American College of Physicians: Internal Medicine — Doctors for Adults ®

Tuesday, December 27, 2016

Declines in dementia, of hearts and minds

In this season when we are meant to be thankful, but when so many of us have had so many reasons to be otherwise, we have received a timely, welcome bit of universally good news. Rates of dementia in the United States appear to be declining.

This news reaches us courtesy of a study published recently in JAMA Internal Medicine. The investigators used standard, validated measures of cognitive function and dementia in two groups of more than 10,000 people in the U.S. with an average age of roughly 75 in the year 2000, and again in 2012. The overall rate of dementia declined over that span from 11.6% to 8.8%.

Taking this news at face value, it is extremely encouraging. There have been rather dire projections that with the population in the U.S. and other developed countries aging, rates of dementia would rise in tandem. Alzheimer's and related conditions are devastating, obviously, so the human cost of such a rise- imposed on victims of the condition and their caregivers alike- is the principal concern. But these projections also pertain to the financial devastation wrought by a tidal wave of dementia-related healthcare costs crashing into a system already drowning in the costs of chronic disease.

Expecting dementia rates to rise and seeing them fall is simply good news. But inevitably, the whole story is not quite so simple.

For one thing, projections about a rise in dementia rates do relate directly to aging of the population, while this study matched its cohorts for average age. In fact, the mean age of the 2012 cohort was slightly less than the earlier group, although from a statistical perspective that were nearly equivalent. Still, the 2012 cohort certainly was not older- and it is the increase in numbers of ever-older people that was predicted to drive an increase in dementia rates. So, what if we compared a cohort of 10,000 people now with a mean age of 80, to a cohort from a decade ago with a mean age of 75?

The new study does not answer this question. The more recent study cohort did have more people over age 85 than the earlier cohort, even though the average age of the group was trivially lower, not higher. The study methods did include adjustment for age, and the decline in dementia over time remained significant. So, the good news here appears to be fairly robust- but not robust enough to preclude the feared increase in the prevalence of dementia as the mean age of the population ascends.

The basic finding of this study begs the obvious question: why? The only obvious explanation the study itself contributes is education. The more recent study cohort had significantly more educational attainment than their predecessors from a decade ago. Because this is an observational study, and not an intervention designed to establish cause and effect, it can only tell us that more years of education appear to be associated with less risk of dementia in older age.

This association is certainly plausible. Much prior research suggests that the brain, like the body, is subject to the “use it or lose it” adage. Education is brain exercise, and plausibly defends against what we might call “cognitive atrophy.” That much more so if more education in turn leads to more intellectually demanding work. The study suggests that is likely, as average income and socioeconomic status were significantly higher in the more recent study group. Whatever the direct benefits of education, the indirect benefits over time of more opportunity, more security, and more mental stimulation on the job and perhaps off as well, are apt to be greater.

This finding is promising, since education in our population is something we have the capacity to modify. The advantages to raising population-wide, average educational attainment are diverse and compelling, but that much more so if reducing the lifetime risk of dementia is in the mix. But, this finding is concerning as well. A shift in social priorities away from investments in education and the reduction in disparities that prevail in that area could certainly threaten to reverse the favorable trend.

The paper notes other associations of interest, if not of entirely obvious meaning. Rates of diabetes, heart disease, and obesity were higher, not lower, in the more recent cohort; rates of dementia were lower despite these liabilities, as was the rate of impaired daily function. This might be testimony to the power of modern medical treatment. Newer, better drugs and procedures do very little to prevent cardiometabolic risk factors or the diseases associated with them, but do defend robustly against their dire complications, such as heart attack, stroke, premature death, and perhaps- dementia.

Ironically, this paper is almost entirely silent on the topic long known to have the greatest potential to prevent dementia, namely, lifestyle. The word itself does not appear in the paper at all. Exactly one line in the discussion refers to diet and physical activity, in parentheses, when the authors note that: “Higher levels of educational attainment are also associated with health behaviors (e.g., physical activity, diet, and smoking) … which may play a role in decreasing lifetime dementia risk.”

Dementia of the Alzheimer's type, and related vascular dementia, are generally regarded as close cousins to cardiovascular disease, and/or type 2 diabetes. Such dementia has even been called “type 3 diabetes,” referring to preferential, adverse effects of insulin resistance on the brain. Both heart disease and type 2 diabetes are overwhelmingly preventable with lifestyle. This is established by a vast aggregation of diverse research; is reflected in the health status of the world's Blue Zone populations; and is further validated by the results of intervention at the level of a whole population over a span of decades.

