Monday, May 28, 2012

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.
I recently gave a talk on the lies and deceptions the food industry uses in labeling and marketing their products. A German corporate health insurance had asked me to give that presentation to their clients. Naturally, a large percentage of the audience were women. Judging from the lively and entertaining discussion, which followed my presentation, almost all women prefer home cooked food for their families to take-out or eat-out. The most often cited reason was that home cooked food is the healthier choice. I'm not convinced that they get it. Not if they get their food information from where they professed to search for it: the internet.
I know this, because in preparation for my talk I followed my wife on one of her culinary search trips through the web.
The number of recipe sites is staggering. So is the degree of misinformation disseminated by them. Most of it in the form of labeling something as healthy when it clearly isn't. Let's look at three commonly encountered mis-perceptions on randomly chosen recipe sites. I won't give you the links, because to single them out would be unfair. What I found there is so ubiquitous, that you will encounter it virtually everywhere once you start surfing the culinary side of the web.

Honey vs. Sugar

A self-proclaimed holistic health counselor shares her recipe for a "Healthier Flourless Chocolate Cake". Which immediately begs the question: healthier compared to what? The answer comes in brackets directly behind the title, where it says "refined-sugar free". Reducing sugar in our daily diet is certainly a big step towards better health. But you won't get there by replacing sugar with honey. The difference between sugar and honey is simple: Sugar is 100% sugar, honey is 80% sugar. Admitted, that's a little oversimplified. Honey does have ingredients which sugar doesn't. But these are not an issue when it comes to reducing calories or the metabolic impact of sugar. Whether you sprinkle granulated sugar into the dough or fold honey into it, what your metabolism has to deal with is their common denominator, the breakdown molecule, which ends up in your blood - glucose. Of the recipe's remaining 4 ingredients - butter, eggs, cocoa powder and baking chocolate - the butter is evidence that our holistic health counselor has missed out on another common diet mis-perception:

Butter vs. Oil

On another website we find the "Best Ever Healthier Chocolate Brownies". Honey isn't an issue for this lady. Her claim to healthiness is based on the conviction that other recipes use "... butter rather than olive oil", and that "olive oil contains healthier fats". This butter vs. oil issue is not as straight forward as the glucose theme. So let's look at it in greater detail.
The fats for human nutrition come either from animal or plant sources, and you can think of them in 3 major categories: saturated fats, and mono- and poly-unsaturated fats. We don't need to go into the molecular details of the fats - or fatty acids (FA), as they are more correctly called. Suffice it to say, that the "unsaturated" part of the descriptor refers to one (mono) or more (poly) carbon atoms of the fatty acid molecule having less than the maximally possible number of hydrogen atoms linked to them. Depending on the position of the first "unsaturated" atom in the chain of carbon atoms, the poly-unsaturated fats are called omega-3 or omega-6 poly-unsaturated fatty acids (PUFA). There is one more thing you should be aware of: the human body can manufacture most of the fatty acids which it needs for its metabolism and maintenance. But there are two, which we need to supply through our food intake. These two are alpha linolenic acid (ALA), an omega-3 FA, and linoleic acid (LA), an omega-6 FA. Our organism uses them to produce other fatty acid variants which are essential for our health.
Armed with this knowledge we can now ask ourselves an obvious question: What's the health issue with fats? You have probably heard that a high fat diet promotes high levels of cholesterol in your blood (partly true) and that high cholesterol is the cause of heart disease (not true). You have also heard that saturated fats, such as butter, are bad for you and that replacing it with olive oil is good for your health.
Now let's hear the facts as we know them today: Dietary trials in which saturated fat, such as butter, was replaced by PUFA lead to a reduction in risks for cardiovascular disease [1]. However, when those PUFAs were mainly of the omega-6 version, there was no reduction, or even a slight increase in risk for heart disease. Looks like replacing saturated fats with oils isn't going to do you any good if you don't chose the oils for their content of omega-3 FAs.
These observations match nicely with what we know from evolutionary biology. Comparing the fat intake between our hunter/gatherer ancestors and us, we notice that the ratio of omega-6 to omega-3 fatty acids has undergone a dramatic change. While that ratio stood at 1:1 or even lower throughout most of human evolution, our modern western diet has upped that ratio to a whopping 16:1 [2], and even greater than that, depending on where you live. When I now tell you that the downstream products of your omega-6 FA intake are pro-inflammatory whereas the products of ALA have the opposite effects, you might begin to see the picture. With heart disease and stroke being the late-stage consequences of chronic inflammation of the arteries, as I highlighted in my earlier post "Your Shortcut To Longevity", the type of fat appears to have an effect on your arterial health. And therefore on your risk of heart disease.
How large this effect really is, remains unclear. In a recently updated review of randomized clinical trials the Cochrane Collaboration came to the conclusion that reducing the content of saturated fat in favor of unsaturated fats had some effect on cardiovascular disease events in men only (not in women) and only if such dietary habit change lasted at least 2 years [3]. There was no detectable effect on the risk of dying from cardiovascular disease. Importantly, it was unclear whether the reduction in disease events was due to poly- or mono-unsaturated fatty acids.
There is another issue I have with that song and dance about olive oil. Its omega-6:omega-3 ratio is around 13, which doesn't exactly make it heart healthy. In comparison, the much maligned coconut oil has no omega-3 FAs only omega-6. But it delivers only a third of the omega-6 FA of olive oil. In contrast, sunflower oil also has no omega-3 component but delivers almost 6 times as much omega-6 as olive oil. The only really stand-up guy in the vegetable oil department is flaxseed oil: its omega6:omega3 ratio is 0.3, which makes it as good as any of the fish oils, which are considered healthy. But don't get too excited about flaxseed oil taking over your kitchen anytime soon. It can't hide it's similarity with fish oil. I tried it. It's OK in a salad, and so are the seeds. Heat up the oil, though, and you think you are frying a cod liver. That taste doesn't go too well with a chocolate cake, or many other dishes.
So, what's the point? Of course, you can read the evidence as you like, but I wouldn't call a brownie or chocolate cake healthier when the only merit to this claim is its oil content. To me, the excess in calories is what by far outweighs the relative merits of the carriers of theses calories. Which brings me to the third issue:

