ACP Internist Blog


Monday, May 22, 2017

Heart disease is not hypothetical

A new commentary just published in the British Journal of Sports Medicine contends that saturated fat is uninvolved in coronary artery disease. Before you get too excited: the commentary is comprised only of theory and opinion, none of it new, all of it expressed by these same authors before. The cited support involves no new research either.

I confess I don't understand why hypothesizing by several cardiologists who have expressed this opinion before, involving no new research, citing review articles from two and three years ago on the causes of coronary artery disease should be worthy of publication in the peer-reviewed literature. Generally, it requires more than mere speculation, let alone repeating prior speculation, to clear that bar. I further don't understand why, in light of all the new research coming out weekly, a commentary lacking both novel comments and new research should be newsworthy. But the media picked this one up just the same.

But perhaps we can account for it after all. The authors make a theoretical argument to contend that saturated fat is not a cause of heart disease. There is nothing we seem to like better in the nutrition space than hearing that everything we thought we knew was wrong, and renewing our license to procrastinate and eat whatever we want. This particular scientific journal's parent has earned a dubious reputation for favoring dietary dissent over consensus, for whatever reasons. As for the media, there is nothing they tend to like better than an endless sequence of comforting the afflicted and afflicting the comfortable, because perpetual confusion means you will need to tune in tomorrow for the newest “truth” populating the most recent 20-minute news cycle.

There's just one problem with all of this theorizing: there is nothing theoretical about coronary disease. Heart disease remains the leading cause of premature death among men and women alike in the U.S., and increasing portions of the world. Heart disease is not hypothetical. It is an almost entirely unnecessary epidemiological scourge siphoning years from lives and life from years.

The new commentary is, in a word, wrong. It is not necessarily wrong in every particular about saturated fat. There are some legitimate uncertainties there. It is wrong in the whole, because it commits the willful deception, or classic blunder, of conflating the part for the whole.

Whatever the specific, mechanistic involvement of any given saturated fatty acid with atherogenesis and coronary disease, the reliably established fact is that diets high in the foods that are high in saturated fat lead to high rates of heart disease- while many variations on the theme of diets low in saturated fats, whether low high or middling in total fat, are associated with lower rates of heart disease, lower rates of all chronic disease, and lower rates of premature death.

The choice of citations in this commentary is highly selective, very limited, and the interpretation of the studies is flagrantly biased. These authors didn't happen upon this opinion because they just reviewed the literature and found a surprise. They are well established, even famous, for espousing exactly this opinion, so they knew the answer before ever they posed a question. Science tends to be better when the question precedes the answer.

Their conclusion that saturated fat is exonerated is based on straw-man arguments. For one thing, it is very hard to isolate the effects of saturated fat. This is because saturated fat is a diverse class of nutrients with differing effects; because saturated fat is consumed in foods, not by itself; and because more of THESE foods in one's diet ineluctably means less of THOSE foods. Consequently, the attribution of health effects to just one dietary factor is very difficult. The more enlightened researchers in this space have long shifted their focus to overall dietary patterns, and there, the evidence is nothing short of overwhelming: dietary patterns that produce the best health outcomes overall, including less cardiovascular disease, may be high or low in total fat, but are invariably plant-predominant and low in saturated fat.

The best evidence regarding the best diets all points to wholesome foods, predominantly plants, in sensible combinations, but provides no decisive evidence that any one level of total fat is best. What matters are the sources of that fat, with nuts, seeds, olives, extra virgin olive oil, avocado, fish, and seafood favored.

High-fat Mediterranean diets have shown great results, but so have vegan and vegetarian diets, and very low-fat omnivorous diets like that of the Tsimane, so recently in the news. The Tsimane reportedly derive up to 72% of their calories from carbohydrates; have very low dietary fat intake; experience inflammation on which the current authors blame coronary disease, but due to infections not eating sugar; and yet have the cleanest coronaries ever studied. Fat level, per se, simply does not appear to be a relevant consideration. But the kind of fat, and the sources of that fat, clearly are. Why would these authors conflate the two?

Why, in particular, would they fail even to mention the Tsimane if their commentary were aiming at illumination on this topic? The answer is they would not. They failed to mention them, or any studies at odds with their predetermined conclusion, because their goal appears to be self-promotion born of controversy. Controversy sells.

To be fair, there are some valid points in the commentary, but they are so lost in a haze of obfuscation that they are devoid of all value.

Imagine a commentary arguing that, in theory, one particular compound or group of compounds in cigarettes is not responsible for emphysema, or lung cancer. We might already be convinced that these compounds are involved, based on the weight of evidence. We might have meaningful, residual doubts about the specific role of these compounds relative to other constituents of tobacco. But we know for sure that cigarettes, per se, are overwhelmingly linked to both emphysema and lung cancer.

