Middle Ground Meat?

Greetings, omnivores.

Today I'm going to talk a little about animal welfare, and how we might improve it without getting angry at anyone.

Lately some animal rights protesters have been harassing someone close to me (I'm not going to go into details), and it started me thinking about ways in which animal rights activists might improve animal welfare most effectively. I think there are two main inefficiencies with current animal rights activity: extremism and lack of perspective.

Problem 1: Animal Rights Activists Tend to be Extremists

"You catch more flies with honey than you do with vinegar...*"

There are three general stances you could take on animal welfare:

1. Animals suffering is equivalent to human suffering, so feed lots are equivalent to the WWII concentration camps (reflected in some ad campaigns).
2. Animals are cute but tasty: let's try to make them reasonably happy as long as we can still eat bacon.
3. Animals are here for human use. Some animals (mosquitoes come to mind) use us without the slightest regard for our well-being, so to hell with our looking after them.

While you can legitimately defend all of the above ethically, those who take stance #1 often feel entitled to, say, bomb the houses of animal researchers. While I acknowledge that you can't "prove" any value system is right or wrong, in general it's a good idea not to espouse any belief system which tells you it's OK to murder, for practical (if not ethical) reasons.

Even if you do believe murder is justified in a few circumstances, it's bad PR to kill your enemies. Homicide undermines your soft power like nothing else. I bet the above bombing did more to inoculate potential animal rights supporters than the combined forces of all the starched-shirted science-defending geeks ever to mumble through a justification of animal use at every cocktail party the world has seen.

Problem 2: Animal Rights Groups Lack Perspective

There are over 250 million egg-laying hens in the United States: almost one per human. There are likewise millions of dairy cows and livestock pigs. Many of these animals suffer for the sake of thrift: it's cheapest to pack animals into the smallest space that won't kill them.

Still, the three biggest animal rights causes I hear about are fur, pâté de foie gras, and medical research. A more quantitative statement: a Google search for "fur activism" turns up more hits than "laying activism."

What do fur, foie gras and medical research have in common? Not everybody comes home from their day quantifying drug toxicity to grab their mink stole on their way to a nice bistro: animal rights activists figure they can win more sympathy from people to counter less-common animal uses. They even turn poverty into a virtue: most of us can't afford blue fox coats while we're starting out, but PETA would have us believe we haven't yet bought fur because we instinctively know it's wrong. Moreover, a lot of rich people feel guilty about being rich (I can treat the root of this problem, incidentally. Please leave your contact info below.), making it easier to attack the morals of self-doubting millionaires.

In short, animal rights groups attack fringe animal usage since these are the issues they think they can "win." If I were them, and if I were really interested in animal welfare, I would recognize that many of us want to reduce animal suffering and would pay to do so (at least a little), so what we really need to do is have animal rights organizations set up a scoring system for farm animal welfare.

A lot of people would pay 20¢ more for eggs from hens which suffered 50% less pain. However, we have no way of really knowing how good each farm is. The time has past (or hasn't yet come) to paint each farmer Joe as a miniature Hitler: what I'd like to see are livestock comfort ratings on beef, milk, pork, chicken and eggs. Make them fair and standardized, and just watch if you don't find a significant minority of consumers support farms that would improve the lives of tens of millions of our fellow creatures.

Conclusions

Polarizing the debate on animal usage is a losing strategy: too many of us won't give up using animals in some form. Many animal activists use terrorist tactics to intimidate minority animal users. Regardless of whether you think animal rights should be equivalent to human rights, it's a better strategy to use market forces to relieve some suffering from mainstream animal uses; that's the easiest way to reduce animal suffering overall.

Chomping tenderly,

LeDopore

Reader poll: Who's a vegetarian, and why? How much extra would you spend on your daily food knowing your meat animals suffered less? How many of you would like the taste of happy meat better, if only through the placebo effect? Please leave me comments.

* Maybe animal rights activists think of the stuck fly's suffering, and so use vinegar deliberately to warn them from the trap?

"-", not "/": In Search of Luxury on the Cheap

Greetings, lotus eaters.

It's been a long time since I've done a post! Let's start this one with some raw data.

Item	Egg	Chocolate	Cheese	Wine	Car /day
Cheap Price/Serving ($)	.15	1	1	3	10
Expensive Price/Serving ($)	.85	5	7	20	60

Today's post is about how to achieve luxury on the cheap. Some people would approach this subject by talking about secret bargain-hunting techniques: how to obtain the latest and greatest without paying through the nose. However, an often ignored avenue to getting a taste of the "good" life is to spend the money where it counts the most. Something that's worked for me is to start using more of the "-" sign on my mental calculator and less of the "/" sign. Let me give an example to explain what I mean.

Eggsample

Let's talk egg selection. My local supermarkets sell eggs for as little as 79¢ a dozen. These eggs are of decent quality in that they're not risky to your health but, since they're made with such narrow profit margins, every choice the farmer makes has to maximize quantity, not quality.

In the same supermarkets it's possible to buy artisanal eggs for about $5 a dozen. Nestled in post-consumer-recycled cardboard carton packaging on which is printed (in natural, organically-farmed vegetable-based dyes) idyllic odes to the chicken pastoral ideal, these poultry-gems might not quite live up to their billing. However, in this humble blogger's opinion a free range egg is a cut above a factory-farmed egg.

