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The Curious Case of Declining Dementia

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Authored by Saeculum Research

According to a recent study published in The New England Journal of Medicine, the incidence of dementia has fallen 20 percent per decade since 1975. This finding is the latest piece of evidence gathered over the last 10 years suggesting that dementia may not be the looming health crisis everyone thought it would be.

Although this health trend could reduce the sky-high cost projections associated with rising prevalence by age, there is a chance that both the cost and prevalence could continue to surge. Why? The studies in question largely focus on the dementia rates of pre-Boomer generations, who are known for their positive health trends. As Boomers continue to pass age 65, their health outlook may be more uncertain. This generation’s unhealthy lifestyle trends could also reveal a widening rift between the rich and poor that will affect our nation’s health care system for many years to come.

The latest report shows a progressive decline in the incidence of dementia over the last three decades. Using data from the Framingham Heart Study (FHS), researchers found that the five-year age- and sex-adjusted cumulative hazard rates for dementia among indi­viduals age 60 and older fell from 3.6 per 100 persons between 1977 and 1983 to 2.0 per 100 persons between 2004 and 2008. This downtrend was strongest in vascular dementia rates, which are linked to improved cardiovascular health. Although Alzheimer’s disease (the most common form of dementia) rates also declined, the trend narrowly missed what researchers consider to be statistically significant.

This study joins a growing body of research suggesting that dementia rates are falling.In 2005, researchers at Duke University examined data from the National Long-Term Care Surveys and found that the prevalence of severe cognitive impairment in the Medicare population decreased 42 percent between 1982 and 1999. In 2008, re­searchers at the University of Michigan examined data from the Health and Retirement Study and found that the prevalence of cognitive impairment among those ages 70 and older fell from 12.2 percent in 1993 to 8.7 percent in 2002. And at last year’s Alzheimer’s Association Inter­national Conference, Carol Derby of the Albert Einstein College of Medicine pres­ented evidence indicating that those born after 1930 have a lower risk of developing dementia than those born between 1916 and 1930—seemingly declining by generation.

Why is this happening? Healthier individuals are less likely to incur demen­tia. Over the past decade, the oldest age brackets have been less likely to develop chronic conditions (that put them at increased risk for dementia) than previ­ous generations at the same age. In the most recent FHS, researchers noted that improved cardiovascular health reduced vascular dementia rates—a promising development considering that diet and exercise significantly improves cardio­vascular health. Other studies have unearthed similar health trends. Al­though researchers are split on whether obesity reduces one’s risk for demen­tia or not, they have linked smoking, depression, and diabetes to increased dementia risk. Meanwhile, other indi­cators such as head trauma, alcohol abuse, and HIV are risk factors for early-onset dementia.

Researchers have also discovered a link between education and dementia—another trend that has improved from one generation to the next. According to FHS researchers, the decline in the incidence of dementia was limited to participants with a high school diploma. (Researchers dichot­omized education by those with and without a high school diploma—they did not draw conclusions based on whether or not participants had college degrees.) In the past, re­searchers have made similar connections between education and better health outcomes. According to one study, higher levels of education (and net worth) were associated with significantly lower odds of cognitive impairment between 1993 and 2002. Education also plays a role in life expectancy—and may even have a direct effect on an individual’s longevity. (See: “The Future of Longevity.”) This would explain why the average age of diagnosis in the FHS rose from 80 to 85.

This is great news because it means that the cost of dementia might not skyrocket as much as previously projected. In 2013, RAND Corporation estimated that the direct and indirect costs of dementia totaled between $159 and $215 billion—a number that could hit as much as $511 billion by 2040. But when making these projections, researchers assumed that prevalence by age would remain the same as Boomers entered the upper age brackets. If prevalence is in fact declining by age, then these cost projections should be more manageable.

But the future might not be as bright as it appears. These studies are largely meas­uring the educational and health improvements made by pre-Boomer generations. While the Lost Generation grew up working in child sweat shops, the G.I. Generation came of age with the sharpest rise in school achievement ever recorded. And thanks to vitamins and vaccines, G.I.s and Silent had health advantages over their parents and grandparents as well.

