Pollan on Nutritional Science

One of the many reasons I'm a big fan of Michael Pollan's work, including his latest manifesto, is that he's one of the few science journalists who emphasizes what science doesn't know. Here's an interview from Gourmet:

CH: When your piece first came out in the Times Magazine urging people to ignore all the nutritional claims and eat only things their great-grandmothers would have recognized as food, some readers accused you of being anti-science. But you do actually reference a lot of scientific studies in this book--particularly agricultural and environmental science, and quite a few nutritional studies as well. What role do you think science should play in our diets?

Pollan: Well, science has a legitimate role to play, there's no question, and biology is an important way to understand both ends of the food chain--what's happening in the plant and the animal and the soil, and also what happens when we ingest foods in our bodies. But I think science is playing altogether too large a role right now, because it turns out on close inspection to be a really primitive science. We still don't know that much about the soil, about digestion, or about the precise chemical compounds people need from food.

The way I see it, the science of nutrition is kind of where surgery was in 1650. It's promising, it's on its way to a deep understanding of what's going on, but it's not quite time to put yourself in their hands for elective surgery. We might do well to look for other sources of knowledge about food until they've got it all figured out. I'm not saying we should reject it, I just think we have to be very humble, and the scientists need to be more humble. Scientists are very bad at telling you what they don't understand.

Is nutritional science really equivalent to surgery in the 17th century? I'd put it closer to 19th century medicine. Nobody benefited from being cut open in 1650. And while I think the ideology of nutritionism is often misguided, the fact of the matter is that it has helped solve many different diseases, from scurvy to beriberi.

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And while I think the ideology of nutritionism is often misguided, the fact of the matter is that it has helped solve many different diseases, from scurvy to beriberi.

That is the key concept in this - nutrition science can be useful when looking to necessary conditions for correcting unhealthy conditions like scurvy. But merely using reductionist nutritionism to determine sufficient conditions for health will not work since health is a holistic concept that cannot be broken down completely into static elements like nutrients.

Is nutritional science really equivalent to surgery in the 17th century? I'd put it closer to 19th century medicine. Nobody benefited from being cut open in 1650. And while I think the ideology of nutritionism is often misguided, the fact of the matter is that it has helped solve many different diseases, from scurvy to beriberi.

I agree with you in bumping up the estimate a couple of hundred years. Every scientific discipline has to start somewhere and accrue a cumulative body of knowledge. I think as computers speed up so will the knowledge and models of nutrition. In the mean time they deserve credit for what has already been accomplished, as you pointed out!
Dave Briggs :~)

"Eat food, mostly plants, and not too much." This pretty much sums it up. The reason nutritionism has become so prevalent is that (1) it is so profitable, and (2) it has become fashionable/respectable. People are being sold this information, dietary products, and supplements because people are willing to pay for it.

One of the constructive roles science can play in informing our dietary choices is through evolutionary biology. As Jonah has pointed out in a previous post, the optimal diet today turns out to resemble that of an 17th century Tuscan peasant.

P.S. If you ever get a chance to visit Polyface Farms in Swoope, VA (written of in Omnivore's Dilemma), by all means do it. We did. Very pleasant if bewildering drive out there, and interesting farming operation--you can tour it on your own.

Re Alan's comment: Or as a famous but, sadly, dead French comedian used to say, if people weren't buying it, it would no longer be sold.

The appeal of nutritionism and supplements and all the rest is also related to ease. People are being sold the idea that they can eat whatever is easiest and supplements will fill in the nutritional gaps.

The diet of the 17th century Tuscany peasant is certainly the healthiest, but many don't seem to want to take the time to cut and peel vegetables and all that. We have big shiny kitchens with the latest in gadgetry, but we eat one-third of our meals outside the home. And we eat on the run, instead of taking the time to prepare food and sit down to eat it.

One of today's most bizarre ads is the one for a fast-food chain specializing in chicken. The voiceover talks soothingly about getting your family together for a sit-down, homestyle meal, which turns out to be bucketfulls of unsavory, unhealthy, deep fried fast food!

Re: Peggy's comment on my comment. You caught the circular reasoning red-handed, and were nice about it. Kindness is always appreciated. Who was the French comedian, if I might ask?

Here's some food for thought, pun intended, on a tangential issue--dietary laws. In some of his essays, Stanford's Robert Sapolsky discusses rituals of eating and suggests that they may reflect the need for control and identity reinforcement in our sometimes unstable environments. While I'm not of Jewish heritage, I have good friends who are, and whose families have followed kosher practices. This is a fascinating area of potential research.

There are certainly restraints on our mealtimes as never before, and the point is correct that we tend to eat on the run at least 1/3 of the time. But are we giving ourselves at least the illusion of dietary control by virtue of taking supplements, many of which have not panned out to be nutritionally worthwhile? In other words, is there some placebo effect that we get out of supplements? I would have to guess the answer is yes. Another good book is by Jay Olshansky entitled, "The Quest for Immortality." He concludes that there is no need for supplements, and practices what he preaches.

to Alan: I love reading Sapolsky's writing! I'll have to look up those essays.