Where Classical Economics Fail

The consumer is left with the following dilemma: should she buy eggs which are six times as expensive, even if they taste better? In an ECON 101 class, the critical question would be "do I enjoy the expensive eggs six times as much?". Since I'd derive less than six times the pleasure from a free-range egg meal than from a factory farmed meal, classical economics says that my utility-to-cost ratio is higher for the cheap eggs, so I should buy those. Many shoppers I see have an ECON 101 attitude as well: they eschew the good eggs because they cost a whopping 6 times as much as utility-grade eggs.

Classical economics however fails as soon as one realizes demand for breakfast is woefully inelastic. In fact, my demand for eggs is met after spending such a minuscule fraction of my capital acquiring them that neglecting the inelasticity of my appetite is absurd. Assuming you have about 2 eggs per serving, the extra cost of having free-range eggs is only 70¢. Is it worth a 70¢ premium to have superior-quality eggs? Absolutely! And yet in the supermarkets I see shoppers clamoring for the best bargain eggs. Why are people being so cheap?

Using the "-" Sign

The root of the problem is the division operator. People balk at the idea of spending six times more, while their finances are affected not by this multiplicative factor but by the arithmetic difference between prices.

From the table at the start of this post, you can see that while the relative price differences between the cheap and expensive items tends to be about 6, the arithmetic differences vary wildly. The premium on buying high quality eggs is two orders of magnitude less than the premium on driving a sports car on a daily basis. Are you willing, therefore, to sacrifice about 100 free range egg-level luxuries each day for the privilege of driving a sports car? If not, you should follow my lead: splurge on the cheap stuff and skimp on the expensive stuff.

Enjoy the good life!

LeDopore

Cookie Dough: Cold Killer?

Greetings, bowl-lickers.

A friend of mine who enjoys the odd clandestine spoonful of uncooked cookie dough suggested to me last night that I look into the risks involved in his filthy habit. (Just kidding - I regularly eat raw cookie dough by the scoop.)

We're told never to eat cookie dough because raw eggs may contain the bacterium Salmonella enterica, which can make you sick. Despite all the warnings, cookie dough eating is rampant in North America. Does cookie dough cause widespread poisoning deaths, or is it just another paper tiger? Read on to find out.



Salmonellosis: Symptoms and Rates

Any medical condition with a Latin name sounds scary. However, the majority of Salmonella infections cause gastro-intestinal upset and a fever for 4 to 7 days and then go away without formal medical intervention. If you're old, an infant, or have a weak immune system, you could need antibiotics to make your infection go away, and a particularly bad Salmonella infection can cause lasting conditions like arthritis or death. However, these big-ticket fears are relatively uncommon; this CDC study says the ratio of illnesses to hospitalizations to deaths for nontyphoidal salmonellosis is roughly 2,426 to 28 to 1.

The same CDC study estimates that the number of cases of salmonellosis in the United States is about 182 000 per year, or about 1 in 1 500; but since most infections go unreported it's really hard to tell. Its best guess is that salmonellosis from shell eggs causes about 2000 hospitalizations and 70 deaths per year: in other words, salmonella from eggs is about 1000 times less deadly than the flu (from this .pdf, page 2; this comparison is apt since both flu and salmonellosis are grave threats mostly to people with compromised immune systems).

Is Cookie Dough a Big Culprit?

Most of the salmonellosis outbreaks that make the news come from large-scale slip-ups where dozens of people get ill, rather than from small families tasting the occasional batch of cookie dough. Is this just because it takes a certain number of cases before a story is newsworthy, or is there another cause at work?

This CDC page warns that in large-batch recipes where 500 eggs are used the Salmonella risk is greater, since one contaminated egg could taint the whole batch. So what's the risk of getting salmonellosis from eating cookie dough from a two-egg recipe?

This study estimates that only 1 in 30 000 eggs is potentially contaminated with Salmonella, so at most there is a 1 in 15 000 chance that your dough is going to have any Salmonella bacteria. (If the first egg doesn't have Salmonella, the second egg has a smaller than 1 in 30 000 chance of having it too, so 1 in 15 000 is an over-estimate of the risk.) Assuming that it's certain that you will catch an infection from tainted dough, that puts your risk of death from tasting the dough at less than 1 in 36 million; if you have a healthy immune system your risk is considerably smaller. The daily chance of getting a flu as bad as a non-fatal flu-like Salmonella infection are 1 in a few hundred, so you really don't need to worry about salmonella from cookie dough: background risk levels are much higher.

EDD, LED and GHAF

Let's put that 1 in 36 million figure in perspective. The Equivalent Driving Distance (EDD) is just under 2 miles (for those new here, that means a 2-mile car trip is as likely to kill you on average as eating 2 raw eggs) and the Life Expectancy Decrease (LED) is less than 37 seconds (eating 2 raw eggs decreases your life expectancy by only 37 seconds - here I assumed on average my readers might have 42 years left in life and divided by 36 million). For more on the LED and EDD risk metrics, see this introductory blog post and this wiki page for recording risk levels.

