Thursday, May 14, 2009

The Science of Eating Food...Love It, Hate It

I've always thought of myself as something of an intuitive eater. What foods I eat, in what combinations, how they're prepared, when I eat them...it all happens on its own, in a way, without a lot of explicit thought. At least, not the kind of explicit thought that people give to food when they're on a Diet (i.e. South Beach).

My own diet (little "D") is informed by multiple sources: my family heritage (Italian, Belgian, Polish); my dietary restrictions (gluten, lactose); my love for travel (which I might lump with my heritage and simply call "culture"); my ethics (local, organic, humane, seasonal); and the regions where I've lived (the Northeast, the West). By and large, though, you'll notice that science is absent from that list - I don't depend on scientists and research studies to tell me what's good and bad for my body, and what I should and should not eat.

This, I think, is a good thing (by good I mean staying away from a heavy dependency on science for eating food). For one, such "wisdom," as in parenting, constantly seems to be changing, or the advice is self-conflicting (are eggs good or bad?). For another, "science" has given us such regrettable "foods" as modified food starch, high fructose corn syrup, imitation foods, and heavily processed foods. For yet another, science has limitations - by necessity, it is very good at looking at one very specific thing (lycopene as an antioxidant in tomatoes, for example), but very bad at looking at whole, complex systems (such as the foods we eat in combination). And, most lamentably, science has, in a way, taken away the social and cultural and historical context of food, and replaced it with a dry, intellectual, detached approach to eating.

To elaborate on the tomato-lycopene example... As scientists have continued to research antioxidants (and espoused their health virtues), those same scientists have a) taught us that lycopene is in tomatoes, and therefore tomatoes are good (was this in question?), and b) have developed lycopene supplement pills so that we can pump ourselves full of the stuff and maximize the perceived health benefit. More recently have we realized that such an approach was putting the cart ahead of the horse, in a way, and that we didn't yet understand the full picture. We've since come to learn (thank you, diligent scientists) that the unique combination of tomatoes and olive oil is a powerful combination that unlocks and magnifies the power of lycopene in the human body. This effect is not present in the absence of olive oil, and isn't present if we substitute another oil (say, sunflower) in place of olive oil.

But does the tomato-olive oil combination sound familiar to anyone? Of course it does. It's ubiquitous in Italian cooking (at least since Italians went whole hog for tomatoes when it arrived in Europe from the New World). In short, Italians have been cooking with and eating tomatoes and olive oil together for several hundred years. They didn't do it because science told them to. They did because intuitively, they simply knew that it "worked."

Another example of science acting as an intermediary between us and the foods we eat is the advent of the glycemic index (and its cousin, the glycemic load). The glycemic index refers to a food's impact on blood sugar levels. Foods with a high index cause a rapid increase in blood sugar (a spike, or sugar high). But that spike in blood sugar also triggers a release of insulin, which causes a similarly rapid plummet in blood sugar (the crash). Conversely, foods with a low glycemic index don't cause that spike, instead releasing lower levels of sugar into the blood over longer periods of time. (The glycemic load is a way of prorating a food's index based on serving size.)

Now, I'll begrudgingly admit that there is some real practicality to understanding and utilizing the glycemic index and load, especially in certain populations of people. For example, because the index and load focus on blood sugar and insulin, knowing the values for different foods can be a literal life-saving tool for diabetics. Understanding the glycemic index and load is also valuable for endurance athletes, who want to fuel their bodies sustainably, and avoid an energy crash (bonking) mid-race.

But beyond those examples, I don't much like the idea of having to evaluate my meals using a massive spreadsheet of glycemic index and load values. It takes much of the fun out of eating. And, it removes or supplants or interrupts the intuition...the learned cultural and historical and ethical contexts that inform what we choose to eat. What's more, as I said above, science is very good at looking at one very specific thing (in this case, the glycemic index for a given food), but not very good at looking at complex systems. For example, the glycemic index of a given food can vary widely depending on how the food is prepared (is that potato boiled, baked, mashed or fried?). For another example, the glycemic index of a given food varies just as widely depending on the combination of foods with which it is consumed. In the end, where does that leave us? I'm not exactly sure.

In the same breath that I criticize science and what it tells us (or doesn't tell us) about eating food, though, I also have to praise it. Science is what discovered that the gluten family of proteins in wheat, barley and rye is what makes my body sick. And science is also what gave us xanthan gum, an invaluable tool when it comes to gluten-free baking. This simultaneous criticism and praise doesn't make me a hypocrite, or guilty of talking out of both sides of my mouth, or indecisive. It simply means I have a love-hate relationship with it. That doesn't inherently make the relationship good or bad. It just is. As with the rollercoaster of life and gluten-free living, there are pros and cons, ups and downs, the good and the bad.