But are we giving ourselves at least the illusion of dietary control by virtue of taking supplements, many of which have not panned out to be nutritionally worthwhile? In other words, is there some placebo effect that we get out of supplements?

There is definitely a placebo effect involved with using supplements. Speaking of culture, I grew up with Korean culture, which extols the virtues of eating large amounts of food, and my mother raised us to think of "balancing" the types of food we ate. This was fine when I was eating lighter Asian food at home, but when I went to college, that eating paradigm got me in trouble when used for late-night fast food runs.

After graduating, I made a conscious effort to change my eating habits, and the only way to break myself of the "eat more or you'll be malnourished!" conception was to take vitamin supplements. Accurate or not, it freed me from worrying about not getting all the nutrients I needed and let me "reset" my portion size calibration. I've been able to maintain my lower weight ever since because of the radical shift in paradigm that was faciliated by the placebo effect of vitamins.

So my answer is that while vitamins probably act largely due to placebo, it is not necessarily a bad thing if the user is highly aware of what they are seeking and recognizes the placebo effect for what it is.

To SabrinaW: To save you some time looking up the reference, I believe the Sapolsky essays I refer to were in the compilation entitled, "The Trouble with Testosterone." He's also put out some fine essays in a recent collection entitled, "Monkeyluv." All readers of this blog may also be interested in "On Deep History and the Brain" by Daniel Lord Smail, an historian, now at Harvard.

Mainstream medicine is coming to recognize the therapeutic effectiveness of placebos. According to the January 2008 issue the Journal of General Internal Medicine, almost half of Chicago interns interviewed indicated that they prescribed placebos, or sugar pills. I would guess that relief from worry is a major salutary effect, and that it feeds a positive feedback cycle of reinforcement of the expectation of an enhanced sense of personal well-being.

Interesting parallel observations on your Korean upbringing. Growing up in mainstream Anglo-American culture in the 60's and 70's, we were incentivized by our parents (one of whom had lived in Korea for a time) to eat what was on our plates by imagining all the people in Asia who would love to have such "good" food. This I now view as somewhat ironic, given what we now of the typical American diet. I am happy to see a rediscovery of in this country of the benefits of eating a variety of foods in proper balance, just as your mother wisely exhorted.

Having abandoned any deep conviction in the nutritional value of dietary supplements, I still take one or two--for the placebo effects you outlined.

Michael Pollan pretty much sums up my views on food. I love his writing style and have really enjoyed his books. He was in CT on Monday to give a talk 30 minutes from where I live - and I couldn't go at the last minute.

I consider what I eat to be a political statement and I do take every opportunity to (politely of course) be open and upfront about my beliefs. I wish there was a word to describe the philosophy that Pollan writes about. I sometimes call myself a vegetarian but that's not accurate. Flexitarian does not sound right. Locavore doesn't do it either. How about "omnivore"? I think if there was a word that was readily understandable, connotations like local/humane/enjoyable/healthy/varied/whole/unprocessed/mostly plant - and oh-my that was a lot of descriptive words - could be easily conveyed in conversation. It is inaccurate for me to tell a host that I am a vegetarian, and it is rude for me to tell them that I sometimes eat particular kinds of meat but that I won't eat what they are serving. The lack of an identifier makes it rather time consuming to describe my choices when people inquire. (Just the other day, someone caught a reference and said, "Oh, do you eat bacon?", "Well, not exactly. Yes. Sometimes. But only...")

I think the comparison to surgery in the 17th century is interesting. Although, do you think one day nutrition science will work for us eventually?

My personal view is that we have something to learn from it (look! no more scurvy!), but that "nutritionism" is too often over-interpreted. I was especially interested when Pollan pointed out (in Manifesto) that our bizarre food choices might arise from an unrecognized - and uniquely American - urge to define some kind of culinary culture. The French and Italians don't need fat free cheese because full fat cheese is part of their culinary identity. Could Americans be American without Diet Coke, Velveeta and Hamburger Helper? I'm not sure what it would take to separate such over-processed, non-food junk out of our national diet, but vague and often conflicting warnings about health effects that occur 20 years down the road just won't do it.

Alan, the French comedian was Coluche and here is what he said:
Quand on pense qu'il suffirait que les gens n'achetent plus de saloperies pour que ca ne se vende pas!

I'm not sure your reasoning was circular, really. There is an insoluble chicken-egg (pun intended as well) aspect to this issue. We buy it because it is sold to us; it is sold to us because we are willing to buy it.

Speaking of France, vitamins and supplements have been much less prevalent than in the US up to now. People go on vitamin "cures," Vitamin C for example, at certain times of the year, which last for a couple of weeks. The only people I know in France who take multi-vitamin supplements daily are foreigners, usually American. Of course, in a global world this too is changing. McDonald's and Starbuck's are popping up all over the place, and dietary habits are looking more and more like those of the 21st century US teenager and less and less like those of the 17th century peasant in Tuscany.

As a postscript to my comment above to Alan, before he died Coluche founded Les Restos du Coeur, an organization dedicated to providing food and meals to the poor. resonatedm

I consider what I eat to be a political statement and I do take every opportunity to (politely of course) be open and upfront about my beliefs. I wish there was a word to describe the philosophy that Pollan writes about.