So on average the risk of being killed by your baking is negligible. But is the fear over-hyped? Considering there are 294 000 Google hits for "salmonella raw eggs America" and only 70 Americans die of Salmonella from raw eggs, the Google Hits per Annual Fatality (GHAF) hype-metric is 4 200: about as high as for West Nile virus. (See an introduction to the GHAF metric here and a list of GHAFs for various risks here.)

Conclusion: Lick On!

Eating cookie dough gives you a negligible risk unless you have a particularly weak immune system. Whip yourself up a batch and eat it all: it really doesn't matter. Oh, and please save me a spoonful while you're at it.

Bon Appetit!

LeDopore

Taking Ears Off Your Life

Greetings, colonels.

Today's post is going to look at some of the dietary consequences of US corn subsidies. The United States corn industry is politically untouchable since so many processed foods are made from corn derivatives. (If you're interested in more details about factory foods, I thoroughly recommend Michael Pollan's book The Omnivore's Dilemma.)

While many wary eaters know that corn products like corn-fed beef and high fructose corn syrup (HFCS) are wrecking dietary havoc among the American people, it's difficult to assault the entrenched food industry without convincing facts about just how much direct damage corn subsidies do to our health. In this post I'm going to show that we can blame pretty much all of our HFCS woes on corn subsidies, and I'm going to show how much damage HFCS really does.

Corn Subsidies

Ever since 1975, the United States has been paying farmers to grow corn in excess of the quantities which the market would naturally bear. Taxpayers make up the difference between the market price and a government-guaranteed price, which is often in the neighborhood of twice the buying price of corn. Americans pay over $5 billion per year (about $17 per capita) to keep farmers producing way more corn than we could ever safely consume.

Consequences of Corn Subsidies

Corn farmers aren't the ones getting rich; the net effect of corn subsidies is to ensure a huge surplus of raw biomass to be used to manufacture higher-value food products. From The Omnivore's Dilemma, I learned that about 60% of the corn grown in the United States goes to animal feed, and much of the remainder goes into producing HFCS. If you drink diet soda or if you steer clear of US-grown meat, your taxes are paying for someone else's unhealthy diet. (Show of hands: would anyone out there resent subsidizing tobacco?)

HFCS Created by Corn Subsidies

If I'm going to accuse subsidies for making us eat unhealthy corn and corn-fed meat, I'd better be sure the subsidies are actually to blame. There are three factors which make methink corn subsidies are the root cause of pretty much all the HFCS consumed by Americans. First, HFCS is cheaper than cane sugar in the US due to subsidy. Second, in Europe, where corn isn't favored like it is in North America, HFCS is almost never used as a processed food sweetener. Third, the timing of the introduction of the corn subsidy coincides with the explosive growth of HFCS consumption in the US, as is evident in this graph (from this USDA site):



Corn subsidies were introduced in 1975, before which it's plain that HFCS was a bit player. Also note that soft drinks began phasing in HFCS as a sweetener, a transformation completed by 1984. (I fancy I can see the kink in the HFCS curve around 1984 - I wonder if that's caused by saturating the soda market.)

Fat Caused by HFCS

If HFCS were like normal unhealthy food, at least a calorie of HFCS consumed would displace a calorie from some other source, meaning that HFCS wouldn't be more responsible for today's obesity epidemic than any other unhealthy food. However, as I mentioned in this post, a recent study showed that HFCS doesn't make you feel full, so consuming HFCS will not make you eat less of other things. (The 95% confidence limit to this study was that 100 HFCS calories may displace 24 other food calories, but the study's best estimate is that people actually eat 17 more calories of other foods for every 100 HFCS calories they consume. Also note that other liquefied sugars may be just as bad as HFCS at displacing other calories.)

Even if you take the most charitable view towards HFCS allowed by the study's margin of error, 76% of the HFCS calories consumed by Americans go to fat. The average annual per capita consumption of HFCS in the United States is 59 pounds. Even assuming half of that gets wasted, that means annually an extra 22 lbs of sugar per American is consumed just because HFCS happens to be today's sweetener of choice. According to this publication (page 13 - also interesting because it claims HFCS might be not worse than other liquid sugars), HFCS is about 4/9 as calorie-dense as fat, so the availability of HFCS means that on average Americans gain an extra 10 lbs per year.

Conclusion

On average, $17 of your taxes every year go to a subsidy which causes people to gain an astonishing 10 lbs per year just through the HFCS mechanism I've outlined. (I expect subsidized animal feed also makes Americans fatter, but the story there is harder to untangle.) Moreover, the over-fertilized Iowa corn monocultures are horrible on the environment, and have killed Mexican farms which can't compete with American corn prices. (Those of you who object to Mexican farm labor should throw your lot in with the anti-subsidy crowd: it's just the subsidies which enable Americans to pay migrant workers $4 an hour while just across the boarder no farmer can afford to hire at $1 an hour. It's not something magic in the soil which makes American farms magically 4 times as efficient at turning labor into food - its the subsidies.)

In conclusion, corn subsidies do enormous harm. While I haven't supported every anti-subsidy argument in this post, I've shown that without corn subsidies you'd have the equivalent weight loss of 10 lbs per year. (I suspect many Americans diet more because of their HFCS-related weight gain - imagine if you got an extra 10 lbs of "free" fat per year! Mmmm... what I'd do!)

It's going to be a tough fight against the food industry, but there are lots of good reasons to abandon our current destructive corn-driven Leviathan. Let's ditch the subsidies and let 'em howl.

