Why We Are Slaves Of Food Obsession.

A 95 years old psychology article holds the key to solving the obesity epidemic. It's not about a long forgotten medicine or an ancient psycho-trick. It's a simple observation about the dynamics of feeding. Vindicated by neurohormonal research, here is what it means to your struggle with extra pounds. [tweet this].

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The Truth About The Genetics Of Obesity.

Evolutionary selection favored those who became fat easily. That's the essence of the "thrifty gene hypothesis". It's like Madonna. On the wrong side of 50, and ripe to be dethroned by something with greater sex appeal. In this case the contender's name is the "drifty gene hypothesis". Here is why you shouldn't be too dazzled about it. [tweet this].    

Exactly 50 years ago, Neel suggested that the high rate of diabetes in our society is the result of  evolutionary selection which favored those of our ancestors whose genes made them store fat more efficiently during periods of food abundance [1]. It's such a marvelously simple explanation that it doesn't take the brains of an Einstein to chatter about it at any dinner party where one wants to be remembered as quite the hobby geneticist. But to every party there is a party pooper. In this case two of them. John R. Speakman and Klaas R. Westerterp are telling us that the high prevalence rate of obesity and diabetes actually disproves the thrifty gene hypothesis [2].

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What Infants Teach Us About Preventing Obesity.

Public health has been telling you for years: you are fat because you move too little and eat too much. And yes, it's your fault if you don't break a sweat every day to keep your waist line in check. But research says, that's not the entire truth. In fact, public health might have taken the easy way out, and here is how it could finally make amends. [tweet this].

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Why Medicine Might Be Wrong About Salt, Fat & BMI

Salt and fat kill you early, and your BMI tells you how early. That has been the wisdom for years, but wisdoms have an expiry date, too. Particularly medical wisdoms. Recent research says those three are probably well beyond their use-by date. [tweet this].  

We live in interesting times. Admitted, my view of times is myopic, it's focused on the biomedical. So, I'm obviously not referring to Greece teetering on the economic brink. In biomedicine our Greeks are the cherished wisdoms about salt, fat and BMI. Similarity 1: They are not doing so well. Similarity 2: Their balance sheet screams bankruptcy. Similarity 3: Our authorities won't kick them out for fear of a domino effect.

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How The Media Monkeys Get You Panicked About Sitting Too Long!

From "man is made to move" to "man is not made to sit" is a very recent transition of scientific insight. Let's get our readers panicked over more than not doing exercise, is the response of the media. Here is why you should sit down and get the facts straight before jumping up in fear. [tweet this].  

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Supplements: Nutrition Science Or Nutrition Crap?

Nutritionists claim they are doing science, consumers buy it, and the supplements industry makes a healthy living from it. Only you probably won't. Here is why: 

[tweet this].

One of the enduring diet questions is whether supplements are a good tool to (a) improve health, and (b) compensate for nutritional deficits of an enjoyable but less than healthy dietary habit.  
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Will The Polypill Prevent Your Heart Attack?

Giving the polypill to everybody above the age of 55 kills two birds with one stone: cardiovascular risk and preventive medicine. That's what the proponents of the polypill say. The medical establishment is in uproar. Here is why you should be, too. But for a different reason. [tweet this].

   

We are typically sold on the notion, that heart disease and stroke have become today's major killer, for one simple reason: We live far longer than our ancestors of a hundred years ago, whose major cause of death were infectious diseases. Their eradication has brought upon us the blessings of longer lives, and with it the detriments of aging related cardiovascular disease. It's root cause is elevated cholesterol, a theory enshrined in the so-called lipid hypothesis. Questioning it is to the medical establishment what Galileo's theories were to the catholic church: plain heresy. After all, cholesterol lowering drugs, the statins, are a blessing to mankind and substantial reducer of cardiovascular death. 

    

This is what nearly everyone believes.

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Why Risk Screening For Heart Disease Is As Good As Crystal Ball Gazing

If weather forecasts were as reliable as cardiovascular risk prediction tools, meteorologists would miss two thirds of all hurricanes, expect rain for 8 out of 10 sunny days, and fail to see the parallels to fortune telling.    

When you are older than 35 and visit your doctor, there is a good chance he will evaluate your risk of suffering a heart attack or stroke over the next 10 years. The motivation behind this risk scoring is to prevent such an event while you still can. After all, these cardiovascular diseases are the number one causes of disability and death. In Europe alone 1.8 Million people die from it every year. In fact, they die prematurely, which means at an age younger than 75. [tweet this].

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Are You A Unique Medical Case?

