Tuesday, September 14, 2010

Getcher antioxidants today -- at McDonald's!

Robert Waldmann complains that McD's gets a bad rap for its food being "filled with preservatives":
I think that BHA and BHT are good for you.

The weird thing is that health food enthusiasts are convinced of two things -- that anti-oxidants are healthy and that preservatives are unhealthy. The only problem is that "anti-oxidant" and "preservative" are synonyms.

This is not (quite) a logical inconsistency. Their view is that natural preservatives are healthy and that synthetic anti-oxidants are unhealthy. There is essentially no evidence supporting this hypothesis and people have been looking for such evidence for decades. * * *

To get technical, preservatives are anti-oxidants and oxidative stress (roughly rusting) is allegedly implicated in cancer and cardio-vascular disease. I note that there was a dramatic increase in US life expectancy in the 70s (similar to the increase in the 40s following the introduction of penicillin). This was due to reduced incidence of heart attacks. It was ascribed to improved diet and increased exercize. Sure mac, that's why we are so much thinner than we used to be.

Now continuing improvement can be partly explained by statins (one can be overweight, eat lots of saturated fat, never exercize and have low LDL cholesterol these days -- that's my plan). Also some by bypass surgery and shunts and stuff. This is mostly post 70s. There is a huge mystery in the data which can be explained if it is noted that anti-oxidants reduce arterio-schlerosis in model systems (over-fed rats).

In any case, the claim that anti-oxidants prevent arterioschlerosis is absolutely totally very respectable and BHA and BHT are anti-oxidants. There is a fairly large literature asserting that this or that food contains anti-oxidants. In each case which I checked, the anti-oxidant was compared to BHA or BHT (or both).

So why are people so deeply convinced that BHA and BHT are bad for our health ? One reason is that extremely large doses cause cancer of the fore-stomach in mice and rats.

This result was part of the evidence which convinced people (including the guy who taught me organic chemistry) that organic chemistry was a menace, because many many synthetic organic chemicals are carcinogenic. In 1979, he predicted a big increase in cancer in the 80s roughly 20 years after they began flowing into our diet (20 year lag from aggregate cigarette smoking and lung cancer). That didn't happen -- aggregate cancer incidence is almost completely explained by age (to the fifth) and cigarette smoking. My view is that many compounds which are carcinogenic in huge doses are safe in small doses and in other cases the carcinogenisis depends on the fifth power of the dose which amounts to pretty much the same thing. Also I am not a mouse and don't have a fore-stomach.
Now if only the value meal came with a beer. (H/t Drum.)

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