Local Produce vs. International Peace

Greetings, Macaroni Munchers.

A lot of my friends are concerned about buying food from too far away, in the interests of both helping out the local economy and of reducing fossil fuel consumption. It's a scary thought about how much our food supply depends on non-renewable resources like transportation fuel, and it's appealing to have the visceral connection to what you eat that you can get only from being able to visit the place where your food grows.

Agriculture and the Developing World

The unfortunate consequence of favoring domestic produce, however, is that you deprive the developing world of the much-needed foreign exchange which comes from agricultural exports. In fact, in non-industrialized areas of the third world, pretty much the only thing they produce that we consume is food.

A typical Nicaraguan farm worker earns about $.25 an hour (a quarter the minimum wage of neighboring Costa Rica). The cost of living there may be quite low, but still I'm disgusted by the fact that they could pick coffee for 8 hours and not earn enough money for a singe espresso shot in an American café.

By insisting on buying domestic food, we're just driving developing-world wages down farther. There are plenty of options for Americans: they don't all need agricultural work to stave off extreme poverty. Giving meaningful work to developing nations promotes the sense of coöperation which leads to good feelings and peace.

Dependence on developing nations for food can also lead to peace-making policy. You're less likely to invade another country if you need the food they produce to survive.

Aside: I'm being overly-dramatic. Americans consume on average 3790 calories per day (although some of that is spoilage), so losing even a third of food imports wouldn't spell widespread famine. At the same time, you're less likely to go to war with an entrenched trading partner; the European Union may have ushered in an age of post-historicism, now that individual countries are so economically entwined that it would be sillier than ever to go to war.

Fuel Costs by Sea and Land

Trade and peace aside, many of my friends want to consume as little fossil fuel as possible in getting their food delivered, so they're careful to buy only from locally-grown produce. However, raw distance-from-home is a poor tracker of fuel consumed, since freight by sea is so much more efficient than by land. Let's figure out just how much more efficient it is to ship a container one mile by sea than by land.

By land, a typical mileage rating for a semi truck carrying a 53-foot trailer is about 6 miles per gallon. Page 5 of this document has all of the relevant information: an ultra-sized container ship traveling at 22.5 knots burns 180 tonnes of fuel per day, and carries 10 000 twenty foot-equivalent units of cargo. After a little math, we find the ship transports the same 53-ft container at 44 miles per gallon.

A ship coming to the United States from Chile burns about the same amount of fuel per container as a semi truck traveling about 700 miles, and if people drive 8 miles to the grocery store to buy 50 lbs of groceries in a car rated at 30 miles per gallon, they burn as much fuel per grocery item as that container ship from Chile.

Conclusions

Before jumping on the "local food" bandwagon, please consider the impact of shunning the developing world. Also, consider biking, busing or walking to the grocery store when possible if you're really interested in reducing fossil fuel consumption.

Bon Appetit!

Warning Labels on Soda Pt 2: the Real Risk

Greetings, fellow nerds.

Last post, I ridiculed the warnings on the side of 2 liter soda bottles; in-depth studies did not find a single instance of them causing any serious eye injury. Today I'm going to estimate your health risks once the bottle is open.

If the soda you bought wasn't diet, then it's loaded with one of American nutritionists' worst nightmares: high fructose corn syrup (HFCS). HFCS is the most common caloric sweetener in soft drinks in the United States, in part because agricultural corn subsidies make corn plentiful and cheap.

HFCS: Empty Calories Without Filling You Up

It's a real shame that corn was chosen as the US's crutch crop, because HFCS happens to be not just pure sugar, but it's a kind of stealth sugar which doesn't make you feel less hungry. HFCS calories then don't displace other calories in your diet.

In the year 2000, a study was undertaken where human subjects were made to consume 450-calorie portions of either soda or jelly beans on a daily basis. Whereas the jelly bean-eating group ate fewer calories to compensate for the fact that they had to eat jelly beans (if only I were a five-year-old when this study started - talk about your dream job!), the soda-drinking group's appetite did not decrease at all - in fact drinking soda may have increased the subjects' appetite (although this increase was not statistically-significant).

The study I mentioned is not alone: research has shown that HFCS may be a serious culprit in the epidemic of obesity since HFCS can be directly converted to fat easily, and a 2006 summary of recent research has shown sugar-sweetened beverages to be dangerous in cross-sectional, prospective and experimental studies.

There is a mountain of scientific evidence that drinking HFCS in soda is bad for you. There's even been talk of putting a Surgeon General's warning on soda cans, since they are so unhealthy. How unhealthy are they? Here's my estimate.

Health Impact of the HFCS in Soda

If you drink that 2L bottle of non-diet soda, you're adding its whole 1000 calories to your diet, since HFCS doesn't fill you up. According to an earlier estimation of mine, eating 800 extra calories has a 94 in a million chance of killing you, which makes the risk associated with consuming a single soda bottle is about 118 in a million: there's a greater than 1 in 10,000 chance that drinking a 2L bottle of non-diet soda will kill you in the following 15 years.