But not so fast! our commenting theorists tell us. They remind us of the want of randomized controlled trials. They focus their discussion on this one compound, and point out the uncertainties and methodologic challenges in linking this particular moiety to lung cancer. They espouse theories about general mechanisms, random mutations, and the inflammatory effects of psychological stress. They cite very impressive sounding work, such as papers in Science telling us that random mutations occur routinely. They systematically avoid citing any impressive research addressing less comfortable areas, such as the paper in Nature indicating that the majority of all cancer is preventable by modifying lifestyle, with avoidance of tobacco at the top of the list. And, they avoid any mention of staggering volumes of evidence establishing the association not between one chemical, but tobacco itself-with emphysema, lung cancer, and other highly undesirable fates.

Such an argument would be almost exactly analogous to the one now making news. The commentary is mostly wrong, but even when it isn't wrong, it is profoundly misleading, unless you think uncertainties about which chemical in cigarettes is guilty of tobacco's crimes against humanity, as a license to go back to smoking until the experts sort it all out.

In a paragraph in the middle of the new commentary, the authors all but declare their profound bias, and commitment to finding and citing only evidence in line with the opinion they owned at the start. They contrast a “low fat” diet deriving 37% of calories from fat, with a healthy Mediterranean diet deriving 41% of calories from fat, and use the favorable outcomes in the Mediterranean diet arm to dismiss and disparage “low fat” diets, and by insinuated extension, diets generously comprised of mostly vegetables, fruits, whole grains, beans, and lentils.

What isn't preposterous about this reasoning is just plain mendacious. First, 37% of calories from fat is higher than the typical American diet; calling it low-fat is truly bewildering. This is like contrasting 37 cigarettes a day to 41 cigarettes a day. If you think lack of decisive benefit from those four fewer daily cigarettes means it makes no difference whether or how much you smoke, this commentary is for you!

Second, the paper was, as declared in its own title, about saturated fat- what does low total fat (whether described fairly or unfairly) have to do with it? Nutrition experts around the world all but uniformly emphasize the variety and balance of fats over the total quantity, a position formalized in the 2015 Dietary Guidelines Advisory Committee Report in the U.S. Personally, I have long concluded that total fat content is a very poor indicator of diet quality, just as total carbohydrate is. Avocado and wild salmon are high in fat, and so is pepperoni pizza. Lollipops are high in carbohydrate, and so are lentils. A focus on macronutrients is yesterday's news, was yesterday's news yesterday, and in the context of the new commentary, is a diversionary tactic.

Speaking of fats and carbohydrates, these authors go on to borrow a page from the playbook of every “It's all about the carbs” iconoclast preceding them, suggesting that coronary disease is due to inflammation, and that, in turn, is due to refined carbohydrate and added sugar. The problem here is the obvious one: there is no need to choose. Those of us who know that beans are much better for you than bacon-cheeseburgers also know that water is much better for you than Kool-Aid, and steel-cut oats far better than Pop-Tarts. The idea that you need to pick a dietary scapegoat is one of the great boondoggles of modern public health, and only serves the interests of the junk food industry, ever ready to put lipstick on a new pig.

As for the authors' references to the Mediterranean diet, I can only say I share their enthusiasm. But what the PREDIMED diet showed, and the Lyon Diet Heart Study before it-is the superiority of a diet high in unsaturated fat from olives and avocados, nuts and seeds, and to a lesser extent fish and seafood- to a diet high in sources of saturated fat. THERE WAS NO ‘LOW FAT’ DIET IN THE COMPARISON. That contention is either willfully misleading or an indication of plain ignorance.

I do have one hypothetical provocation of my own. Let's imagine that a diet rich in beans, and a diet rich in beef, were comparably good for our coronaries. The evidence indicates that is untrue, but let's pretend. If we really had such options for health, we would still have no real option for the environment. The environmental argument for plant-predominant diets is, if anything, stronger than the health arguments. For academics in the public health space to offer dietary advice in the age of climate change and ignore the planetary impactof choices made by 8 billion hungry Homo sapiens is a sad abdication of an obvious responsibility we all share.

There is nothing hypothetical about coronary artery disease; it is a real, clear, and omnipresent danger. Its association with dietary patterns and key dietary components is reliably established by staggering volumes of evidence these commentators simply chose to ignore. If you are inclined to buy this misguided and misleading theorizing about diet, keep your credit card handy; I am confident that tobacco industry theorists have something to sell you, too.

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.

A personality trait that may help us minimize diagnostic errors

I found this article fascinating, “The Surprising Personality Trait That Massively Improves Decision-Making, According to Science.” The trait is called intellectual humility!

From the paper: “In everyday language, it means the willingness to accept that you might be wrong and to not get defensive when arguments or information that's unfavorable to your position comes to light.”

In medicine, we often have to assume a diagnosis when a patient enters the hospital. We often assume a diagnosis in outpatient settings. In both cases, we then should look for confirmatory evidence to either support our assumption or counter our assumption. The supporting data help us solidify our diagnosis, but too often we minimize evidence against our initial assumption. There are many heuristics possibility at work here – the mostly commonly cited are premature closure or the anchoring heuristic.