The new study leaves us, as research so often does, with more questions than answers. But we may gratefully imbibe the dose of good news, even as we work to know just where it came from, and how we might go from a cup half full, to one full to the brim.

For now, though, we do know that risk factors for dementia are much the same as those for type 2 diabetes and heart disease, which in turn we know how to prevent with lifestyle. We could do a world of good for bodies and minds alike by persuading hearts and minds around the world to put to full use at long last knowledge we have long had about the primacy of lifestyle.

David L. Katz, MD, FACP, MPH, FACPM, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. He is the Director and founder (1998) of Yale University's Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, Conn.; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. This post originally appeared on his blog at The Huffington Post.

Labels: , , , , ,


Post a Comment

Subscribe to Post Comments [Atom]

<< Home

This is a printer-friendly version of this page

Print this page  |  Close the preview




Contact ACP Internist

Send comments to ACP Internist staff at

Blog log

Members of the American College of Physicians contribute posts from their own sites to ACP Internistand ACP Hospitalist. Contributors include:

Albert Fuchs, MD
Albert Fuchs, MD, FACP, graduated from the University of California, Los Angeles School of Medicine, where he also did his internal medicine training. Certified by the American Board of Internal Medicine, Dr. Fuchs spent three years as a full-time faculty member at UCLA School of Medicine before opening his private practice in Beverly Hills in 2000.

And Thus, It Begins
Amanda Xi, ACP Medical Student Member, is a first-year medical student at the OUWB School of Medicine, charter class of 2015, in Rochester, Mich., from which she which chronicles her journey through medical training from day 1 of medical school.

Ira S. Nash, MD, FACP, is the senior vice president and executive director of the North Shore-LIJ Medical Group, and a professor of Cardiology and Population Health at Hofstra North Shore-LIJ School of Medicine. He is Board Certified in Internal Medicine and Cardiovascular Diseases and was in the private practice of cardiology before joining the full-time faculty of Massachusetts General Hospital.

Zackary Berger
Zackary Berger, MD, ACP Member, is a primary care doctor and general internist in the Division of General Internal Medicine at Johns Hopkins. His research interests include doctor-patient communication, bioethics, and systematic reviews.

Controversies in Hospital Infection Prevention
Run by three ACP Fellows, this blog ponders vexing issues in infection prevention and control, inside and outside the hospital. Daniel J Diekema, MD, FACP, practices infectious diseases, clinical microbiology, and hospital epidemiology in Iowa City, Iowa, splitting time between seeing patients with infectious diseases, diagnosing infections in the microbiology laboratory, and trying to prevent infections in the hospital. Michael B. Edmond, MD, FACP, is a hospital epidemiologist in Iowa City, IA, with a focus on understanding why infections occur in the hospital and ways to prevent these infections, and sees patients in the inpatient and outpatient settings. Eli N. Perencevich, MD, ACP Member, is an infectious disease physician and epidemiologist in Iowa City, Iowa, who studies methods to halt the spread of resistant bacteria in our hospitals (including novel ways to get everyone to wash their hands).

db's Medical Rants
Robert M. Centor, MD, FACP, contributes short essays contemplating medicine and the health care system.

Suneel Dhand, MD, ACP Member
Suneel Dhand, MD, ACP Member, is a practicing physician in Massachusetts. He has published numerous articles in clinical medicine, covering a wide range of specialty areas including; pulmonology, cardiology, endocrinology, hematology, and infectious disease. He has also authored chapters in the prestigious "5-Minute Clinical Consult" medical textbook. His other clinical interests include quality improvement, hospital safety, hospital utilization, and the use of technology in health care.

Juliet K. Mavromatis, MD, FACP, provides a conversation about health topics for patients and health professionals.

Dr. Mintz' Blog
Matthew Mintz, MD, FACP, has practiced internal medicine for more than a decade and is an Associate Professor of Medicine at an academic medical center on the East Coast. His time is split between teaching medical students and residents, and caring for patients.

Everything Health
Toni Brayer, MD, FACP, blogs about the rapid changes in science, medicine, health and healing in the 21st century.

Vineet Arora, MD, FACP, is Associate Program Director for the Internal Medicine Residency and Assistant Dean of Scholarship & Discovery at the Pritzker School of Medicine for the University of Chicago. Her education and research focus is on resident duty hours, patient handoffs, medical professionalism, and quality of hospital care. She is also an academic hospitalist.

