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

Friday, September 16, 2016

Diets, doubts, and doughnuts: are we truly clueless?

No, we are not, absolutely not, emphatically not clueless about the basic care and feeding of Homo sapiens. The fundamental lifestyle formula, including diet, conducive to the addition of years to our lives, and life to our years, is reliably clear and a product of science, sense, and global consensus. Really. You can be confused about it if you want to be, but I advise against it. You will be procrastinating, and missing out- because healthy people have more fun.

In the New York Times this past week, Gina Kolata made the case that almost all studies about diet, exercise, and health are suspect in 1 way or another, and that therefore we are confused about lifestyle practices for health, and justifiably so. The first point is valid; the second is utter nonsense. Let's take them in turn.

The contention that all research addressing lifestyle practices for health is limited in some way is certainly true, to the point of being both trivial and trite. All research is limited in some way; the perfect study has never been conceived, let alone executed. But we have nonetheless used research to produce very tangible results that prove the utility of our imperfect methods. We have put footprints on the moon; eradicated smallpox; put a spaceship in orbit around Jupiter; and routinely shoot perfectly clear messages to one another by jiggling electrons in cyberspace. Anyone exploiting the tools of modern living is a living illustration that research, though ineluctably flawed, works pretty darn well.

There is, moreover, a case to make that research addressing lifestyle practices may be especially prone to important limitations. If we consider that the pinnacle of evidence in human research is, generally, the randomized, double-blind, placebo-controlled trial, the challenges are immediately clear. How do you pair exercise, or an optimal diet, with some “placebo control,” while keeping your study participants blind to their treatment assignment? How can we have some people exercise, and others not, without them picking up on it? We cannot.

But that's just the start of our tribulations with such trials. Consider an effort to determine if, say, an optimal Mediterranean diet is better or worse for human health than an optimal vegan diet, or an optimal Paleo diet. The ultimate outcome of interest, healthy survival, is a product of both longevity and vitality. To address longevity, we need very long trials. Years won't do; we are talking decades.

Now, we must allow for the fact that lifestyle influences health throughout the lifespan. If we want to know what diet is best for health, we should therefore look across the entire lifespan. That means starting young. In fact, even young isn't early enough, because dietary effects begin in utero. There is even a case for them beginning with our grandparents, but we will let that epigenetic influence go for the sake of pragmatism.

Still, to study the lifelong effects of diet on health, we would need to randomize a very large cohort of pregnant women to different dietary patterns. The women would need to be alike in all ways but diet. They would need to adhere to their dietary assignment throughout pregnancy, then proceed to breast feeding, and adhere then as well. After that, as the large crop of infants is weaned from breast milk, those neonates would become the study participants, and it would be their turn to adhere to the dietary assignment- forever. After some span of decades, and the expenditure of a staggering sum, we would be able to look at differences in health outcomes, and perhaps attribute them to our intervention if too many other things were not now different between our groups.

I trust you understand why such a trial has not been conducted, and why you shouldn't hold your breath waiting for it. That leaves us with the lesser standards of research against which Ms. Kolata has chosen to inveigh.

But that does not leave us clueless, any more than the lack of a randomized comparison of treatment versus benign neglect is required to know that bullet holes through peoples' chests warrant emergency surgery. We have no randomized trials telling us that water puts out most fires, and yet our firefighters carry on as if they know what they are doing. We had no perfectly unassailable proof that we could put a spaceship into orbit around Jupiter, until we went ahead and based on imperfect science, did exactly that.

What we have done in all areas where science has proven its inimitable utility is look at the weight of evidence, and apply sense. That formula is vastly more powerful, useful, and nearly perfect than any one study has ever been.

In the case of lifestyle for health, the formula works perfectly well despite the research imperfections that trouble Ms. Kolata. She is quite right to recommend a raised eyebrow about any 1 study, and in particular, the hyperbolic headlines it is likely to engender. But look instead at the weight of evidence, encompassing randomized trials, mechanistic studies, observational epidemiology, and real-world experience at the level of whole populations- and you generate a rather emphatic mandate to keep that restless eyebrow at its low-altitude ease.

Consider the implications for yourself, and for that matter Ms. Kolata, if the lack of “perfect” research really made us clueless about diet. We would have no idea whether lentils or lollipops were a better source of sustenance. We could not judge the differential merits of dates, and jelly doughnuts. We would not know whether oatmeal and walnuts, or Doritos and Coca Cola made a better breakfast.

I very much doubt that Ms. Kolata has any difficulty judging the relative merits of kale and cheese doodles. But once we are in for that penny, we are in for a pound. If we know, despite our research imperfections, that broccoli is generally a terrific choice, and baloney not so much, then we clearly have a basis to understand something in spite of it all. There is no reason for that understanding to end with baloney, and indeed it does not. We, and Ms. Kolata, all make confident choices every day, informed by science, guided by sense.

No single study, about diet or anything else, is perfect. If that gets you exercised, go ahead and exercise your derisive eyebrow as Ms. Kolata advises. But on the other hand, the massive weight of evidence in the aggregate tips clearly and decisively. A global consensus of expert judgment concurs. Sense, applied a bit too seldom to be called “common,” alas, aligns. Routine physical activity and a diet of mostly minimally processed vegetables, fruits, whole grains, beans, lentils, nuts, seeds and water when thirsty redounds consistently to the advantage of human health. It offers benefits to the planet as well.

I recommend that you leave your eyebrow just where it is, and lift instead your feet, and your fork, accordingly.

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.

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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.

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