Intellectual humility protects us against these heuristics: “This is not to say that no one has trumpeted the importance of intellectual humility. On the HBR blogs, career coach Mark Bonche recently wrote about how fast learning requires a willingness to admit error, and various business gurus and VCs have long argued that the best kind of thinker is one with ‘strong opinions weakly held.’”

Final advice from the paper's author:

“Some leaders have long understood the importance of “intellectual humility” then, but it's clear from both the current political climate and plenty of business missteps that not everyone has internalized the value of incorporating a whole lot of humility into your decision making. For those folks, this study might serve as a healthy reminder that you can't learn if you can't admit that you might be wrong.”

Unfortunately, we physicians sometimes lack intellectual humility. Perhaps just understanding its importance will help us gain this important trait.

db is the nickname for Robert M. Centor, MD, FACP. db stands both for Dr. Bob and da boss. He is an academic general internist at the University of Alabama School of Medicine, and is the Regional Associate Dean for the Huntsville Regional Medical Campus of UASOM. He still makes inpatient rounds over 100 days each year. This post originally appeared at his blog, db's Medical Rants.
Friday, May 19, 2017

Overcoming drug addiction solo: A mother finds strength

Recently, I saw a young woman referred to me for an opinion on her hepatitis C infection.

In the latter part of 2013 she made an unwise decision and started using intravenous drugs. She also made a more unwise decision and shared needles. She is fortunate that the only virus she contracted was hepatitis C, now curable. I do not know the details of her life then which led her to lean over the edge of a cliff. It would seem to most spectators that her new lifestyle would portend an inexorable slide into an abyss. Young addicts, for example, often cannot fund their addictions, and resort to criminal activities to generate necessary revenue. Employment status and personal relationships become jeopardized. The tapestry of a person's life can rapidly unravel.

But, none of this happened. About two years after the first shared needle pierced her vein, she quit and she's been clean since. It was nearly a year later that she first saw me in the office accompanied by her young, spirited son. I asked her how she molted and emerged from a grim and dangerous world of self-destruction. “Who helped her?” I inquired. ”No one,” she said. She had thrown the devil off her back herself, and had dispatched him to a place so distant that he would never find her again.

Consider how extraordinary this life-preserving act was. Only someone who has overcome a true addiction can understand the magnitude of this act. That she succeeded alone only magnifies the accomplishment. I admired her grit and devotion, but I couldn't feel it on a visceral level since I have never suffered from an addiction.

She told me that she her two young kids gave her the motivation she needed to put her needles aside. She owes them a great debt. They gave her a gift that she can never repay. But, I have a sense that she will spend the rest of her life giving back to them.

This post by Michael Kirsch, MD, FACP, appeared at MD Whistleblower. Dr. Kirsch is a full time practicing physician and writer who 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.

Mycobacterium chimaera: How big is the iceberg? And about that iceberg ...

The reports of invasive Mycobacterium chimaera infections linked to heater-cooler devices keep rolling in, but still nobody has any idea how big this problem is. Mike and I each get sporadic e-mails or calls from places where new cases have popped up, and I'm convinced we are still dealing with the proverbial “tip of the iceberg.” The knowledge that invasive M. chimaera disease should be in the differential for certain symptoms after cardiac surgery is still spotty, and confined to those who practice ID or cardiothoracic surgery. Most patients who develop vague symptoms like weight loss and fatigue (even those who got a valve replaced a year ago) are likely to go to their primary care physician first. Only those affected who encounter someone familiar with this global outbreak are likely to get the right diagnostic evaluation (to include AFB cultures). Hence this pattern: a case is detected in a given location, after which there is a lot of attention focused on the problem, including media reports and provider notifications, and then several more cases are discovered.

My current unofficial (and extremely incomplete) global case count is at least 108, which includes cases reported in the news or in published reports from public health agencies, meetings, or journals. This count includes cases from US (New York, Ohio, Pennsylvania, Michigan, Minnesota, Iowa, Tennessee, Florida, and California), England, Ireland, Switzerland, Germany, Netherlands, France, Spain, Hong Kong, and Australia.

I'm sure there are many more we've not heard about, so feel free to email or comment below if you know of others. The bottom line is that we are long overdue for (1) mandatory public reporting of invasive non-tuberculous mycobacterial disease, and (2) a global registry to track this outbreak, and to help inform diagnosis, treatment and prevention approaches.

I'll bet the image of an iceberg is the most common single image used in presentations about infection prevention and antibiotic resistance (possibly several other fields, too). It's a great graphic for depicting the idea that a problem is much bigger than it may appear on superficial or initial assessment (for example, that clinical cultures miss the vast majority of carriers of resistant organisms, or that active TB cases are vastly outnumbered by latent TB cases). I think I've used an image of an iceberg in at least 2 dozen talks, maybe more. Anyway, as a profession I think we should move on to this iceberg photograph. I nominate this one by Joshua Holko, based upon the facts that (1) it is an actual photo (I hope!), (2) it still shows how large the portion of the iceberg below the water is, and (most importantly), (3) it has penguins!

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. This post originally appeared at the blog Controversies in Hospital Infection Prevention.