Glass Hospital
John H. Schumann, MD, FACP, provides transparency on the workings of medical practice and the complexities of hospital care, illuminates the emotional and cognitive aspects of caregiving and decision-making from the perspective of an active primary care physician, and offers behind-the-scenes portraits of hospital sanctums and the people who inhabit them.

Gut Check
Ryan Madanick, MD, ACP Member, is a gastroenterologist at the University of North Carolina School of Medicine, and the Program Director for the GI & Hepatology Fellowship Program. He specializes in diseases of the esophagus, with a strong interest in the diagnosis and treatment of patients who have difficult-to-manage esophageal problems such as refractory GERD, heartburn, and chest pain.

I'm dok
Mike Aref, MD, PhD, FACP, is an academic hospitalist with an interest in basic and clinical science and education, with interests in noninvasive monitoring and diagnostic testing using novel bedside imaging modalities, diagnostic reasoning, medical informatics, new medical education modalities, pre-code/code management, palliative care, patient-physician communication, quality improvement, and quantitative biomedical imaging.

Informatics Professor
William Hersh, MD, FACP, Professor and Chair, Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, posts his thoughts on various topics related to biomedical and health informatics.

David Katz, MD
David L. Katz, MD, MPH, FACP, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care.

Just Oncology
Richard Just, MD, ACP Member, has 36 years in clinical practice of hematology and medical oncology. His blog is a joint publication with Gregg Masters, MPH.

Kevin Pho, MD, ACP Member, offers one of the Web's definitive sites for influential health commentary.

MD Whistleblower
Michael Kirsch, MD, FACP, addresses the joys and challenges of medical practice, including controversies in the doctor-patient relationship, medical ethics and measuring medical quality. When he's not writing, he's performing colonoscopies.

Medical Lessons
Elaine Schattner, MD, FACP, shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology, and as a patient who's had breast cancer.

Mired in MedEd
Alexander M. Djuricich, MD, FACP, is the Associate Dean for Continuing Medical Education (CME), and a Program Director in Medicine-Pediatrics at the Indiana University School of Medicine in Indianapolis, where he blogs about medical education.

More Musings
Rob Lamberts, MD, ACP Member, a med-peds and general practice internist, returns with "volume 2" of his personal musings about medicine, life, armadillos and Sasquatch at More Musings (of a Distractible Kind).

David M. Sack, MD, FACP, practices general gastroenterology at a small community hospital in Connecticut. His blog is a series of musings on medicine, medical care, the health care system and medical ethics, in no particular order.

Reflections of a Grady Doctor
Kimberly Manning, MD, FACP, reflects on the personal side of being a doctor in a community hospital in Atlanta.

The Blog of Paul Sufka
Paul Sufka, MD, ACP Member, is a board certified rheumatologist in St. Paul, Minn. He was a chief resident in internal medicine with the University of Minnesota and then completed his fellowship training in rheumatology in June 2011 at the University of Minnesota Department of Rheumatology. His interests include the use of technology in medicine.

Technology in (Medical) Education
Neil Mehta, MBBS, MS, FACP, is interested in use of technology in education, social media and networking, practice management and evidence-based medicine tools, personal information and knowledge management.

Peter A. Lipson, MD
Peter A. Lipson, MD, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. The blog, which has been around in various forms since 2007, offers musings on the intersection of science, medicine, and culture.

Why is American Health Care So Expensive?
Janice Boughton, MD, FACP, practiced internal medicine for 20 years before adopting a career in hospital and primary care medicine as a locum tenens physician. She lives in Idaho when not traveling.

World's Best Site
Daniel Ginsberg, MD, FACP, is an internal medicine physician who has avidly applied computers to medicine since 1986, when he first wrote medically oriented computer programs. He is in practice in Tacoma, Washington.

Other blogs of note:

American Journal of Medicine
Also known as the Green Journal, the American Journal of Medicine publishes original clinical articles of interest to physicians in internal medicine and its subspecialities, both in academia and community-based practice.

Clinical Correlations
A collaborative medical blog started by Neil Shapiro, MD, ACP Member, associate program director at New York University Medical Center's internal medicine residency program. Faculty, residents and students contribute case studies, mystery quizzes, news, commentary and more.

Interact MD
Michael Benjamin, MD, ACP member, doesn't accept industry money so he can create an independent, clinician-reviewed space on the Internet for physicians to report and comment on the medical news of the day.

PLoS Blog
The Public Library of Science's open access materials include a blog.

White Coat Rants
One of the most popular anonymous blogs written by an emergency room physician.

Powered by Blogger

RSS feed