New York University’s Grossman School of Medicine and head of the study, which included about 100 researchers at 10 universities, said.
Researchers and other experts said the study reinforces the urgent need to try to prevent or slow the onset of dementia. Their main recommendations are to improve people’s cardiovascular health through medications and lifestyle changes; Increase efforts to prevent and treat strokes, which can lead to dementia; and encouraging people to wear hearing aids, which appears to help prevent dementia by allowing people to be more socially and cognitively engaged.
“One needs to see the sheer scale of the problem,” said Alexa Pizer, a professor of biostatistics at Boston University School of Public Health, who was not involved in the new study but evaluated it as an independent reviewer for the journal. “It’s enormous, and it’s not evenly distributed among people,” Dr. Beiser added, noting that the study found disproportionate risks for black Americans.
The researchers evaluated more than three decades of data from a long-term study of people’s health in four communities — in Maryland, Mississippi, Minnesota and North Carolina. About 27 percent of the 15,000 participants were black, most of them from Jackson, Miss., Dr. Koresh said. The analysis, which was funded by the National Institutes of Health, focused on black and white participants because there were not many participants from other racial and ethnic groups, the authors said.
The study estimated that the number of new annual cases among blacks will rise to about 180,000 cases in 2060 from about 60,000 cases in 2020. The main reason for the tripling of new cases among this population is that the percentage of black Americans who live to the oldest ages, said Dr. Koresh said the growth rate is growing faster than among white people.
In the study, black participants also developed dementia at younger average ages than white participants and had a higher lifetime risk.
“I don’t know that we fully understand it, but at least some of the contributing factors are that vascular risk factors are more common,” Dr. Koresh said, noting that high blood pressure, diabetes, and high cholesterol increase the risk of dementia. He said lower socioeconomic status and education levels among study participants may also have played a role, as well as structural racism that affected health.
Predicting dementia risk is complex for several reasons. The causes of dementia vary and are often not fully understood. Types of dementia also vary and can overlap with each other. The new analysis, like many other studies, did not attempt to estimate how many people might 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 that both conditions can be fueled by cardiovascular problems, Dr. Koresh said.
Many studies in America and the world have found a high incidence of dementia among the elderly It has declined in recent yearsmost likely due to better treatment of cardiovascular problems and increased education of the population, because education can improve brain plasticity and overall health.
The experts and authors said that this decrease does not contradict the new study, because the study estimated the current level of cumulative dementia risk over people’s lives and projected it forward. Positive changes — healthier behaviors and better treatment for conditions like diabetes and stroke, for example — could lower the risk rate at any given age in the coming decades, but the number of new cases each year would still exceed the current number. Experts said that 514,000 due to the growing number of elderly people.
“Whether it’s 1 million people or 750,000 people a year, there are going to be a lot of people, and the longer people live, the more cases of dementia there are,” said Dr. Pizer, who worked on the research. Previous studies Of different patients found lower estimates.
The study also found that women had a higher lifetime risk of developing dementia than men, 48% compared to 35%. This is primarily because the women in the study lived longer, Dr. Koresh said. “Their risk of developing dementia by their 95th birthday is higher because more of them will be closer to their 95th birthday,” he said.
Dr. Langa said other researchers are trying to figure out whether there are also biological differences that increase the risk of developing the disease in women, perhaps “the hormonal environment in the body or even possible genetic differences that may affect women’s brains in different ways than men’s brains.”
Another group at risk were people with two copies of the APOE4 variant gene, which greatly increases the risk of developing and developing Alzheimer’s disease at a younger age than people without this variant. In the study, people with two copies of APOE4 had a lifetime risk of dementia of 59% compared with a lifetime risk of 48% for people with one copy and 39% for people without the variant.
The analysis used health data from the Atherosclerosis Risk in Communities Study (known as ARIC), which follows people ages 55 and older from 1987 to 2020.
Researchers used several methods to determine if and when participants developed dementia. About a quarter of cases were diagnosed through in-person neuropsychological testing, while others were identified through hospital records, death certificates, or through telephone assessments. Experts said that each method has limitations, which may lead to overestimating or underestimating the actual numbers of dementia patients.
The study found that at age 75, the risk of developing dementia was about 4 percent; At age 85, the proportion was 20%; At age 95, the percentage was 42 percent. The researchers applied the risk ratio to population projections from the census to estimate future annual dementia diagnoses.
To reduce the chances 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 issued by Lancet Commission on Dementia It listed 14 risk factors that could be improved, concluding that “half of the risk of dementia is preventable, and it is neither too early nor too late to address the risk of dementia,” Dr Koresh said.
Experts recommended such steps rather than searching for new drugs for Alzheimer’s disease, which appear to be able to only modestly slow cognitive decline in the early stages of the disease and which carry safety risks.
“Because of their relatively limited efficacy, I don’t think you’re going to get much success in reducing lifelong risks from this,” Dr. Langa said of the new drugs. “I think we will get more money from some of the public health and lifestyle interventions that appear to improve overall health and reduce the risk of dementia over time.”