Looking ahead, the Boomer experience may be less certain. On the one hand, Boomers could continue this positive trend. Their educational advantage could work in their favor. On the other hand, Boomers could reverse course. As we have discussed before (See: “Boomer Malaise”), the lifestyle behaviors of Boomers are fueling a surge in pre-existing health problems. This generation is bringing higher rates of obesity, diabetes, and hypertension with them into old age—conditions that dementia experts warn could undermine the gains achieved through improved education, wealth, and control of vascular risk factors.

What’s more certain—and more worrisome—is the growing split we are likely to see between high-SES and low-SES Boomers. Whether dementia rates continue to improve or reverse for Boomers as a whole, it’s very likely that the rates will diverge by socio­economic status. Although the prevalence rate will likely fall for the well-educated (and often more affluent), it will continue to rise for the less-educated (and less affluent). Like so many other health issues (see: “The Aging of Aquarius”), dementia is highly correlated with the life histories and chronic diseases that put low-SES Boomers at greater risk. This rich-poor gap may be revealed over time by the declining mental function of late-wave Boomers, who are not as educated and not as healthy as first-wavers.

Although dementia rates are improving rapidly for older generations, the jury is still out for Boomers. And whether dementia rates improve in their lifetime or not, we will very likely notice a growing class divide in dementia outcomes that parallels a similar divide in other health outcomes for this generation. While affluent, educated Boomers with close families and healthy lifestyles will be less likely to be afflicted by dementia, non-affluent, uneducated Boomers living on their own with less healthy lifestyles will be more likely to experience cognitive impairment—a schism that will exert major pressure on public policy and budgets alike in the years ahead.

 


Takeaways

  • Dementia rates have fallen over the last three decades, but this might not be the case for long. According to mounting research, prevalence rates by age have declined thanks to improved health and educational outcomes. At first glance, these findings suggest that pre­vious cost projections associated with dementia should be reduced. A closer look, however, reveals that these studies are actually measuring the health and education improvements of pre-Boomer generations. Although Boomers’ educational advantages may stave off cognitive impairment, their unhealthy habits could raise rates once again. And like many other Boomer health trends, there will likely be a growing rich-poor gap among the afflict­ed, which will have long-lasting impli­cations for our nation’s health care system.
  • Prevention may be a cure to Alzheimer’s. According to Time cover story from February, scientists’ search for an Alzheimer’s cure has largely focused on removing the beta-amyloid plaque associated with disease. Al­though scientists have cured Alzheimer’s in mice multi­ple times through this method, they have yet to replicate those results in humans. While scientists are starting to take new approaches to find a cure, others are recom­mending preventative measures. Leading expert Dr. P. Murali Doraiswamy is confident that people who track cardiovascular markers (blood pressure, blood sugar, and BMI) and modify their behavior (through diet and exercise) can prevent memory loss.
  • “Managing” dementia is an expensive alter­native to a cure. The cost of dementia isn’t just due to prevalence; it also depends on what treatment options are available and how much Boomers insist on using them. The cheap­est future is one in which scientists either discover a miracle cure or make no progress at all. The most expen­sive future is the one in which we deve­lop effective treat­ments designed to “manage” dementia. Current treat­ment options don’t do a lot—they only slow mental decline during the early stages of the disease. But future treatments designed to help people who need care 24/7 live longer could make costs soar.
  • Dementia will be a global epidemic. As fertility rates fall and people live longer, the global prevalence of dementia will increase. Large societies like China, which will have a considerable elderly population before exper­iencing income or educational gains, will likely be hit hardest. As this epidemic spreads, coun­tries will have to accommodate a growing population suffering from memory loss. London has trained police officers, fire­fighters, and bus drivers to spot signs of dementia. And in Holland, “Dementia Village” is a retirement commu­nity of sorts where doctors and caregivers are disguised as cashiers and mailmen to check in on patients outside of a stress-inducing medical setting.

 

 

Material posted on this website is for informational purposes only and does not constitute a legal opinion or medical advice. Contact your legal representative or medical professional for information specific to your legal or medical needs.

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