Accurate dementia rates are difficult to quantify. Some studies indicate numbers are rising, while others show they are not. Meanwhile, modern studies and evidence suggest that many factors, such as stress, genes, and lifestyle – all play a role in how dementia begins and progresses.
Age-specific dementia rates are not dropping everywhere around the world. While Alzheimer's Disease International states that less than 2 percent of people aged 65 to 69 have dementia, this figure dramatically rises with age. For example, 5 percent of those aged 71 to 79, 24 percent of those 80 to 89, and 37 percent of those over 90 have dementia. The World Health Organization predicts that the number of people who have dementia worldwide will increase from 47.5 million to 75.6 million by 2030.
"Less than 2 percent of people aged 65 to 69 have dementia."
Problems with current research highlighting declining dementia rates
A study published in the New England Journal of Medicine on Feb. 11, 2016, titled "Is Dementia in Decline? Historical Trends and Future Trajectories," used data from the Framingham Heart Study to chart the medical history of over 5,000 people in a Massachusetts city. The researchers discovered that dementia rates had decreased by 44 percent in the past four decades. Additionally, the research indicates the average age people begin showcasing symptoms of dementia rose from 80 years old in the 1970s to 85 today.
While this results should be promising, critics of the study – and even the researchers themselves – pointed out that the sample was from a predominantly white population. Meanwhile, the decline was only seen in those with at least a high school education and who already reported to be in better health.
The authors of the study did concede that further studies need to expand their reach to other demographics. Researchers also did not explore how factors such as how changes in exercise and diet could affect the start or progression of dementia. However, they did consider medical conditions, education and smoking.
"Our study offers hope that some of the dementia cases might be preventable – or at least delayed – through primary (keep the disease process from starting) or secondary (keep it from progressing to clinically obvious dementia) prevention," corresponding author Sudha Seshadri, professor of neurology at MED and FHS senior investigator, explained to Boston University's School of Public Health. "Effective prevention could diminish in some measure the projected explosion in the number of persons affected with the disease in the next few decades."
"Dementia rates had decreased by 44 percent in the past four decades."
A more inclusive view of dementia rates in America
Another study, published the day before in the Alzheimer's and Dementia journal, titled "Inequalities in dementia incidence between six racial and ethnic groups over 14 years," examined the health records of over 274,000 Kaiser Permanente healthcare members among six racial and ethnic groups. These researchers determined that African Americans and Native Americans/Alaskan Natives were disproportionately affected by dementia.
The annual rate of dementia for white people was 19.4 per 1,000 cases, while it was 26.6 in 1,000 people for African Americans and 22.2 cases every 1,000 people for Native Americans/Alaskan Natives. The other racial and ethnic groups were Asian Americans and Latinos. These researchers predict that 38 percent of African Americans and 35 percent of Native Americans/Alaskan Natives over 65 will develop dementia in the next 25 years. The other demographic rates are expected to increase as well.
While we are still struggling to understand precisely what causes dementia and how to reduce our risks, we must proactively seek out new ways to improve the quality of care of our residents with dementia. To learn more about dementia care training and how to support your residents, contact Mariposa Training or take one of our comprehensive courses today!