Research says yes, public health doesn't listen, and you suffer the consequences: too little benefits from generic interventions. And it could be so simple.

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10 Good Reasons Not To Exercise?

Exercise may actually be bad for you! A professor says he stumbled upon this "potentially explosive" insight. The New York Times has been quick to peddle it. And couch potatoes descend on it like vultures on road kill. But professors can get it wrong, too. 

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Why You Should Arm Your Bullshit Alarm Before Reading Diet News.

In the fight over best diet for health and weight loss, it's protein lovers vs. vegetarian zealots. So far, a clear winner has not emerged. Only one loser: you, the victim of biased research. Here is an example of why you should keep your bullshit alarm on high alert when reading about weight loss diets.  

[tweet this].

Ellen M. Evans and colleagues wanted to know whether overweight men and women differ in their body composition responses to different weight loss diets [1]. So they enrolled 58 men and 72 women with a BMI greater than 26, and randomized them into two diet groups.

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Can Chocolate Save You From Heart Attack?

The media says yes. Science says maybe. In the end, you decide. Here are the facts:


A truffle treatment for heart disease is imminent. That's what a recent article suggests, headlined in the New York Daily News as: "Dark chocolate cuts heart deaths; Study shows benefits for high risk cardiac patients." 

The funny thing is, the cited  study does not show what the media geniuses claim it does. So, let's look at this master piece of research journalism and ...

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Can A Genetic Test Say Why You Are Fat?

With the decoding of the human genome came the hope of getting a lever on the chronic diseases, which kill most of us today: heart disease, stroke, diabetes and many cancers. And since overweight and obesity are a common cause of those diseases, many obese people were, and still are, yearning for that exculpatory headline: "It's all in your genes!" Why and how this headline is unlikely to ever appear in any serious media, was a subject of my earlier post "It's not your genes, stupid!".

Now, a group of researchers have looked at the data of a 30-year investigation of health and behavior, ...

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No Time To Exercise? You Are Not Alone!

Lack of time is the most often cited excuse for not exercising. I deliberately chose the word "excuse" over its less judgmental alternative "obstacle". Simply because I cannot see an "obstacle" when I compare two simple metrics: the hours people spend watching TV and the minutes needed to maintain one's health with exercise. With high intensity interval training, or HIT, health enhancing exercise can be compressed into an amazingly short amount of time. When done right. [tweet this].

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How to Live Longer And Exercise Shorter?

Let's face it, if exercise was really that much fun, everybody would do it and we wouldn't be fat, diabetic or die of heart disease. So when your doctor tells you that you better start exercising, your immediate question might be: how much do I have to do? The answer is, it depends. It depends on whether you want to hear the polite version or the truth.  [tweet this].

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3 Ways to Spot Their Lies About Healthy Recipes

Briefly: If I had to name the one word, that is most often used to label something as what it is not, my vote would go to "healthy". Whether it's the issue of sugar vs. honey, of butter vs. oil or of calories vs. nutrients, science and evidence are clearly not playing the lead role in the culinary theater of the world wide web. Judging by its popularity, that's a missed opportunity.

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The Death Of Good Cholesterol

Briefly

There were always two types of cholesterol, the good and the bad. Until now. A large new study tells us that good cholesterol might have been an impostor. That's food for the media types. For those who think before they type, the real news is that we are finally getting closer to uncovering the impostors. Thanks to the genetics revolution which seems to be paying off in an unexpected area.  

 

 

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Individualized Medicine, Ignorant Medics And An Invitation To Lose Weight.

In my previous post I promised to talk about your individualized way to achieving optimal health. If that made you think about personalized medicine, you were right. Almost. Because personalized medicine is still light-years away from us. That's the bad news. The good news, personalized prevention is an emerging reality. At least in my lab. Which is why I would like to invite you to become a part of it. No strings attached. But before we get to this let's first get on the same page about the personalization of medicine.

Two questions we need to ask ourselves: What is personalized medicine and why would we want it?

Professor Jeremy K Nicholson of the Imperial College, London, defined personalized medicine as "effective therapies that are tailored to the exact biology or biological state of an individual" [1]. Such tailoring of a treatment, say for your high blood pressure, would require your doctor to evaluate your biochemical and metabolic profile in order to prescribe you the most effective drug or treatment at the most effective dose, with the least possibility of side effects.

Now, why would we want this?

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How to survive the health care system.

You have heard about good and bad cholesterol. You have heard that increasing the former and reducing the latter will cut your risk of heart disease. You will now hear what's principally wrong with this strategy of attacking risk factors. And how it prevents us from eradicating the heart disease epidemic sweeping the globe. 

