The headline went splashing though social media last week: World Health Organization Says Bacon As Deadly As Plutonium.
It sounds awful. Did they really say that? Not exactly. The report does classify processed meat as carcinogenic in their highest-danger classification, Group 1, along with asbestos and plutonium. But it's not a scale of deadliness-per-unit volume, only of how well-linked a substance is to causing cancer. It's confusing and has prompted articles trying to explain what it means and generally succeeding.
Here's the thing to know: "The dose makes the poison." Paracelsus wrote that in 1538 -- and he was right. A cross-grained iconoclast after my own heart, he valued practical experience and rigorous experiment as pathways to accurate knowledge. Plutonium has an LD50 -- the amount that will kill half those who ingest it it -- of 0.00032 grams per kilogram of body weight; if bacon were composed of pure sodium nitrate (it's not), its LD50 would be
0.18 g/kg (source).
I'm using toxicity as a crude proxy for carcinogenic qualities; this is fast, sloppy and inaccurate, but it lets us compare orders of magnitude easily. A speck of plutonium with your breakfast is a very big problem, while a speck of bacon is not. It appears there's a threshold level for processed meat: eating too much bacon is indeed bad; eating a little bacon, you can treat as a manageable risk, the same as driving a car or hanging out with your friends and family. (Not everyone agrees how much bacon is too much or how little is just right.)
If you're having bacon bits for breakfast in place of oatmeal and washing them down with hot bacon fat, you're in trouble. If you're averaging one strip of bacon or less in the morning, you take far higher risks every day in the shower.
(Details for geeks: most risky activities have a linear relationship between increasing frequency or volume and increasing risk -- except at the very low end, where things get nonlinear: maybe even a tiny dab will do you in; maybe mitigating strategies work up to a point [sunscreen/hat]; maybe the risk goes to zero ahead of the volume, or the slope even reverses [water intake, for example, where too much can eventually be as deadly as too little]. Understanding these low-end-of-the-curve behaviors is essential to managing risk intelligently.)
Since it was brought up in the "highest-danger classification, Group 1, along with asbestos and plutonium" line, it is probably worth pointing out that asbestos does not necessarily adhere to the Paracelsus "dose makes the poison" rule.
ReplyDeleteSure, there is a dose-response relationship, in that a lot more high-exposure people get mesothelioma in comparison to low exposure folks, but there are enough studies showing that risk of mesothelioma is increased even at low levels of asbestos exposure that there is lore that "one (lucky) fiber can kill you".
(beware of purported 'fact checks' that will rephrase that as "one fiber will kill you".)
Note that I'm generally quite critical when legislation follows the epidemiological theory that there is no lower limit to a risk.
And sorry for the digression -- I was recently suffering from a really severe cold where I (correctly) surmised that nasal irrigation would help ease my symptoms and allow sleep, but we'd thrown away our neti-pot for fear of Naegleria fowleri . We only ever fill our electric-kettle with water filtered through a countertop ion-exchange filter that meets CDC recommendations for providing water for nasal-irrigation saline solution, but I had to evaluate if I've really adhered to suitably sterile procedures when changing the cartridges, as this is another case where lore would have a single amoeba leading to brain-eating horror.
Plutonium Bacon would be a good band name.
ReplyDeletePlutonium Bacon's first album, "Brain Eating Horror" will be a smash hit.
ReplyDeleteI'm going to assume that a little bacon is like a little ionizing radiation, i.e., it's good for you. I'm also assuming the hormesis idea is correct.
ReplyDeleteMaybe I should switch to plutonium bacon; my morning bowl of depleted uranium oatmeal leaves me feeling bloated.
ReplyDelete