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Monday, July 27, 2015

Nutrients, nutritionism, and historical nuttiness

The current issue of JAMA features a commentary by two colleagues, calling for an end to what they term the “ban” on total dietary fat. More specifically, the authors are endorsing the report of the 2015 Dietary Guidelines Advisory Committee, of which I too am a fan, in which there is no specific reference to an upper limit for total dietary fat intake.

There are a number of important implications in this.

First, the case for abandoning an emphasis on limiting total dietary fat intake is clearly legitimate and overdue. The world's healthiest populations vary widely in their total dietary fat intake, but vary far less in the basic theme of their diets. In all cases, they consume diets of wholesome foods in sensible combinations; real foods, not too much mostly plants- to borrow from Michael Pollan.

We have long had abundant evidence that reference to total dietary fat was a stark failure to differentiate baby and bathwater. Some classes of fat, notably manufactured trans fats, are consistently and uncontestably harmful. Some classes of fat contain specific members that are harmful and others that may be innocuous; this is where the evidence currently stands for saturated fat. The current enthusiasm for attributing health benefits to saturated fats may be a product of wishful thinking, reactionary excess, or ulterior motives, but is not a product of the current weight of scientific evidence. Of note, the Dietary Guidelines Advisory Committee report, and the new commentary in JAMA, both preserve the recommendation to limit total saturated fat intake.

Some fats may be beneficial or harmful, depending on total dose and proportion to their counterparts; this is our current understanding of omega-6 polyunsaturates. Like omega-3 fats, omega-6 fats are essential nutrients; but we are prone in modern diets to a relative deficiency of the former, and a relative excess of the latter. Because our intake of omega-3 polyunsaturates tends to be relatively low and these fats are essential nutrients, more would be better in most cases. Monounsaturated fats, indelibly associated with the Mediterranean diet, are generally thought to be health promoting.

Second, as noted in the JAMA piece, we have other nutrients of concern these days. Our fixation on fat for many years resulted in marked increases in our intake of refined grains and added sugars. These are both major liabilities of the modern diet, and an obsolete emphasis on limiting total fat intake may lead inadvertently to ills in this other direction.

Third, there has long been a disconnect between the lingering reference to total fat and recommendations for specific foods. Fish, especially fatty fish, are consistently associated with health benefits, and are recommended in the Dietary Guidelines for Americans. The health benefits of the very-high-fat avocado are widely recognized. And, in particular, nuts and seeds are consistently and decisively associated with health benefits, and recommended rather prominently in both the 2010 Dietary Guidelines for Americans, and the 2015 advisory committee report. It does not make a lot of sense to advise limiting intake of nutrients while advising increased consumption of foods in which those nutrients are found.

Fourth, and finally, there is the precautionary tale of our recent nutritional history, which has been, in a word, nutty. For literal decades now, we have fixated on some particular nutrient while looking right past foods, and overlooking the overall dietary pattern. We have managed to invent an unending variety of junk foods, each under the halo of some particular nutrient “virtue:” low fat; low carb; low fructose; vitamin fortified; gluten free. We have invented a parade of ways to eat badly, and are, predictably, mostly fatter and sicker as a result.

So while the plea in JAMA to lift the “ban” on total dietary fat is valid, the silence on the topic in the DGAC report may be even more so. The DGAC decided to de-emphasize nutrients altogether, and instead to emphasize the very items we have been overlooking, foods and dietary patterns. Their 572-page report is perhaps best encapsulated by this passage from the executive summary: “The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meats; and low in sugar-sweetened foods and drinks and refined grains. Additional strong evidence shows that it is not necessary to eliminate food groups or conform to a single dietary pattern to achieve healthy dietary patterns. Rather, individuals can combine foods in a variety of flexible ways to achieve healthy dietary patterns, and these strategies should be tailored to meet the individual's health needs, dietary preferences and cultural traditions. Current research also strongly demonstrates that regular physical activity promotes health and reduces chronic disease risk.”

While a cap on total dietary fat intake has proven to be unhelpful, it's worth noting that the wide range of variations on the theme of eating for optimal health all fall within a predictably judicious range. While some of the world's “best diet” contenders are very low in fat, and some as high as 40% of calories or more, none is extremely high. In all cases, though, this balance is achieved by an emphasis on foods. Diets proven in both research and real-world settings to be good for life-long health all emphasize vegetables, fruits, beans, lentils, and whole grains, all of which are natively low in fat. When these are prominent, or predominant, in a diet, there is a limit to how high in total fat that diet can be.

History is the best judge of our actions and inclinations. The judgment of our proclivity for mono-nutrient fixations has been rendered, and it is quite harsh; we have been harming ourselves with its unintended consequences for decades. In contrast, the 8 years of history since Michael Pollan wrote about “nutritionism” in the New York Times have judged his insight to be of profound importance. Get the foods right, and nutrients will take care of themselves; focus on any given nutrient, and there is good chance of inventing yet another way of eating badly.

When we know that some dietary fats are rather sinister, and others quite salutary, failure to unbundle the two is obsolete nonsense. When we know we are prone to remove healthful fats from our diets and replace them with sugar, an emphasis on total fat intake in dietary guidance is obsolete nonsense. A clear verdict has been rendered in the case of nutritionism, and it is guilty of crimes against humanity.

But let's be careful. The right response is not to canonize the nutrients we once vilified, but to de-emphasize nutrients and emphasize wholesome foods. Recommending for the intake of nuts, but against the fat content of nuts, was always just plain nutty. Failure to learn from the follies of our nutritional history would be even more so.

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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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.

Auscultation
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.

DrDialogue
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.

FutureDocs
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.

KevinMD
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).

Prescriptions
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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