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Why your heart attack may just be collateral damage in big pharma's turf wars.

When a pharmaceutical company tells you that its drug is safer than it really is, it probably plays with your health. And possibly with your life. That's not a very nice thing to do. But it's also very profitable. Which is why it happens more often that you care to know. 

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The one way to make you slim, fit and healthy?

That your fattening lifestyle drives health insurance costs up is nothing but a fat lie. That much I have told you in the previous post. With Marlboro Man and Ronald McDonald doing better for your health insurer's balance sheet than Healthy Living, you might think that public health should look beyond economics as an argument for health.  In this post I will tell you why they shouldn't. 

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Who says being fat is bad?

Would you have guessed that, one fine day, health insurers will regret the demise of big tobacco and its contribution to health care costs? Would you have guessed that, when that day arrives, health insurers would also learn to love other frowned-upon-vices of their policy holders, such as getting fat and lazy? Your answer is probably "no, I wouldn't have guessed that in my dreams.". 

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Pass me the salt. And shut up about stroke risk.

They say, statistics lie.

That's a bad rep for a science, which has no other aspiration than that of making sense from data, of discovering an association between salt intake and stroke, of proving that the former causes the latter. Statistics is above lies. Those who interpret it are not. 

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Guess who is hiding the magic pill to longevity?

Imagine a medicine which protects you against cardiovascular disease, cancers, diabetes, depression and dementia. A medicine which works best when taken regularly and long before any symptoms of any of those diseases appear. A medicine which is cheaper than any supplement or aspirin. Would you take it?

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Your shortcut to longevity.

If you don't die from an accident, a serious infection or a cancer, you'll live as long as your arteries let you. And how long they let you is all in your hands. I know this sounds over-simplified, but it's biomedical knowledge in a nutshell. Lets look at what happens in and to your arteries and what that means for keeping them in mint condition. 

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It's not your genes, stupid.

Imagine traveling back in time and meeting your caveman ancestor of 10,000 years ago. Imagine telling him about what life is like today: that, with the tap of a finger you turn darkness into light, a cold room into a warm one and a tube in the wall of your cave into a spring of hot and cold water. You tell him...

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To hell with exercise

Who says that exercise is medicine? For one, the American College of Sports Medicine (ACSM) of which I'm a professional member. Then, how can I say it isn't?

Let's look first at the conventional view of the benefits of exercise. There is a large and increasing amount of evidence which clearly tells us that exercise prevents today's number 1 killer: cardiovascular disease. That is, heart attack, stroke and peripheral vascular disease. Mind you, what is common knowledge today emerged only some 50 years ago when Morris and colleagues discovered that UK bus conductors, the guys climbing up and down the double-decker London buses, had better fitness and fewer heart attacks than their all-day-seated driver colleagues [1].

In the years since then our knowledge about the effects of physical activity on cardiovascular, metabolic and mental health has virtually exploded. From this evidence the U.S. Dept. of Health and Human Services (HHS) concluded in 2008 that the most active people of the population have a 35% reduced risk of dying from cardiovascular disease compared to the least active people [2]. The WHO lists insufficient physical activity (PA) as the 4th leading cause of death world wide after high blood pressure, tobacco use and high blood glucose. What's wrong with this picture? High blood pressure and high blood glucose are known consequences of a sedentary lifestyle. So is obesity, which ranks 5th place on the WHO killer list. Which is why physical inactivity deserves top spot on that list.

What most people don't know is the way lack of physical activity causes all those diseases, from insulin resistance and diabetes to arterial dysfunction and atherosclerosis, and from there to heart attack, stroke, kidney failure. The mechanisms are extremely complex, and, while we have untangled quite some of them, there are probably a lot more to discover. I'll try to make this the subject of one of the next blog posts. 

Now you are probably asking yourself, how the hell, with all this evidence, will I ever be able to make my point that physical activity is not a medicine. Ok, here it comes: it's a matter of viewpoint. The one I'm taking is the one of evolutionary biology. Let me play its advocate and present as evidence a couple of insights.

First, our human ancestors, who had roamed this Earth as hunter/gatherers for the most part of human existence, had, by necessity, a much more physically active lifestyle. A lifestyle which required at least 1.7 to 2 times the normal resting energy expenditure [3]. [To get an idea about resting energy expenditure and physical activity levels and how they are calculated, simply follow the links to the videos.] Those ancestors' genes are what we have inherited. And these genes are exposed to a lifestyle which is vastly different from the ones under which these genes evolved. Specifically with a view to physical activity, which brings me to evidence no 2:

What we typically observe today are physical activity levels with factors of somewhere between 1.2 and 1.4 of our resting energy expenditure. That's true for most people.

