En español | In just three decades, more than 152 million people across the globe may be living with dementia, with the highest increases in prevalence occurring in some of the world's poorest regions, according to new data presented July 27 at the Alzheimer's Association International Conference. Currently, about 50 million people worldwide have dementia.
"The numbers are staggering,” Heather Snyder, vice president of medical and scientific relations at the Alzheimer's Association, says in a statement. “To put that in context, that number is equal to approximately half of the U.S. population in 2020."
Several factors fuel this forecast. Here's a look at why dementia cases could skyrocket in the next 30 years.
10 Ways to Reduce Your Risk for Dementia
Research shows that adopting healthy lifestyle behaviors helps the brain and could reduce your risk for dementia. Among them:
- Exercise regularly.
- Don't smoke.
- Get your blood pressure under control.
- Limit your alcohol intake.
- Eat heart-healthy foods — especially those in the MIND-DASH diets.
- Keep your brain active and intellectually stimulated.
- Protect your brain from head injury: Wear your seat belt and bike or motorcycle helmet.
- Get good sleep.
- Take care of your mental health.
- Stay socially engaged.
Source: National Institute on Aging, the Alzheimer's Association, AARP's Global Council on Brain Health
1. An aging population
The underdeveloped regions of sub-Saharan Africa, North Africa and the Middle East are likely to suffer the brunt of the increase, says Emma Nichols, a researcher with the Institute for Health Metrics and Evaluation, an independent research center at the University of Washington School of Medicine, who presented her research at the Alzheimer's conference.
"This indicates the magnitude of the problem we can expect in places where there is a lack of infrastructure to handle the care that might be needed by individuals with dementia,” Nichols tells AARP.
Nichols used the 2019 Global Burden of Disease study to project the change in worldwide dementia rates from 2019 to 2050.
• North America, Western Europe and Australia will see the smallest changes, with increases of 20 to 80 percent.
• In the Middle East and Africa, cases will soar anywhere from 200 to 2,000 percent above 2019 numbers.
Most of the projected surge is tied to the ever-increasing population of older adults. By 2050, 16 percent of the world's population will be 65 and older — up from 8 percent in 2010, according to the National Institute on Aging. This change is driving up dementia numbers everywhere; the strongest known risk factor for dementia is increasing age.
Nichols also estimates that 1.55 million people worldwide died from dementia in 2019. There were almost twice as many deaths in women as in men (1.02 million compared to 540,000).
"The numbers emphasize the vital need for research focused on the discovery of disease-modifying treatments and effective low-cost interventions to prevent dementia or delay its onset,” Nichols says.
2. Obesity and chronic diseases contribute to climb in numbers
There is a bright spot in the new findings: Improved education is expected to reduce the anticipated increase in dementia by about 6.2 million cases. Unfortunately, increases in smoking, obesity and high blood sugar will undercut that gain, contributing to 6.8 million cases worldwide.
"That says a lot about risk factors and a lot about prevention,” Nichols tells AARP, noting that positive lifestyle changes have been shown to reduce dementia risk.
These same lifestyle and chronic disease risk factors fuel Alzheimer's mortality rates in the United States. This is particularly true in the rural eastern south-central region, where Alzheimer's mortality is three times as high as in the urban mid-Atlantic, said Ambar Kulshreshtha, M.D., assistant professor of family and preventive medicine at Emory University, who also presented his research at the Alzheimer's conference.
"This isn't surprising,” he tells AARP. “The rural South always has a higher burden of disease in many conditions, including stroke and heart failure. There are also issues with poor diet and access to care. It's probably all of these factors making the difference in mortality."
Kulshreshtha and his team used data from the National Center for Health Statistics to examine Alzheimer's death rates from 1999 to 2019. Over that period, Alzheimer's-related death rates increased by 88 percent, from 16 to 30 per 100,000 people.
The investigators saw stark contrasts in the numbers, too. Mortality rates were highest in the eastern south-central region, including in Alabama, Kentucky, Mississippi and Tennessee. In this region, 274 people out of every 100,000 among those older than 65 died from Alzheimer's. The rate in the mid-Atlantic region was 86 per 100,000.
The study didn't delve into the reasons for these disparities. There are probably multiple factors, says Kulshreshtha, including less access to primary and specialist medical care and more chronic conditions like high blood pressure, diabetes and heart disease — all of which are highly prevalent in the rural areas in the South and which increase the risk of Alzheimer's.
The good news is that people can reduce their risk of these contributing illnesses, thereby also reducing their risk of Alzheimer's disease, Kulshreshtha says. “My main message is that we need to pay attention to prevention. Healthy eating habits and an active lifestyle reduce the risk for many diseases, including Alzheimer's."
AARP's Global Council on Brain Health has released several science-based reports that look at the impact various lifestyle factors, such as blood pressure, sleep and socialization, have on brain health. More information on these reports, including tips for keeping your brain healthy, is available on the group's website.
3. Younger cases add to increasing numbers
While older age is the largest risk factor for dementia, younger people can also develop these diseases, says Stevie Hendriks, a graduate student at Maastricht University in the Netherlands, who also presented her findings at the Alzheimer's conference. She and her colleagues reviewed 50 studies (42 were included in the meta analysis) and found that about 10 of every 100,000 people younger than 65 will develop some form of dementia each year. This translates to about 350,000 younger-age onset cases worldwide every year.
Unfortunately, she tells AARP, that number is probably a vast underestimate: “In our study, we didn't have a lot of information on the incidence in Africa, Asia and some other low-income countries. So, we believe this incidence of young people with dementia might even be higher."
The biggest increase among this younger population will be in Alzheimer's cases, Hendriks says. She also projected increases in vascular dementia, which is largely related to cardiovascular disease, and frontotemporal dementia, a group of uncommon disorders affecting the frontal or the temporal lobes of the brain — the seat of personality and thought.
Younger-onset dementias are particularly difficult to diagnose, Hendriks notes, “because physicians don't necessarily think ‘dementia’ when they see symptoms in a relatively young person.” Symptoms in younger people can also be very different from those in older people.
"Going without a diagnosis can be really hard, because many patients have a lot of personality changes. They can become aggressive or very, very angry, losing their jobs and losing relationships with partners and children,” says Hendriks, who hopes her research raises awareness and improves the diagnostic process in younger adults with dementia.
Latest research raises need for prevention efforts, treatments
The studies highlight the pressing need for effective preventive strategies and for treatments that will slow disease progression, says Maria Carrillo, chief science officer of the Alzheimer's Association.
"Without effective treatments to stop, slow or prevent Alzheimer's and all dementia, these numbers will continue to grow beyond 2050 and continue to impact individuals, caregivers, health systems and governments globally,” she says in a news release.
"In addition to therapeutics, it's critical to uncover culturally tailored interventions that reduce dementia risk through lifestyle factors like education, diet and exercise."