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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