Even if you were to follow the ACSM's recommendation of 30 minutes of moderate to vigorous exercise on at least 5 days per week, would you NOT reach the level of 1.7 if you are working in a typical office job or doing house work. Which means, the physical activity levels which we recommend today, do not add a behavioral type of medicine into our lives, they merely reduce the extent of a "poisonous" behavior called sedentism. It's like cutting down from 2 packs of cigarettes per day to 1 pack. Would you call this a "medicine"? Would the ACSM call that a medicine? With respect to exercise they do.

So, OK, if you had been attracted to this post in the hope of finding some excuse for not doing exercise, or some argument to get those exercise evangelists, like myself, off your back, I'm sorry to have disappointed you. No, actually, I'm not sorry. And neither will you be, if you get your physical activity level above those 1.7. Then you may just start calling exercise a medicine. Until then, chances are you will still go to hell with exercise, because you get too little of it. Certainly too little to stay out of that hell of heart disease, stroke, diabetes and many cancers.

1.           Morris, J.N. and P.A. Raffle, Coronary heart disease in transport workers; a progress report. Br J Ind Med, 1954. 11(4): p. 260-4.

2.           Physical Activity Guidelines Advisory Committee, Physical Activity Guidelines Advisory Committee Report, 2008, U.S. Department of Health and Human Services: Washington, D.C.

3.           Eaton, S.B. and S.B. Eaton, An evolutionary perspective on human physical activity: implications for health. Comp Biochem Physiol A Mol Integr Physiol, 2003. 136(1): p. 153-9.

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MORRIS JN, & RAFFLE PA (1954). Coronary heart disease in transport workers; a progress report. British journal of industrial medicine, 11 (4), 260-4 PMID: 13208943
Eaton, S., & Eaton, S. (2003). An evolutionary perspective on human physical activity: implications for health Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology, 136 (1), 153-159 DOI: 10.1016/S1095-6433(03)00208-3 PrintPDF

Screw Your Health?!

So, what's your excuse for not exercising enough, for smoking, for not watching your diet, for getting fatter every year, and therefore having high blood pressure, and too much glucose and cholesterol in your blood?

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Chronisch gesund geht doch!

In meinem vorangegangenen Beitrag habe ich erläutert, wie unser Gesundheitswesen dem Ziel der chronischen Gesundheit im Wege steht. Wie dieses Ziel erreichbar ist, ist Gegenstand meines heutigen Beitrags.

Gesundheit als shareholder value.

Anfang diesen Jahres drohte die Ratingagentur Standard & Poor's den G20 Nationen mit einer Herabstufung ihrer Ratings beginnend in 2015. Der Grund: Die bestehenden Gesundheits- und Rentensysteme werden unter der Krankheitskostenlast einer zunehmend älter, kränker und dementer werdenden Bevölkerung zusammenbrechen. Und damit das Wirtschaftswachstum ausbremsen.

Warum ist dieser Schuss vor den Bug so wichtig? Weil hier ausgesprochen wird, was schon lange hätte erkannt werden sollen: Gesundheit ist nicht nur das vielzitierte hohe Gut. Sie ist ein Wirtschaftsgut.

Ihre Gesundheit macht Sie produktiver für Ihren Arbeitgeber und profitabler für Ihre Krankenkasse und Ihren Lebensversicherer. Sobald Ihre Gesundheit im Universum des Shareholder Value auftaucht, haben Ihr Arbeitgeber, Ihre Kasse und Ihre Lebensversicherung auch finanzielle Anreize, in Ihre Gesundheit zu investieren. Und einen Anreiz, den Return-on-Investment mit Ihnen zu teilen. Im Rahmen einer Gesundheitsdividende, die Sie für Ihre Gesundheitsbemühungen belohnt. Das Schlüsselwort heißt Anreize. Fehlende Anreize sind der Grund für das Versagen der Präventionsbemühungen unseres Gesundheitswesens.

Egal ob Geld oder Anerkennung oder was auch immer Ihren Nachbarn grün vor Neid werden lässt, die treibende Kraft hinter allem menschlichen Handeln sind Anreize. Sie sind als Triebfeder unseres Handelns in unsere Hirne programmiert. In der programmiersprache des hyperbolic discounting. Wenn uns dieses Phänomen etwas gelehrt hat, dann ist es die Notwendigkeit von Anreizen, mit denen wir jene ausstechen können, die uns zu ungesundem Verhalten verführen.

