The Food Demand Survey (FooDS) - June 2013

I previously blogged about a new survey project that started up last month.

The results of the June survey are summarized here. 

A few summary findings: 

• Meat demand appears to be down relative to May
• People have heard more about GMOs and less about Bird Flu in the last month  
• The biggest food challenge remained "finding affordable foods that fit within my budget." 
• We had some new results on natural foods that I discussed earlier. 

Criticizing Technology

If you don’t want to see skeptics and libertarians “taking the side” of “big corporations,” don’t base your criticisms of them on false assertions and pseudoscience. Get your facts straight at the outset, and don’t argue beyond where they will take you. Skeptics don’t have any particular love for industrial giants, either, but what we don’t tend to do is use reasoning that guarantees a certain outcome, regardless of the evidence. Here’s how most reactionary, Luddite thinking works:

1. Assume any new product or technology is guilty until proven innocent.
2. Deny any evidence that could prove it innocent as fabricated.
3. Dismiss critics as deluded or paid off.
4. Invent a conspiracy to explain a lack of mainstream scientific support.

This kind of reasoning is absolutely impervious to reality, and it can be used support any position, no matter how absurd. Whenever you see an insular arguments like this, it’s almost guaranteed to be wrong. Don’t assume what you’re trying to prove–unless you’re trying to prove you’re an idiot. You shouldn’t confuse questions about the science with questions about a particularcompany, and don’t embrace any argument, no matter how appealing, until you are sure of its validity.

That's from Daniel Bier at the Skeptical Libertarian Blog.

Study shows GMO feed improves liver health in pigs!

Curiously, that it not the headline that is circling the web.  Rather, the headline in credible (but uncritical) news agencies is "Scientists say new study shows pig health hurt by GMO feed."

Wow!  Sounds scary.  I had to check it out.  The claim comes from a study published in the Journal of Organic Systems (you can find it on the author's web page).  My first thought was: A journal that essentially promotes organic is not exactly credibility inspiring.  But, the study should speak for itself and I read it.  

What you'll find is, by and large, a fishing expedition.  The authors fed one group of pigs a diet of GM corn and soy and another group of pigs a diet of non-GM corn and soy.  They then tested for differences between the two group.  Here's where the problem comes in.  The authors didn't set out with a specific causal hypothesis - they simply tested for differences in everything from liver size to body weight to the headline-grabbing stomach inflammation.  I counted more than 40 different p-values coming from tests in the paper.  Just by chance, the authors would expect to find one or two significant differences and that's exactly what they found.  Out of the 40+ tests conducted there were two p-values less than 0.05 (at 5% level of significance, you'd expect 1 test out of 20 (or 2 out of 40) to be significant just by chance).  One significant result showed higher proportion of pigs with "severe stomach inflation" in GM fed pigs than in non-GM fed.  The other showed a elevated levels of GGT (a signal of liver problems) in non-GM fed pigs relative to GM fed.   

To me, the take home message is that there is no difference in GM and non-GM fed pigs that is not attributable to chance (the authors would need to correct their p-values for multiple comparisons to truly say this is non-random; they'd also need a causal theory for why one result is significant while 40+ are not).  Oddly, the only result that they find significant and gets played up is also one of the ones that is not an "objective" measure but is one in which veterinarians have to make a judgement call as to which stomachs are inflamed and which are not.  If you add together the severe and moderately inflamed, what you find is that 52% of non-GM feed pigs meet this condition and 56.9% of GM feed pigs meet this condition - a difference that is unlikely significant (moreover, a higher percent of GM fed pigs (11.1% ) had no stomach inflammation as compared to non-GM fed (5.4%).  Again, the authors need to do some kind of joint test of significance across all 4 inflammation categories. 

Unfortunately, this study, much like the previous French-rat study will be used uncritically by anti-GMO activists, and it wont be taken in the larger context of the hundreds of other studies showing no differences.   

Although the paper should stand (or fall) on its own merits (or demerits), it is sometimes useful to look at author connections.  And even though no conflicts of interests were declared, Mark Lynas points out on his blog that these are hardly disinterested parties. Among other issues,  the funding comes from a company promoting non-GMO "natural" food.  For other critical analysis see the Lynas blog as well as this one.

What do farmer's market chickens, motorcycles, and unpasteurized milk have in common?

