Though age is the big risk factor for Alzheimer's disease, an analysis of Swedish twins has led some to believe that half of individual differences in Alzheimer's disease risk may be environmental.

Chemists, toxicologists, and biologists note that we would have gone extinct long ago if our bodies had not been able to absorb, metabolize, ignore, or excrete trace substances but since 2005, when a new salvo against public trust in the modern world was opened, there has been talk that an "exposome" can cause all kinds of diseases.

Everything you are exposed to, your environment, can cause cancer, if you just look hard enough. Organic food? Sure, if conventional food trade groups were as unethical as Organic Consumers Association. Natural gas? Why not? Street lights, windmills, 5G cell service, wood paneling, if you really want to find a correlation between a product and a disease risk you can, when all it takes is rows of environmental stuff and then columns of diseases and finding what you can link to whom.

Our "exposome" is so broad, it's everything we contact in our lives, that it's difficult to dispute any correlation. Like autism or claims of endocrine disruption related to vaccines, the net for possible inputs is so big if you can detect anything you can link it to anything. And some do. More than average light, invisible car exhaust, ambient street noise, they've all been linked to birth defects. And now Alzheimer's has been statistically linked to the environment, without ever doing an examination of people who have the disease.

Give me a large enough matrix and I am guaranteed to find a link to a disease. We can even show coin flips are not random with statistical significance, if we don't care about replication. This image from Environmental Health Perspectives (DOI:10.1289/EHP2862), the official journal of Scaremongering, Inc.

Alzheimer's is so poorly misunderstood it is open season for speculation and even quack remedies like microbiome supplements. The authors of the paper linking Alzheimer's to our exposome say their work is "theoretical" but they are using that term in the populist sense. There is no theoretical foundation to anything in this, there is only genes and being poor and a statistical correlation to a greater risk of Alzheimer's.

There is nothing wrong with inference, of course, when Darwin wrote "I think" with his tree he didn't have Mendelian genetics, but his inference was so compelling it set off a cultural and scientific firestorm and we got Modern Synthesis out of it. Exposome Alzheimer's is instead 'god of the gaps' thinking, filling unknowns with a crazy idea that can be as good as any other, like that Alzheimer's may be caused by living in a city apartment building. That's sociology, not science.

The first stretch is the belief that two gene families "cause" Alzheimer's even though we don't even know really what the disease is. Their reductionism says familial Alzheimer's genes will cause someone who inherits those genes to develop Alzheimer's while gene variants like apolipoprotein E4 (APOE4) are linked to an increased chance of getting it if there are more copies. Since fewer people with APOE4 reach age 100 without developing Alzheimer's they push the exposome into that gap.

Did glyphosate cause Alzheimer's? How about formaldehyde? Climate change?

And they do fill the gap with their belief, by taking the age of onset and linking it to living in cities, especially poorer neighborhoods. They have to make sure to note poorer neighborhoods and not just cities because otherwise living in crowded Manhattan is a big confounder.

But that is completely arbitrary because it requires you to believe, without any evidence, that the exposome is causing Alzheimer's but wealth is preventing it. The city exposome is the city exposome, all the money in the world did not prevent the Black Plague from getting you and neither will it prevent you from ambient trace particulate matter or street lights, if that is what we are to believe causes Alzheimer's.

Were this exposome claim to catch on - here's hoping Moms Across America doesn't get Eric Lipton of the New York Times to claim it's related to vaccines - there is no limit to what could be linked this way. It requires no evidence because it is Magic Rock Thinking.

Here is an example of Magic Rock Thinking via that esteemed science outlet "The Simpsons", season 7, episode 23; "Much Apu About Nothing."(1)

HOMER: Well, there's not a bear in sight. The Bear Patrol must be working like a charm.
LISA: That's specious reasoning, Dad.
HOMER: Thank you, honey.
LISA: By your logic I could claim that this rock keeps tigers away.
HOMER: Oh, how does it work?
LISA: It doesn't work. It's a stupid rock.
HOMER: Uh-huh.
LISA: But I don't see any tigers around here, do you?
HOMER: Lisa, I want to buy your rock.

This article could lead people to the same conclusion. Want to avoid Alzheimer's? Don't be poor. Don't live in cities. I you didn't get Alzheimer's this magic rock speculation about the exposome saved you but even if you do get Alzheimer's, well, a better exposome only reduces risk.

You can't lose with magic rocks.

Like organic food trade groups demonizing conventional food (meaning poor people who can't afford organic buy fewer fresh vegetables at all) this could lead to dangerous determinism. Why not smoke if you can hear street noise and can't see the stars and therefore your fate is sealed 10 years before rich people with the same genes?

The entire world causes Alzheimers?

The exposome can withstand any of these criticisms because there is a dab of science and a whole lot of mysticism. Your gene variants can be impacted by sports participation, your individual biome (right there we are out of the science world), how much you exercise, other illnesses you have, obesity, hormones - basically, all of human existence is a risk factor. Smoking can cause many diseases, but Alzheimer's? If so, why hasn't Alzheimer's plummeted as smoking did?

The exposome is the endocrine disruption hype of the Bush era. Neither has ever been shown to be right but they are so broad and non-secific they can never be shown wrong either.

There is always some risk that talking about speculative claims gives them credence but we started talking about California vaccine denial long before it created a national epidemic and if journalists in mainstream media had done the same thing, the problem might never have happened. The last thing family members of Alzheimer's patients need is lawyers mobilizing fear and doubt about air quality or street lamps to line their coffers.