New Research Forecasts Dementia Cases in United States Will Double by 2050
Experts attribute the rise in cognitive decline to an aging population, as well as risk factors such as smoking, obesity, and high blood sugar.
By 2050, the number of U.S. adults over 40 living with dementia is projected to rise from 5.2 million people to 10.5 million, according to a new analysis. Published on January 6 in The Lancet, the study predicts that the number of people with dementia will go up in every country in the world, resulting in a near tripling in the global rate of dementia.
The anticipated increase is primary due to population growth and population aging, though the authors highlight the impact of 4 risk factors for dementia — smoking, obesity, high blood sugar, and low education, and how addressing those factors might improve the forecast.
The projected increase in the prevalence of dementia in the United States is likely to be accurate, says Maryjo Lynn Cleveland, MD, a geriatric physician who specializes in dementia at Atrium Health Wake Forest Baptist in Winston Salem, North Carolina, and was not involved in this report.
“The four risk factors the article references are extremely important risk factors to intervene on to attempt to bend the curve. Other risk factors, such as hearing loss, mid-life hypertension, depression [or] social and isolation, and physical inactivity also likely play a role,” says Dr. Cleveland.
Although Common, Dementia Is Not a Normal Part of Aging
Dementia is the loss of cognitive functioning, which includes things like the ability to think, remember, and reason, to the point where it interferes with a person’s daily life, according to the National Institute on Aging.
Types of dementia include Alzheimer’s disease, Lewy body dementia, vascular dementia, and Parkinson’s disease, per the Centers for Disease Control and Prevention (CDC).
The condition becomes more common as people get older — it’s estimated that about 1 out every 3 people over the age of 85 have some form of dementia — but it’s not a normal part of aging.
Signs and symptoms of dementia can include forgetting the names of close family members or friends, getting lost in a familiar neighborhood, and using unusual words to refer to objects, according to the CDC.
Dementia More Common in Women Than Men, a Trend That’s Expected To Continue
In 2019, there were more women dementia cases as compared with men, and the analysis suggests that pattern will continue in 2050. While part of that difference can be attributed to women living longer than men, per the World Health Organization, there seem to be other factors at play, said coauthor Jaimie Steinmetz, PhD, managing research scientist at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle, in a IHME release.
“There is evidence of sex differences in the biological mechanisms that underlie dementia. It’s been suggested that Alzheimer’s disease may spread differently in the brains of women than in men, and several genetic risk factors seem related to the disease risk by sex,” said Dr. Steinmetz.
Countries With the Highest and Lowest Projected Increases in Dementia
According to the study authors, the biggest increases in prevalence will occur in sub-Saharan Africa, North Africa, and the Middle East, mostly as a result of population growth.
These are the countries with the highest projected percentage change in total number of dementia cases from 2019 to 2050:
- Qatar, 1926 percent
- United Arab Emirates, 1795 percent
- Bahrain, 1084 percent
- Oman, 943 percent
- Saudi Arabia, 898 percent
The authors predict the smallest increases will be in higher income countries in the Asian Pacific, which they attribute to preventative measures, including improvements in education and healthy lifestyles.
These are the countries with the lowest projected percentage change in total number of dementia cases from 2019 to 2050:
- Japan, 27 percent
- Bulgaria, 37 percent
- Serbia, 38 percent
- Lithuania, 44 percent
- Greece, 45 percent
Up to 40 Percent of Dementia Cases May Be Prevented or Delayed by Elimination Of Risk Factors
Even small advances in preventing dementia or delaying its progression would pay remarkable dividends, said lead study author Emma Nichols, PhD, researcher at the Institute for Health Metrics and Evaluation (IHME) in the release.
“To have the greatest impact, we need to reduce exposure to the leading risk factors in each country. For most, this means scaling up locally appropriate, low-cost programs that support healthier diets, more exercise, quitting smoking, and better access to education,” said Dr. Nichols. It also means continuing to invest in research to identify effective treatments to stop, slow, or prevent dementia, she added.
Although this study focused on four risk factors for dementia, a paper published in July 2020 in The Lancet suggested that as many as 40 percent of all dementia cases could be prevented or postponed if 12 known risk factors were eliminated. These included the ones addressed in the 2050 projection — low education, smoking, and obesity — as well as hearing impairment, depression, physical inactivity, diabetes, high blood pressure, social isolation, excessive alcohol consumption, head injury, and air pollution.
Expert Tips on Delaying the Onset of Dementia
Cleveland agrees that it’s likely that lifestyle modification may play a significant role in at least delaying the onset of cognitive impairment. Although there currently isn’t any hard evidence to recommend any dietary supplements to delay dementia, there are ways to improve your health and potentially reduce your risk, she says.
“I instruct my patients to get 150 minutes of moderate intensity exercise per week, to adhere to a Mediterranean style diet, to ensure good sleep, and to be as socially active as is possible these days. It’s also important to “know your numbers” for blood pressure, weight, BMI, and cholesterol, and try to bring these into a normal range,” she says.