Calorie Density vs. Nutrient Density

When I added up the calories for the brownie and the cake, the calorie-to-weight ratio was in excess of 4. That is, every 100 grams of these buggers deliver more than 400 calories. This nutrient density of 4 is way in excess of what man was exposed to through most of evolution. Think about it: fruits come with a ratio of 0.6, on average, vegetables with a ratio of 0.3 and game meat, the only meat available to our cave dwelling ancestors, delivers on average 200 calories for every 100 gram. We can reasonably assume that our ancestors had to survive on an overall calorie-to-weight ratio of less than 2. Add to this the fact that they expended far more calories than we do today. Just to maintain calorie balance our ancestors had to eat a much larger quantity of food than we do today. And that food, while low in calories, was packed with nutrients. So, their nutrient:calorie ratio was certainly far more favorable than ours is today.
There are many more issues which plague much of the web's culinary universe. By right, the word healthy shouldn't be anywhere near most of its places. Particularly when those places are all about eating and nothing about exercise. You can eat as healthy as you like, if you fail to exercise at the right frequency, intensity and volume, then pay-back day is almost inevitable.
How your arteries benefit from exercise, and how you can make that exercise exactly right for you with the least possible effort, that will be an issue of my next post. Until then, don't get hooked too much on the culinary web. I worked up a hell of an appetite during my recipe surfing exercise with my wife. Didn't do any good to my waist line and probably not to my arteries. But, what the hell, we need to enjoy sometimes, too.    

Kuipers RS, de Graaf DJ, Luxwolda MF, Muskiet MH, Dijck-Brouwer DA, & Muskiet FA (2011). Saturated fat, carbohydrates and cardiovascular disease. The Netherlands journal of medicine, 69 (9), 372-8 PMID: 21978979

Simopoulos, A. (2008). The Importance of the Omega-6/Omega-3 Fatty Acid Ratio in Cardiovascular Disease and Other Chronic Diseases Experimental Biology and Medicine, 233 (6), 674-688 DOI: 10.3181/0711-MR-311

Hooper L, Summerbell CD, Thompson R, Sills D, Roberts FG, Moore HJ, & Davey Smith G (2012). Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane database of systematic reviews (Online), 5 PMID: 22592684
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