Conclusion

Drinking the soda in a 2L bottle is at least one million times more risky than opening the bottle. Yet, the warning label on the bottle is for the latter, not the former. I wonder if maybe the label is there to try to assure us that the most dangerous part of enjoying the soda is opening it, lulling us into a false sense of security. In any case, once again we see that Americans are concerned with the wrong risks. Let's stop fear-mongering about things which won't hurt us and try to educate ourselves about things that might.

PS I've added drinking 2L of HFCS soda to the ever-expanding risk list wiki. So far, it's the first activity to warrant a yellow alert.

EDIT: I've added the life expectancy decrease (LED) and equivalent driving distance (EDD) metrics to this post. See this post for an introduction to the LED and EDD.

If consuming a 2L bottle of non-diet soda has a 118 in a million chance of killing you within 15 years, then its EDD is (1 billion miles / 14.6 * 118 / 1 million) = over 8,000 miles. So, it's safer to drive for 8000 miles than to consume a 2L bottle of non-diet soda.

The LED is (80 years * 118 / 1 million) = about 3 and a half days: enough to give you pause.

Under Pressure: Attack of the Killer Soda Pop

Greetings, fellow nerds.

If you consume soft drinks in the United States, chances are that you've noticed that this warning has begun to appear on two liter soda bottles. When I first saw it, I could hardly believe my eyes. I find it hard to imagine what possible circumstances could conspire to cause the cap to blow off with enough force to do bodily harm. So why the warning label? Does it really help, or is it just the brainchild of a misdirected torte lawyer?

I'm going to argue that the real dangers of soda come from drinking it, not opening the lid. I'm going to expose how skewed our senses of risk and responsibility are by showing that the high fructose corn syrup in soda does far more damage than its allegedly explosive top. This post will cover the risks of getting blinded by a rocketing soda pop top, while the next one will look into the health consequences of drinking that same soda.

The Letter Never Sent

When I set out to uncover the statistics behind the warning labels on soft drink bottles, I had imagined having to write to a representative of some bottling authority with a request for statistics on eye injury resulting from opening plastic bottles. I'd say my friends and I are casually interested in why these warning labels were deemed necessary, and ask for the reasoning behind the warnings.

I was kind of looking forward to composing the letter. Setting the right tone would be key: I'd have to come across as earnest while acknowledging the whimsical nature of my request. Usually, public relations people at corporations give you the benefit of the doubt and respond in good faith. However, it turns out injury statistics from soda bottles are well-known and published, so writing is unnecessary. I might still write that letter; if you'd like me to carry through with this plan let me know in a comment.

The Answer's Before Our Eyes

I'm not planning on writing the above letter because the British Journal of Optometry has already answered my question. In this publication (.pdf warning), titled “Serious eye injuries caused by bottles containing carbonated drinks”, they say “plastic and metal cans pose little danger: we found no related injury among the 12 889 cases.” Their database held combined data from the US, Hungarian and Mexican eye injuries from 1982 – 2002 (although it didn't have data for all countries and all years).

The paper's authors (F Kuhn, V Mester, R Morris and J Dalma) found not one instance of a soda pop bottle causing an eye injury in any of the countries in any year. It would be a stretch to say that absolutely no eye injuries happened because of pop bottles during the 1982-1999 period in the States (2000-2002 US data not published in Kuhn et al.) since the database of eye injuries used (USEIR) collects information of only serious eye damage, and not all states of the US contribute data to USEIR yet. Still, the fact that Kuhn et al. found not one case of plastic bottles causing eye damage over a 20 year span is suggestive that they're pretty harmless. If you know of someone who has been injured by a plastic bottle top, please leave me a reply about it.

Incidentally, champagne is not so benign. Kuhn. Et al. mention 43 cases of severe eye injury from sparkling wine corks to the face; the majority of these (37) were in Hungary. The remaining 6 wine cork injuries happened to Americans. If we assume the USEIR reflects only about half of all eye injuries, that's still less than 1 serious American injury per year. (Aside: Does anybody know what Hungarians put in their hooch that makes it so explosive? Kuhn et al. are baffled too.)

I'm Armed and Carbonated

Because I'm a physical sciences nerd, I'm going to figure out how dangerous pop bottle caps could be under ideal firing conditions. Typical soft drinks are pressurized to about 300 kPa. If the surface area of the cap is 3 square cm, the cap is under about 90 Newtons of force, or about 20 pounds. If we assume that some manufacturing error resulted in the cap suddenly becoming loose after a vigorous shaking of the soda at room temperature, this 90 Newtons would act on the cap for as long as the cap blocks the exit path of the gas: about 2 cm. If that 90 Newtons accelerates the cap for 2 cm, the energy transferred to the cap would be only 1.8 Joules. Most accidental cap accidents would be under less-than-ideal launch conditions, so I would be surprised if caps blew off with more than 1 Joule of energy.

How much is 1.8 Joules? About the same amount of energy as a snapped rubber band (one with a spring constant of about 250 N/m), if you stretch it three or four inches. That might sting if it hit you in the eye, but it's not likely to do permanent damage even with a direct hit. It probably wouldn't be too hard to get pop bottles approved as projectile toys for kids old enough not to try to swallow the cap.

In summary, my analysis suggests there isn't enough punch in a plastic bottle cap to do serious harm, and the lack of any evidence of eye injuries backs up my case. From here on in, I'm going to assume that the risk of serious injury from pop bottle tops to consumers (forewarned or no) is 0. Of course it isn't exactly 0, but the Kuhn et al. study covered about 5 billion person-years of exposure to pop bottle tops and didn't find a single serious injury, suggesting an upper bound on the injury rate of about 1 per 10 billion: close enough to 0 not to matter.