Was hält unsere Firmen davon zurück, die Gesundheit ihrer Beschäftigten  massiv mit Anreizen zu fördern? Sicherlich nicht die Geringschätzung ihrer Beschäftigten. Und selten die Unberechenbarkeit des Return on Prevention. Meistens liegt es am Fehlen eines Werkzeugs, das es ermöglicht, Belohnung an jene zu verteilen, die es verdienen, und jenen vorzuenthalten, die nichts für ihre Gesundheit tun. Mit Yoga- und Betriebsportgruppen gelingt das sicherlich nicht. Dass solch ein Werkzeug im Rahmen betrieblicher Gesundheitsförderung funktioniert stellen wir gerade unter Beweis. Wir haben dieses Werkzeug entwickelt um damit auch die zweite und dritte Strategie zu realisieren.

Den eigenen Kopf überlisten

Wenn's ums Esesn geht lässt sich der Affe in uns kaum von dem kontrollieren, was uns zum Menschen macht: Vernunft und freier Wille. Aber egal ob Mensch oder Affe, Mutter Natur hat uns die Gabe des impliziten Lernens gegeben. Mit ihr lernen wir komplexe Aufgaben zu meistern ohne erklären zu können, wie wir das schaffen. Denken Sie ans Schwimmen oder ans Radfahren. Dies sind Beispiele für einen 6. Sinn, mit dem wir unser Verhalten präzise so steuern, dass wir weder ertrinken noch vom Rad stürzen. Warum nicht auch unser Essverhalten?  Mit einem 6. Sinn für die tägliche Kalorienbilanz schaffen Sie zwar nicht die Lust auf das Tiramisu aus der Welt, aber er hilft Ihnen zu erkennen, welche Maßnahmen notwendig sind, um Ihre Kalorienbilanz heute auf dem Kurs zu halten, mit dem Sie planmäßig Ihr Gewichtsziel erreichen. Dass es funktioniert haben wir in unserem Labor getestet. Die Idee dazu kam uns im Rahmen einer klinischen Studie, in der wir testeten, wie wir jenen Menschen zur chronischen Gesundheit verhelfen können, die am stärksten gefährdet sind: Übergewichtigen und Adipösen. Unser Probanden, die diesen 6. Sinn entwickelten, nahmen ab und hallten ihr Gewicht noch heute.     

Nun stellen Sie sich wahrscheinlich die Frage: Selbst wenn mein Arbeitgeber mir die notwendigen Anreize gibt, wie kann ich sicher sein, dass mein geändertes Bewegungs- und Ernährungsverhalten mir auch tatsächlich die chronische Gesundheit beschert? Womit wir beim letzten Punkt angekommen sind:

Die Biomedizin weiß was wirkt

Die Biomedizin kennt keine wirksamere Intervention zur Verhütung von Herzinfarkt, Schlaganfall und Diabetes als zielgerichtete Bewegung und Ernährung. Mit dieser Strategie reduzierten die Probanden des Diabetes Prevention Program das Risiko, Diabetes zu entwickeln um rund 60%. Jene Probanden die statt einer Lebensstiländerung das Medikament Metformin einnahmen, schafften nur halb so viel, 30% Risikoreduzierung.

Dass Bewegung das Risiko an chronischen Krankheiten zu sterben um 40% reduzieren kann, ist aus großen Studien bekannt. Damit ist Bewegung in ausreichender Intensität, Dauer und Häufigkeit die wirksamste Strategie zur Verhütung dieser Erkrankungen.  Auch vieler Krebserkrankungen, darunter Darmkrebs, Prostatakrebs und Brustkrebs.  Unser Gesundheitssystem aber verschleudert das Potenzial dieser Strategie, denn es ist auf die Behandlung von Krankheit ausgerichtet, nicht auf den Erhalt der Gesundheit. Solange keine Risikofaktoren messbar sind, bleiben wir aber unter dem präventiven Radar dieses Systems. So lange bis es zu spät ist. Denn wer als Mann mit 45 Jahren noch frei von Risikofaktoren ist, hat eine 97%ige Chance seinen 80 Geburtstag bei guter Gesundheit zu feiern. Liegen bereits 2 Risikofaktoren vor, wie beispielsweise Bluthochdruck und erhöhtes Cholesterin, dann schrumpft diese Chance auf 50%. Und selbst wenn Sie zu jener glücklichen Hälfte zählen, die die 80 Kerzen auf dem Kuchen ausblasen darf, werden Sie genau das wahrscheinlich nicht mehr schaffen, denn eine der chronischen Krankheiten wird Ihnen die Kraft dazu genommen haben.