A friend sent me a link to a new study in the journal in the Journal of Food Safety. The study shows that 90% of the chicken sold at a farmer's tested positive for Salmonella.  By contrast, only 52% of non-organic grocery store chickens and 28% of organic grocery store chickens tested positive for Salmonella.  In addition, the study found that for another illness-causing bacteria, Campylobacter, 28% of farmer's market chickens were positive but only 8% of non-organic grocery store chickens and 20% of organic grocery store chicken.  So regardless of whether you buy conventional or organic chicken at the grocery store, it is likely safer than that bought at the farmers market (at least the farmers analyzed in this study).   For one bacteria (Salmonella), organic is safer, for another (Campylobacter), conventional is safer. 

Why is this result interesting?  Because the findings are likely to be strongly at odds with most people's beliefs.  I suspect (but do not know for sure) that if asked, most people would say they think foods from farmers markets are safer than from grocery stores.  They would also likely assert organic is safer than conventional.  Yet this evidence (and other studies like it) is at odds with people's beliefs.  

I don't have a problem with people eating at farmer's markets.  Go for it!  But, ideally one should act knowledgeably, knowing full well the risks they're undertaking.  And I fear all the hype often causes people to mis-perceive the true benefits and risks of conventional, organic, and local foods.  

A similar problem exists with unpasteurized milk (or raw milk).  Although it is illegal in many states, many people want to buy unpasteurized milk.  Again, I say go for it (as long as they are two consenting adults; kids may be a different story at least if they're not your own).  But, let's not be glib about the safety risks.  Sure, it might be possible that pasteurization kills some healthy bacteria but it is certainly true, and scientific studies clearly show, that pasteurization kills illness-causing bacteria.  

So, why do we have government regulations that ban unpasteurized milk but promote farmer's markets?  Maybe the risks are larger or are more well known in one case (raw milk) than the other (farmers market meat).  One of the proper roles of government, I believe, is to provide objective-science based information.  What people do with that information is up to them.  But, it does bother me a bit when certain foods attain a moral status that causes people to under-estimate risks and over-estimate benefits.  Kahneman talked about this problem in his book Thinking Fast and Slow: something that seems good is therefore perceived unrisky and vice versa.  It also troubled me that many calls for food policies by food activists seem to be based on inaccurate perceptions of risks and benefits.  

What does this have to do with motorcycles?  Regulations in many states don't allow people to ride without helmets (helmet-less riding is banned) .  Clearly, riding a motorcycle without a helmet is risky.  How much riskier is it than eating farmers market chickens or drinking unpastuerized milk?  I don't know.  Strangely, in Oklahoma, we allow motor cycle riding without a helmet.  But, sales of raw milk in grocery stores is banned (my understanding is that it can be bought direct from the farm in OK).  So, people are presumed smart enough to weigh the risks of riding a motorcycle without a hat but not smart enough to buy raw milk from a grocery store?  Seems like a consistent paternalist would outlaw both.  Or a consistent libertarian would make both fully legal.  Either way, shouldn't we all want the best information to make choices?  

What is Natural Food Anyway?

At little over a month ago, I discussed some of the ongoing legal challenges that are swirling around "natural" claims on foods.  One of the big challenges is that the word "natural" is nebulous and is vaguely defined by regulators.   

I thought I'd try to shed a little light on the subject by making use of the survey project I just started and asking consumers what they think the word means.  In June, I added two questions to the survey.  The first question listed 10 statements and individuals had to place them in a box that said "I believe foods containing this ingredient are natural" or one that said "I DO NOT believe foods containing this ingredient are natural."  The order of items was randomized across respondents (sample size is 1,004, demographically weighted to match the US population, sampling error is about +/- 3%).  

The results indicate that most people think added cane sugar, salt, at beet sugar are "natural" but HFCS, sodium chloride, and biotechnology are not.  Interestingly, salt and Sodium Chloride are the same thing!  Yet, using the technical/scientific name reduces the % perceiving salt as natural from 65.6% to 32%!

Processed foods are seen as least natural.  "Processed food" is also a vague term.  Is cheese a processed food?   

The second question I asked was the following, "Which of the following best fits your definition of 'natural food'?"  I gave four options, and here is the % of respondents choosing each option.

The majority of respondents thought that the best definition (at least among the four I included) was, "fresh foods with no added ingredients and no processing."  

I suspect many of the foods sitting on a grocery store shelf that use the word "natural" do not meet this definition consumers found most descriptive.