Time lost to the warning label

Even though an in-depth study failed to find even one instance of a plastic bottle cap damaging anybody's eye, one might think that it's better to abide by the precautionary principal, that is to warn people of the pressure danger in opening their soda on the off chance that we might prevent even one eye injury. I can imagine the person making the decision to put warnings on all plastic bottles would have a warm, fuzzy feeling if they saved the vision of even one child.

I disagree with the precautionary principal for two reasons. First, the cost of having warning labels is not zero: the precious seconds of our lives we waste worrying about inflated risks add up. Second, ubiquitous, petty, self-important warning labels can inure the public to warnings on genuine risks.

Time Lost Reading Gratuitous Fear-Mongering Messages

How many lifetimes have been wasted reading this warning message? Let's assume that, on average, every American reads this warning once per year. (I don't know if the rest of the world has adopted the warning label yet. Let's hope the insanity has been confined to the Home of the Mega Lawsuit.) If it takes about 10 precious seconds of your life to read through the text, that means that nationwide, about 95 years of life are wasted every year we insist of putting these gratuitous warnings on soda bottles. Equivalently, as you read this, you can expect 95 Americans are busy reading through the above text about how their life is potentially threatened by the intense pressure of the liquid refreshment in their hands.

Think of the good which could be done with those 95 person-years. Movies, novels and poetry written, walks in the park, vacations; all of these and more might have been accomplished if it were not for these unnecessary, attention-whoring portents of soda pop doom. There are some who balk at doing moral algebra. I think that 95 years of vision wasted by eye injury is in principal equivalent to 95 years of vision wasted by reading a warning label.

Since the net effect of the warnings is to decrease the visual lifetime of the consumer, I propose that the soda bottle companies stop printing the warnings. I also propose that we allow companies complete immunity from lawsuits arising from activities whose associated risk is so small that to post warning labels does more net harm than good.

Warnings, Warnings Everywhere...

... nor anyone to think. Perhaps the most damaging consequence of posting warnings on soda pop bottles is that we end up reflexively ignoring them. I hesitate to read every warning label I see (in truth, I didn't even notice this one below until this minute when I started looking for warning labels).

What's on the bottom of my keyboard? Is there a risk of electric shock? Perhaps deadly chemicals leak up from between the keys every midnight. How would I know? I plugged in my keyboard, it worked, and I'm happy. There's no way I'm going to pursue every last nagging, ass-covering warning I see out there, and that means I'll ignore warning signs when there are real dangers too.

I think we should standardize a color-coded warning label system, where different risk orders of magnitude have different colors. You could ignore anything less than a yellow then, unless you were exposed to the risk all the time. Manufacturers would be immune to lawsuits over correctly-labeled risks, and would be made liable for time lost if they grossly overstate the risk. I've started a list of color-coded risks - check out my wiki and add to it if you feel so inclined.

Conclusions

Gratuitous warning labels (such as the one on pop bottles) make us worry about the wrong things. There are genuine risks out there, but the system we have for making people aware of them is broken. We need to push through laws that protect companies from one-off lawsuits caused by the failure to alert customers of excessively-small risks, and then maybe we can talk about demanding that risk labels be removed when the opportunity costs or reading them outweigh the benefit they do.

EDIT: I'm adding information of the life expectancy decrease (LED) and equivalent driving distance (EDD) for opening a bottle of soda. See this post for an introduction to the LED and EDD.

If Americans open roughly 100 soda bottles per year, and if the annual risk of getting an eye injury from opening a soda bottle is less than 1 in 10 billion, the risk of opening each bottle is less than 1 in a trillion. That means that even if we were to assume any serious injury from a soda bottle were fatal, you life expectancy would decrease from opening a soda bottle by only 2.5 milliseconds (80 years - a typical lifespan / 1 trillion). Opening a soda bottle therefore has an LED of 2.5 milliseconds or less.

The EDD is computed by the fact that 14.6 driving fatalities occur every billion miles. The distance you'd have to drive to incur the same risk as opening a soda bottle is therefore 1 billion miles / 14.6 / 1 trillion; the EDD is less than 4.5 inches; so driving more than the length of a pickle is more risky than opening a soda bottle, once again with the ridiculous assumption that all bottle top eye injuries would be fatal.

Mad about BSE

Greetings, fellow nerds.

This will be just a quick post about the relative risks between the "mad" and the "cow" in mad cow disease. In truth, the danger "tainted beef" poses to us is so small that as a consumer, you should forget about mad cow disease entirely: it's a waste of neurons. I'd even feel guilty making you read this post if it weren't for the fact that it exposes the sensationalism behind mad cow disease reporting.

Assessing Mad Cow Lethality

Mad cow disease in cows is called bovine spongiform encephalopathy (BSE), and to date there have been at least 188515 reported cases of it worldwide. Common sense suggests that there are a whole lot of unreported cases too, considering the incentives farmers have to keep things quiet. The disease humans contract by eating infected cows is called variant Creutzfeldt-Jakob disease (vCJD), and there have been a total of 170 confirmed cases worldwide. This number is probably not exaggerated (in fact the false positive rate for vCJD might be rather high), so you might think of 170/188515 (or about 900 per million) as an upper bound on the chances of contracting vCJD from eating an entire mad cow. However, probably not all of the 188515 cows were consumed in their entirety, which means that 900 per million might be a good ballpark figure as to the actual transmission rate from eating a whole cow.