Die gute Nachricht: mit den einfachen Gesundheitsverhalten - nicht rauchen, ausreichende Bewegung und kein Übergewicht - können Sie heute schon bestimmen, wie Ihre 80. Geburtstagsparty ablaufen wird.

Die schlechte Nachricht: Das alles sind keine neuen Erkenntnisse. Den Kassen sind sie genau so bekannt wie den Wissenschaftlern, die sie erarbeiten. Dass Präventionsbemühungen trotzdem nicht von den Kassen finanziert werden, hat erstaunlicherweise nichts mit Geiz oder Unvernunft zu tun, sondern mit dem Paragraphen 20 des fünften Sozialgesetzbuchs. Dort schreibt unser Gesetzgeber den Kassen eine Ausgabengrenze für Prävention vor: € 2,84 pro Versichertem pro Jahr. Offensichtlich sind die Bekenntnisse unserer Gesundheitsminister zur Prävention nichts anderes als Lippenbekenntnisse.

Es sind also nicht Defizite in Wissen oder Fortschritt, die uns das Zeitalter der chronischen Gesundheit und Langlebigkeit vorenthalten. Es ist das Versagen unseres Gesundheitssystems, das Wissen einzusetzen und damit die Gesundheit endlich als das zu behandeln was sie ist, ein Wirtschaftsfaktor. Ist das nun wirklich eine so radikale Änderung der Strategie unseres Gesundheitswesens?    PrintPDF

Am I shittin' you? Learn to be a skeptic!

Learn to be a skeptic!

Why you cannot believe what you read about medical studies.

In my last blog post I promised to tell you why you shouldn't trust any study results, particularly when you didn't read the study yourself. It has to do with the methods of biomedical research. To make my point, I'll take the gold standard research method, the double blinded randomized controlled trial, or RCT. 

Let's say we want to test a drug, which is supposed to lower blood pressure in those who suffer from hypertension. The researchers have decided to enroll, say, 100 "subjects". That's what we typically call the people who are kind enough to play guinea pig in our studies.   

The researchers will first do a randomization of subjects into one of two groups (very often it is more than one group, but to keep it simple we will assume just two groups). What we mean with randomization is that we randomly assign each subject to one of the two groups. One group - the intervention group - will receive the drug, the other group - the control group - won't. What they get instead is a sugar pill, a placebo. 

With the randomization we want to make sure that, at the start, or baseline, both groups are indistinguishable from each other with respect to their average vital parameters. For example, if we were to calculate the mean age, blood pressure and any other variable for each group, these mean values would be not different between groups. That's important, because we want to isolate the effect of the drug. We don't want to worry at the end whether the effect, or lack thereof, was maybe due to some significant difference between the groups at baseline. 

Once the randomization is done, we organize the trial in such a way that neither the "subjects" nor their physicians and nurses know whether they get the placebo or the active drug. Both sides are blind to what they get and give, which is why this set-up is called double-blinded. That's an important feature, because a researcher often goes into a study with a certain expectation of its outcome. Either that outcome supports his hypothesis, or it doesn't. To eliminate the risk of, more or less subconsciously, influencing the study towards a desired outcome, double-blinding is very effective tool.

Fast forward to the end of our trial. We have now all the data in hand to compare the two groups. After unblinding, the researchers will compare the two groups with each other. In our example, they will compare the average, or mean, of the blood pressure values of all the individuals for each group. If the intervention group's mean value is lower than that of the control group, then it is plausible to reject the null-hypothesis, that is to REJECT the idea that the drug is NOT as ineffective as the placebo (we are, of course, assuming here that the sugar pill didn't lower the blood pressure of the control group). 

There are statistical tools to determine whether the difference between the groups may just be a chance event, or whether chance is a very unlikely explanation. We can never rule out chance completely. Now, when we are confident that it is the drug and not pure chance, which has lowered the mean blood pressure in the intervention group, we write our paper to present it in one of the medical journals. 

If the subject is a little more sexy, than just lowering blood pressure, there will sure be some journalists who pick it up and report to their readers that, say, eating chocolate makes you slimmer. I'm not kidding. This headline very conveniently went through the media shortly before Easter this year [1]. Good for Hershey who are running it of course on their webpage. And in the media it reads like it did in the Irish Times: "Good news for chocoholics this Easter. Medical Matters: No need for guilt over all those Easter eggs."    