I've stood on my soapbox, but what do YOU think? How does science influence (or not) what you eat. Is it good, bad, indifferent? I'd be curious to hear your feedback!

- Pete

6 comments:

Amanda on Maui said...

I feel like I am in the same chapter of the book you're in on this issue.

peterbronski said...

Hi Amanda. Glad to hear I'm not alone in my perspective!

Cheers, Pete

Steph said...

I'll agree with you that some of the things science has given us are positive - ie, the gluten-free opportunities, xanthan gum, and understanding of the glycemic index (invaluable to myself as a hypoglycemic), but I'll also agree that some of the stuff they "come up with" is pretty, um, for lack of a better term, "no duh" to me. I loosly follow a mediterranean diet, mostly because that is the food that gets along with me the best. My own personal "science" is like yours, and to basically eat what works w/ you. I very strongly believe (and science, or rather, a lack of helpful doctors has added to the belief) that listening to your body is the best way to help you and keep you healthy!

glutenfreeforgood said...

Pete,

Good series of posts! I'm a food science person and I agree with you that we get too locked up in the science part, often to our own detriment. Isolating nutrients from the whole doesn't always serve much purpose as one usually depends on another to work.

I have my own little list of what constitutes healthy food and it doesn't take an scientist to figure out. Can you hold it in your hands and wash it? Would your grandmother be familiar with the food? Does it rot (which is a good thing)? And so on...

Fairly straightforward. I'm wondering about xanthan gum.

Another good post. I love science and that's my background, but gosh, we get so wrapped up in isolating nutrients and thinking that's the answer. We need to go back to the beginning. Catch that rabbit, harvest some dandelion greens, and gather some berries.

:-)

Okay, I'm skipping the rabbit thing, but I like old fashioned nourishment -- real food!

Melissa

Jeff said...

I agree completely Pete. Eating is an art not a science!

I am pretty excited about shmeat though...
http://www.npr.org/templates/story/story.php?storyId=90235492

GFE--gluten free easily said...

Another excellent post, Pete!! A lof of what you share is exactly what Michael Pollan writes about in his book, In Defense of Food.

My husband (who eats gluten) and I both have been having some, uh, issues, after eating some foods made with a gf flour mix that contains the new Expandex. If you are not familiar with it, Expandex is modified tapioca starch. The manufacturers are quick to point out that it's not genetically modified though, although they don't share the info on what the modification is ... stating that it's proprietary. Read more here: http://expandexglutenfree.com/consumers/qa.php Anyway, I've been using the gf flour that contains Expandex occasionally with no issues, but this week I had made brownies to share and both hubby and I had some before giving most away and then I'd made a chicken pot pie using this flour to thicken the filling and then to make the crust. We ate that for two days (I even ate some for lunch). All tasted great, but like I said, it caused definite issues. No specific conclusion to be drawn (except we need to avoid this product and Expandex), but it gives one pause.

I like Melissa's guidance on what constitutes food. Similarly, I think that anything that insects don't want to eat I don't want to eat.

I'm not diabetic, but I find adherence to the whole glycemic index and carb counting can steer folks down the wrong paths, too. It's similar to my thoughts on the gf specialty foods. Suddenly, you see folks abandoning real food and buying a bunch of sugar-free junk, or trading one evil (processed food) for another (sugar-free processed food!). I've seen many folks who are diabetic who do not improve, but actually get worse. I have tried xylitol and sugar-free foods before to see if they would help me go sugar free and the results were disastrous.

Folks who go on the heart diets and switch over to margarines, giving up fats (even the good ones), etc. also don't fare very well from what I've seen (through relatives). In all of these cases, the "take-home" guidance seems to be to give up real food for food that has been deemed safer by food science. Fighting that thinking is the main premise behind South Beach Diet. Dr. Agatsten (sp?), the cardiologist who designed it, saw folks go on the traditional heart diet and get worse and worse. I think the South Beach Diet is good, except for the inclusion of wheat of course. ;-)

Finally, I find it interesting that for years we talked about how our grandparents ate so much unhealthier with meals of higher fat, more meat, etc. and now recent studies (don't you hate that term? LOL) have shown they were actually far healthier than we are today. Certainly, not every illness/health problem we have today is diet induced, but the obsession with low-fat, low-sugar, etc. largely trades one evil for another and food science largely doesn't add up as a way to tell us to eat safely and well.

That's my 25 cents on that topic, and per usual I could have written more. LOL Another topic that riles me up ...

Shirley