If there are roughly 250 lbs of meat per cow, and if a typical beef meal has a quarter pound of meat, the odds of catching vCJD from a single meal of infected beef are 900 in a billion. When you consider that in the time period the 188515 cows were detected, the UK (the country hardest-hit by BSE) produced about 100 million cows, the risk of getting vCJD from eating one randomly-chosen UK beef meal is about 2 in a billion.

No Consensus among Academics

Why aren't I just reporting what the medical journals say about BSE to vCJD transmission rates? Because these estimates are all over the place. This study in the journal "Risk Analysis" by Eric Grist shows that there's nothing like consensus regarding the risk of a human contracting vCJD from eating an infected meal: published transmission rates vary from 0.9 in a billion to 7 in a thousand (c.f. my estimate of 900 per billion based on case numbers). The "Risk Analysis" article continues on to point out that the 7 in a thousand measure is obviously inconsistent with observed vCJD infection rates. (Thank you, Dr. Grist!) Perhaps even researchers are prone to sensationalism, especially if the said sensationalism might result in extra funding.

New Risk Metrics

We need better units for analyzing risks. It's hard to grok these raw numbers without an everyday context, so I'm going to introduce two new metrics:

1. Life Expectancy Decrease (LED)
   
2. Equivalent Driving Distance (EDD)
   

The LED measures the expectation of the decrease in life expectancy based on taking the risk once, assuming an 80 year lifespan. So for example, the LED from eating a meal with UK beef at the height of the mad cow scare is (80 years * 2 per billion) = 5 seconds. Compare that to the LED associated with the extra calories in your fast food meal: (80 years * 94 per million) = 2.7 days. The extra risk of vCJD is insignificant next to the threat of the extra calories involved with taking a big bite of beef.

Driving cars is a risky activity that most of us have come to terms with. Driving therefore provides an ideal reality check that helps us put new risks in perspective. This DOT report (page 8 of the .pdf) shows that there are about 14.6 vehicular fatalities for every billion miles traveled. The EDD of a new risk is the length of the car trip with the equivalent level of risk. For example, the EDD of the untested UK beef meal is (2 per billion * 1 billion miles / 14.6) = 720 feet; less than one Manhattan city block. Again, if the beef was in a fast food meal, the EDD from the extra calories is over 6400 miles: greater than the radius of the Earth.

Conclusion: Calories Matter More than Prions

If you spent more than 5 seconds worrying about contracting vCJD from beef, even at the height of the mad cow scare in the UK, you've been had. Also, if you think a fast food meal saves time, you should consider the 2.7-day lifespan decrease it brings (unless you're underweight - see my blog entry). It's true that the risk was unknown at the time (so maybe caution was indicated), but I'm getting sick of people worrying about false alarms, especially when there are more pressing issues which aren't getting enough attention.

I'm also disillusioned with the media, although I can see their point. Nobody will buy a paper saying "Get Off Your Butt and Get Healthy," but "New Plague Risk Sweeps the Nation: Will YOU Die?" has more zing.

As new crises come up in the news, I'm going to try to keep up with the LED and EDD metrics for them. With any luck, they'll catch on as popular reality checks for how risky a new terror actually is.

Death match: Big Macs vs. Unprotected Sex

Greetings, fellow nerds.

My Spanish teacher in Costa Rica (Carlos P. - the P. stands for a word which happens to be the foulest word in the Portuguese language, which was entertaining to the Brazilian immigration officials - that's entirely another story though) asked me why Americans are fanatical about staying AIDS-free, but don't give a pair of dingo's kidneys if they die of being too fat. Carlos, the more I think about it, the more it sounds like you're on to something, and I'm going to follow up your comment with a numerical analysis: today we're going to weigh the risk of HIV contracted from having unprotected sex against the increased risk of dying from obesity by eating one Big Mac™.

HIV risk from unprotected sex: what are the numbers?

First off, let's quantify the HIV risk of having sex with an American chosen at random. The CDC estimates the percentage of HIV-positive US residents to be 0.4% (as of 2003). That's already a low number, but to asses the risk of catching HIV from unprotected sex we have to multiply by the transmission rate: that is, given that you have unprotected sex with somebody who's HIV-positive, what are your chances of getting it?

What is this transmission rate? Take a guess. Now decrease it by a factor of 10. If your guess was like mine, you'd still be way above the truth. I don't know if it's general squeamishness or over-zealous sex ed teachers, but the risk of HIV transmission between otherwise-healthy people is between 5 and 50 cases per 10,000 acts, depending on exactly what kind of (more-than-just-oral) unprotected sex you're having (Wikipedia link + original article). That means if you and your (randomly-selected vis. HIV status) American partner are healthy, you have between a 2 in a million and a 20 in a million chance of contracting AIDS from unprotected sex.