I'm not going to comment on the media geniuses, because it's their job to put an angle on every story, so that YOU find it interesting and read their stuff. But since I'm sure you'll follow these links, just let me warn you: the chocolate study was an observational study, not an RCT. And one thing we MUST NOT do with the results of observational studies is to confuse association with causation. Only when we conduct an RCT, where the intervention group eats chocolate and the control group doesn't, might we be able to determine whether there is a causal link. And for obvious reasons we can't blind the subjects, to whether they eat chocolate or not. But I'm digressing.

Back to our blood pressure study. When we compare the group averages, everything looks very convincing. And sure enough, as researchers we are happy with the results, and we are perfectly correct, when we conclude, that this medicine does its job. 

But will it do it for you? When you are hypertensive? You might be wrong if you say "Yes". And you will be wrong more often than we, as researchers, or your doctors care to admit. For one simple reason: The variability of effect within the group. You give 50 people the same drug, and I bet with you, and I'm not the betting type, that you'll have 50 different results. 

The mean value of the entire group glosses over these inter-individual differences. Let me give you an example from a study performed on 35 overweight men, who were studied in a supervised and carefully calculated 12-weeks exercise program, with the intention of reducing body weight. The mean weight loss was 3.7 kg. That was almost exactly the amount of weight loss which the researchers had expected from the additional energy expenditure of the exercise program. But when they looked at each individual, it became clear that the group mean doesn't tell you anything about how YOU would fare in that program. 

First of all, the standard deviation was 3.6 kg. Now, a standard deviation of 3.6 kg simply tells you that approximately two thirds of the participants experienced a weight loss anywhere between 3,7 kg (the mean) minus 3.6 kg and 3.7kg + 3.6 kg, that is between 0.1 kg and 7.3 kg! That's a lot of kilos. And what about the remaining one third of those participants? They are even further from these values. In this case the greatest loser went down by 14 kg, and the biggest "winner" gained almost 2 kg. A spread of 16 kilos!

Here is the graph which shows you the change on body weight and fat for each individual participant. Which one would you be?

This effect is what you do not see when you don't read the studies. And in most studies, it isn't made obvious either. 

Which is why, you shouldn't be surprised to learn that most major drugs are effective only in 25-60% of their users [2]. The same goes for weight loss drugs and interventions, for almost everything we study in biomedicine. 

That's not a problem for us in public health. Because a drug, which works in 60% of the patients, helps us reduce the burden of disease in our population. Public health is not interested whether you are one of the 60% or not. But you are. And that's why I believe not only medicine, but also prevention must be individualized.

 Which is why the GPS to chronic health, which I currently develop, is all about helping you find your individual path to your health objectives.

Why not have a look at it, and maybe even try it out? 

References

1.           Golomb, B.A., S. Koperski, and H.L. White, Association Between More Frequent Chocolate Consumption and Lower Body Mass Index. Archives of Internal Medicine, 2012. 172(6): p. 519-521.

2.           Wilkinson, G.R., Drug Metabolism and Variability among Patients in Drug Response. N Engl J Med, 2005. 352(21): p. 2211-2221.

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Die Sucht aufs Essen. Warum wir dick werden obwohl wir es nicht wollen.

Unser Essverhalten wird weniger vom freien Willen und der Vernunft gesteuert, als vielmehr von autonomen Mechanismen. Den Verhaltensforschern sind sie bekannt. Den Akteuren unseres Gesundheitswesens sind sie ein Dorn im Auge. Ein Dorn, der sie mit einer selektiven Blindheit geschlagen hat für...

Die Sucht aufs Essen

Neurohormonale Mechanismen treiben den Drogensüchtigen zu seiner Droge, obwohl er die Konsequenzen seines Verhaltens kennt und fürchtet. Den Verhaltensbiologen sind diese Mechanismen seit einigen Jahren bekannt. Und auch dass Zucker dieselben Hirnzentren und Mechanismen aktiviert. Evolutionsbiologisch wichtige Mechanismen, wie wir heute wissen. Denn die Lust auf Süßes trieb unsere Urahnen zu der einzigen Nahrung, die diese Lust befriedigte: Obst und Früchte. Diese Lust war aus zwei Gründen wichtig: erstens sind unsere Speicher für Kohlehydrate, anders als die fürs Fett, sehr klein und innerhalb von spätestens 48 Stunden aufgezehrt. Zweitens liefern Obst und Früchte lebenswichtige Mikronährstoffe. Ganz im Gegensatz zu jenen Colas, Kuchen und Keksen, mit denen wir die Lust auf Süßes heute befriedigen. Für diese Lust sollten wir uns also nicht deshalb schämen, weil wir sie erst mit der Erforschung eines moralisch verpönten Verhaltens, der Drogensucht, entschlüsselt haben. Das erklärt, warum die Nahrungsmittelindustrie Zucker in allen möglichen Nahrungsmitteln versteckt, in denen wir ihn nicht vermuten. So wie die Zigarettenindustrie  ihre Tabake mit zusätzlichem Nikotin anreichert, einem der stärksten Suchtmittel überhaupt. Die Konsequenz dieser Sucht auf's Essen ist das Übergewicht. Womit wir beim zweiten Grund für das Scheitern des Abnehmens sind:

