By Dr. Rob Winningham, Psychology and Gerontology Professor at Western Oregon University
You may have seen headlines such as:
- CBS News: Dementia Cases Worldwide to Triple by 2050
- The Guardian: Middle-Age Obesity Will Lead to a Surge in Dementia Cases
- BBC News: Experts Predict Dementia Epidemic
While it is true that the overall number of dementia cases will increase in the United States and elsewhere in the coming years, that isn’t the whole story. The headline you don’t often see is that the proportion of older adults with dementia is actually decreasing. To understand this, we need to define a couple of terms epidemiologists (people who study disease and health in populations) use to describe health trends in the population.
1. Prevalence – proportion of the population with a particular condition
2. Incidence – the number of cases in a given time period
For example: the incidence of people wearing cowboy hats in Los Angeles, California, is much higher than it is in Bandera, Texas. While Bandera is called the Cowboy Capital of the World, there are only 856 people who call it home. Los Angeles, however, has almost 4 million people. If only 1 in 30,000 people in Los Angeles wore a cowboy hat, they would still have a higher incidence, even though the proportion of people wearing cowboy hats is much lower.
It is true that the incidence or the number of new cases of dementia is increasing because we now have more older adults and people are living longer. In the past decade, the number of people with dementia in the United States has increased by over 1 million, and that sounds kind of scary. But the prevalence or the proportion of the population in the United States and Western Europe has actually decreased! A 2013 study published in the journal Lancet reported that the percentage of people 65 and older with dementia has plummeted 25% in the past 20 years from 8.3% to 6.2%. Similar results have been measured in the United States.
Why has the prevalence or proportion of people with dementia gone down so much? We don’t know for sure, but it could be a combination of lifestyle changes and medical advances.
- Controlling cardiovascular risk factors with cholesterol and blood pressure screenings
- Better education and possibly more cognitive stimulation
- Greater awareness of the importance of physical exercise
- Greater awareness of the importance of good nutrition, omega-3 fatty acids, and diet
It appears that the increased awareness of how lifestyle affects our health might already be affecting dementia rates, but we still have a long way to go. We could further reduce dementia and delay its onset by doing the things that we know can maximize memory ability. We haven’t discovered a magic drug to prevent dementia yet, but we are making progress in finding some of the controllable factors that matter.
Have a wonderful August,
~ Jamie Lanners, Boulder Creek Housing Manager