Let's put that into perspective. If you live to be 80, you'll have lived 29 200 days. What are the chances (everything else being equal) that today your number's up? That would be 1 / 29200 = 34 in a million, almost twice the HIV risk associated with receptive anal intercourse from a randomly-chosen American male.

My heart goes out to people who have contracted HIV from unprotected sex. I'm sure they have been demonized for being so careless as to indulge in this (so-called) risky behavior. Let's find out just how risky their behavior really was, in terms of Big Mac™ eating.

What's the Lethal Dosage of Big Macs™?

First of all, I don't want to single out Big Macs™, McDonald's™, or even just the fast food industry as unique bringers of ill-health. The Big Mac™ is however a nearly-ubiquitous unit of culinary over-indulgence; let it here symbolize any overly-calorific meal.

There's a good chance that fast food-related factors other than too many calories cause health problems. Films such as "Super Size Me" suggest that high concentrations of fast food can kill - suppose Morgan Spurlock had spent 100 days on the McDonald's™-food-only diet and found that to be lethal. Then we could estimate the risk of eating a Big Mac™ to be 1 in 300 (for 300 meals). That's a risk of more than 3000 per million meals, or between 150 and 1500 times the risk of contracting HIV from unprotected sex. When spread out over many years, the lethality of Big Macs™ can't be that high, so let's get a low-ball estimate of the risk on Big Mac™ poses by its calories alone.

Weight Gain from a Big Mac™ Meal

Surprisingly, if you eat a Big Mac™ and nothing else as a meal, you get about the right number of calories. Assuming that you should be eating 1800 calories a day, the Big Mac™'s 600-calorie payload doesn't sound so bad. It's the side dishes which add the real risk. Full meals at fast food restaurants can have as many as 1825 calories - 1025 too many for an 1800 calorie-a-day diet. For now, let's assume the typical fast food meal has 800 superfluous calories which will be carried around by the diner essentially forever. (I'm not sure if eating too much has a net positive or negative effect on one's metabolism: if you're heavy you might decide to drive instead of walk so much that it counteracts the need to fuel a bigger body.) That 800 extra calories per fast food meal translates to just under a quarter pound of extra body weight; let's see what that does for your health.

Mortality Increase per Big Mac™

I could give you a laundry list of symptoms you could get by being overweight, but instead I'll just boil it down to a number: how much does your mortality rate increase if you have that extra quarter pound on your paunch? According to this JAMA article, in 2000, 111 909 excess deaths were caused by obesity among the 23.3% of Americans who were obese or extremely obese (defined as having a BMI above 30). In 2000 there were 281,421,906 Americans total, which means that 0.17% of obese people died that year from being obese. That's just for the year though - since HIV can let you live for 15 years or more, the risk of dying from obesity in the same span of time you'd expect as from an HIV infection is 2.5%, or 1 in 40.

The last factor to consider is how likely it is for an extra quarter pound to push you into the danger zone. (Aside: in reality, there probably isn't any sharp divide between safe and risky BMIs, but we can still get a feel for the effect size of being obese by this discretization.) From the same study, 33.8% of Americans have a BMI from 25 to 30. Assuming an even distribution of BMIs in the 25-30 range and an average height of 5'10", about 0.8% of people with a BMI between 25 and 30 would be tipped into the BMI > 30 class from that one extra fast food meal. If we assume the risk of already-obese people is at least as great as the risk to overweight people, that means that for 47.1% of the American population, eating one Big Mac™ has a .8% chance of increasing your mortality risk over the next 15 years by 2.5%. Multiplying probabilities, the total risk of that Big Mac™ killing you within 15 years (again, assuming you're a randomly-chosen American) is at least 94 in a million, or between about 5 and 50 times the HIV risk of unprotected sex! That's an average too; if you're overweight, Big Macs™ are at least twice as deadly.

Caveats

There are a few weak points in my argument; let me list them. Here are some factors which may make HIV more dangerous than I let on.

1. People who have more unprotected sex with multiple partners tend to have partners with higher HIV risk too.
2. Other STDs can increase the rate of transmission of HIV by increasing the volume of fluids exchanged.

Additionally, I didn't factor in that being underweight can be risky too; in other words, Big Macs™ could be a benefit to skinny people.

However, my final analysis also didn't take into account the fact that fast food is nutritionally poor, an additional danger I have not accounted for. Moreover, I only counted the obesity risk over 15 years, while the risk in fact continues for as long as you are obese.

Conclusion: Big Macs™ are More Deadly than Unprotected Sex in America.

It would be incorrect to state that every Big Mac™ consumed poses more risk of death than every act of unprotected sex. It also would be wrong to claim that the HIV/AIDS epidemic has been totally eclipsed by a wave of obesity; factor #1 under Caveats is too big to ignore in an epidemiological context. However, given my reasonable assumptions, I find that on average Big Macs™ are 5 to 50 times more deadly than unprotected sex with a randomly-chosen American. Carlos P., your intuition was right.

Here's the take-home message:

1. HIV is harder to contract than you might think.
2. Too much food can kill you.
3. We should worry more about our diets, and perhaps less about disease.
4. If you're like me, you probably worry too much about the wrong things.
   

To address #4, I've started a wiki to keep track of the risks around us. Help me complete and update it; then maybe we can keep a sense of perspective when it comes to banal topics like Big Macs™ and ominous-sounding plagues like HIV/AIDS.