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So What if the Poor Eat More Salt?

A new study was released showing that poorer people in Britain consume more salt than the rich.  I don't doubt this is true.  But, I seriously question the inferences drawn by the researchers and other commentators.

The authors of the study indicate that:

These results are important as they explain in part why people of low socio-economic background are more likely to develop high blood pressure (hypertension) and to suffer disproportionately from strokes, heart attacks and renal failure.

Really?  Isn't poverty correlated with a bunch of other bad things that can result in adverse health outcomes?  There is strong evidence that the poor smoke more, drink more, eat fewer veggies, weight more, and on an on.  Yet, we are to believe that the culprit for all their problems is salt?  Aren't there underlying factors, such as the evidence that the poor have lower discount rates (i.e., they value the future less), that are driving all these behaviors?  In short: correlation with salt intake and poverty doesn't  prove anything is causative.  Yet, we'd need to know causation before public policies are recommended.  Nevertheless, the researchers say that:   

widespread and continued food reformulation is necessary through both voluntary as well as regulatory means to make sure that salt reduction is achieved across all socio-economic groups.

But, where is the evidence that such regulations or voluntarily actions would have the intended effect?  There is actually quite a lot of debate (see here or here) about the health impacts of reducing salt in our diet.  

And what would be the costs of such voluntary or forced actions?  It might do good to ask why the poor eat more salt in the first place?  One answer is alluded to in the press release: the poor are much more likely to work in jobs that require manual labor.  You know - jobs that make you sweat.  More sweating requires more salt intake.  Another answer, also alluded to in the press release, is that the poor might eat more processed food which often contains more sodium.  What the release fails to discuss is that, given job and family demands, the value of convenient, processed food might be relatively higher among the poor.  Restricting access to such foods might very well reduce salt intake but it is unlikely to make their life measurably better.  It is easy for a relatively rich researcher with a relatively flexible job to say that the poor would be better off if they cooked more fresh foods and stayed away from convenient, packaged foods.  I suspect a single mother working two jobs would have a different opinion.

Pollan's Advice and Kahneman's Warning

I enjoy reading Michael Pollan’s books, such as The Omnivore’s Dilemma.  He is a great writer and story teller - so much so, in fact, that his arguments sort of sneak up on you.  I often find myself agreeing with his premises and conclusions without the conscious stepping in to argue the points.  In fact, a few years ago when I finished reading The Omnivore’s Dilemma, I only had a nagging feeling that something was amiss, but it took several months of reflection to systematically figure out what it was (The Food Police boils down my thoughts on it – primarily chapters 2 and 9).

I see that Pollan recently gave an address to the American Historical Association.  He asked the audience:

Why do people like me who use your work end up selling more books than you do?

His advice?

Write in a human voice, he encouraged. Embrace storytelling techniques like scene-setting, suspense, and personification.

Almost everyone more enjoys reading a good story to an academic treatise.  But one should take caution.  A good story does not equate to a true story.  I recently finished reading the book by Nobel Prize winner Daniel Kahneman, Thinking Fast and Slow.  Kahneman routinely points out that we humans are suckers for a good story.  We fit together (sometimes spurious) facts to create a coherent account that is pleasing to the mind – not because the facts actually fit together this way but because that’s how we are psychologically wired.  Here are a couple quotes from Kahneman (pg. 239):

We are confident when the story we tell ourselves comes easily to mind, with no contradiction and no competing scenario.  But ease and coherence do not guarantee that a belief held with confidence is true.  The associative machine is set to suppress doubt and to evoke ideas and information that are compatible with the currently dominant story . . . It is therefore not surprising that many of us are prone to have high confidence in unfounded intuitions

And (pg. 199):

In The Black Swan, Taleb introduced the notion of narrative fallacy to describe how flawed stories of the past shape our views of the world and our expectations for the future.  Narrative fallacies arise inevitably from our continuous attempt to make sense of the world.  The explanatory stories that people find compelling are simple; are concrete rather than abstract; assign a larger role to talent, stupidity, and intentions than to luck; and focus on a few striking events that happen rather than on the countless events that failed to happen.  . . . Good stories provide a simple and coherent account of people’s actions and intentions.  You are always ready to interpret behavior as a manifestation of general propensities and personality traits – causes that you can readily match to effects.      

My take: if you’re trying to write a book to convince readers and gain sales, you’d better try to tell good stories.  However, if you’re a reader, you have to beware that good story telling can mask weak arguments and hide important relevant facts that should be considered.  The more one becomes engrossed in a story, the more they should be on guard for the narrative fallacy or, as Kahneman puts it, the biases associated with associative coherence.

 

Are Fruits and Veggitable Subsidized?

To hear food pundits talk you'd think that growers of fruits and veggies don't receive subsidies from the government.  Indeed, the pundits often argue vegetables should receive subsidies because they don't receive them now.  Just to give one example, here is Mark Bittman writing in the New York Times:

Simply put: taxes would reduce consumption of unhealthful foods and generate billions of dollars annually. That money could be used to subsidize the purchase of staple foods like seasonal greens, vegetables, whole grains, dried legumes and fruit.

It might come as a surprise, then, to hear that many fruits and vegetable growers already receive (implicit and explicit) subsidies of one form or another.  Here is an issue, for example, that came to light during the fiscal cliff debate:  

Many folks have picked out the extension of "market loss assistance" for asparagus farmers, for example, but this dates back to the farm bill from the last year of the Bush administration. Senator Patty Murray (D-WA) brags about it on her website and Senator Maria Cantwell (D-WA) was talking about fighting for it back in 2007, so I think we can gather than a lot of asparagus is grown in Washington State.

This is said to be needed because American asparagus farmers have been "devastated" by cheap imported Peruvian asparagus.

The reality of farm and food policy and its impacts is much more complicated than is often made to appear in foodie books and blogs.