Entgleiste Hormone

Wer lange genug zu viel isst und sich zuwenig bewegt, verwandelt nicht nur seine Figur sondern auch seinen Organismus. Gemeint ist damit jene komplexe neurohormonale Vernetzung von Verdauungsapparat, Fettgewebe, Muskelzellen und jenen Hirnzentren, die Appetit, Sättigung und den Drang auf Bewegung regeln. Wer nach einem Essen, das eine vierköpfige Familie in Bangladesh ernährt hätte, der Lust auf ein Tiramisu nicht widerstehen kann, hat das auch diesem neurohormonalen Netzwerk zu verdanken. Es ist resistent geworden gegen Sättigungssignale. Wenig hilfreich ist auch, dass der Anblick des Tiramisu einen Verhaltensreflex auslöst, den wir von Boris Becker in der Besenkammer kennen. Erst mal vernaschen, bereuen kommt später. Verhaltenswissenschaftler nennen dieses Phänomen...

Hyperbolic discounting

Discounting heißt Abzinsung. Was der Verhaltensforscher darunter versteht, ist die Art, wie unser Gehirn intuitiv den Gegenwartswert eines erwarteten zukünftigen Nutzens ermittelt. Vor die Wahl gestellt, entweder 120 Euro in 6 Monaten geschenkt zu bekommen oder 100 Euro in 5 Monaten, entscheiden sich die meisten Menschen für die 120 Euro. Was aber, wenn ich Ihnen 100 Euro jetzt bar auf die Hand biete oder 120 Euro in einem Monat? Die meisten Probanden ziehen die sofort verfügbaren 100 Euro vor. In beiden Fällen ist die Differenz die Gleiche, nur Sie bewerten sie intuitiv anders. Dieser Effekt ist mit dem Wörtchen "hyperbolisch" beschrieben, einer mathematischen Formel die sich von der exponentiellen Form der Abzinsung unterscheidet, auf der wir unser Banken- und Wirtschaftssystem aufgebaut haben.

Dank der hyperbolischen Abzinsung greifen Sie morgen doch wieder zum Tiramisu, obwohl Sie heute Stein und Bein schwören, dass Ihnen der Gesundheitsgewinn in der ferneren Zukunft wirklich mehr wert sei als der Lustgewinn nach dem Mittagessen morgen. Und genauso funktioniert nicht nur das menschliche Gehirn sondern auch das von Tauben, Mäusen und Affen. Das zeigt, im Laufe der Evolution muss sich die hyperbolische Abzinsung als wirksames Werkzeug fürs Überleben bewährt haben. Andernfalls hätte Mutter Natur es nicht über Millionen Jahre in die Hirne ihrer Spezies programmiert. Heute müssen wir mit diesem Erbe in einer Umwelt zurechtkommen, deren Gestaltung wir Mutter Natur aus der Hand genommen haben. 

Dem Aberglauben an die Vernunft und den freien Willen als Treiber unseres Ess- und Bewegungsverhaltens hätten diese Erkenntnisse schon seit mehr als 10 Jahren den Wind aus den Segeln nehmen müssen. Haben sie aber nicht. Wohl weil es einfacher ist, den Dicken und chronisch Kranken die Schuld für ihren Zustand zu geben, als sich zu fragen, wie das Produktions- und Werbeverhalten einer Nahrungsmittelindustrie, von Nestle bis zu MacDonalds, zu reglementieren sei.

Und wie kann ich nun behaupten, dass das Zeitalter der chronischen Gesundheit greifbar ist?

Aus drei Gründen: weil sich die Börsen für das Thema zu interessieren beginnen, weil wir unser Hirn überlisten können, und weil wir die notwendigen Werkzeuge aus den Gesundheitswissenschaften haben. 
Dazu mehr im nächsten Beitrag. Und falls es Ihnen bis dahin langweilig werden sollte, können Sie ja schon mal einen Blick auf unser Navi zur chronischen Gesundheit werfen.   PrintPDF