Like our lack of fur, acne remains an evolutionary mystery to me.
Do other furless mammals get acne? Like elephants or whales? Or even chimps; their faces don’t have fur. If so, everyone’s keeping it a secret–I’ve never even seen an add for bonobo anti-acne cream, and with bonobos’ social lives, you know they’d want it. :)
So far, Google has returned no reports of elephants or whales with acne.
Now, a few skin blemishes here and there are not terribly interesting or mysterious. The weird thing about acne (IMO) is that it pops up at puberty*, and appears to have a genetic component.
Considering that kids with acne tend to feel rather self-conscious about it, I think it reasonable to assume that people with more severe acne have more difficulty with dating than people without. (Remember, some people have acne well into their 30s or beyond.)
Wouldn’t the non-acne people quickly out-compete the acne-people, resulting in less acne among humans? (Okay, now I really want to know if someone has done a study on whether people with more acne have fewer children.) Since acne is extremely common and shows up right as humans reach puberty, this seems like a pretty easy thing to study/find an effect if there is any.
Anyway, I totally remember a reference to acne in Dr. Price’s Nutrition and Physical Degeneration, (one of my favorite books ever,) but can’t find it now. Perhaps I am confusing it with Nutrition and Western Disease or a book with a similar title. At any rate, I recall a picture of a young woman’s back with a caption to the effect that none of the people in this tropical local had acne, which the author could tell rather well since this was one of those tropical locals where people typically walk around with rather little clothing.
The Wikipedia has this to say about the international incidence of acne:
“Rates appear to be lower in rural societies. While some find it affects people of all ethnic groups, it may not occur in the non-Westernized people of Papua New Guinea and Paraguay.
Acne affects 40 to 50 million people in the United States (16%) and approximately 3 to 5 million in Australia (23%). In the United States, acne tends to be more severe in Caucasians than people of African descent.”
I consider these more “hints” than “conclusive proof of anything.”
Back when I was researching hookworms, I ran across these bits:
“The [Hygiene Hypothesis] was first proposed by David P. Strachan who noted that hay fever and eczema were less common in children who belonged to large families. Since then, studies have noted the effect of gastrointestinal worms on the development of allergies in the developing world. For example, a study in Gambia found that eradication of worms in some villages led to increased skin reactions to allergies among children. … [bold mine.]
Moderate hookworm infections have been demonstrated to have beneficial effects on hosts suffering from diseases linked to overactive immune systems. … Research at the University of Nottingham conducted in Ethiopia observed a small subset of people with hookworm infections were half as likely to experience asthma or hay fever. Potential benefits have also been hypothesized in cases of multiple sclerosis, Crohn’s Disease and diabetes.”
So I got to thinking, if allergies and eczema are auto-immune reactions (I know someone in real life, at least, whose skin cracks to the point of bleeding if they eat certain foods, but is otherwise fine if they don’t eat those foods,) why not acne?
Acne is generally considered a minor problem, so people haven’t necessarily spent a ton of time researching it. Googling “acne autoimmune” gets me some Paleo-Dieter folks talking about curing severe cases with a paleo-variant (they’re trying to sell books, so they didn’t let on the details, but I suspect the details have to do with avoiding refined sugar, milk, and wheat.)
While I tend to caution against over-enthusiastic embrace of a diet one’s ancestors most likely haven’t eaten in thousands or ten thousand years, if some folks are reporting a result, then I’d love to see scientists actually test it and try to confirm or disprove it.
The problem with dietary science is that it is incredibly complicated, full of confounds, and most of the experiments you might think up in your head are completely illegal and impractical.
For example, scientists figured out that Pellagra is caused by nutritional deficiency–rather than an infectious agent–by feeding prisoners an all-corn diet until they started showing signs of gross malnutrition. (For the record, the prisoners joined the program voluntarily. “All the corn you can eat” sounded pretty good for the first few months.) Likewise, there was a program during WWII to study the effects of starvation–on voluntary subjects–and try to figure out the best way to save starving people, started because the Allies knew they would have a lot of very real starvation victims on their hands very soon.
These sorts of human experiments are no longer allowed. What a scientist can do to a human being is pretty tightly controlled, because no one wants to accidentally kill their test subjects and universities and the like don’t like getting sued. Even things like the Milgram Experiments would have trouble getting authorized today.
So most of the time with scientific studies, you’re left with using human analogs, which means rats. And rats don’t digest food the exact same way we do–Europeans and Chinese don’t digest food the exact same way, so don’t expect rats to do it the same way, either. An obvious oversight as a result of relying on animal models is that most animals can synthesize Vitamin C, but humans can’t. This made figuring out this whole Vitamin C thing a lot trickier.
Primates are probably a little closer, digestively, to humans, but people get really squeamish about monkey research, and besides, they eat a pretty different diet than we do, too. Gorillas are basically vegan (I bet they eat small bugs by accident all the time, of course,) and chimps have almost no body fat–this is quite remarkable, actually. Gorillas and orangutans have quite a bit of body fat, “normal” levels by human standards. Hunter-gatherers, agriculturalists, and sedentary butt-sitters like us have different amounts, but they still all have some. But chimps and bonobos have vanishingly little; male chimps and bonobos have almost zero body fat, even after being raised in zoos and fed as much food as they want.
Which means that if you’re trying to study diet, chimps and bonobos are probably pretty crappy human analogs.
(And I bet they’re really expensive to keep, relative to mice or having humans fill out surveys and promise to eat more carbs.)
So you’re left with trying to figure out what people are eating and tinker with it in a non-harmful, non-invasive way. You can’t just get a bunch of orphans and raise them from birth on two different diets and see what happens. You get people to fill out questionnaires about what they eat and then see if they happen to drop dead in the next 40 or 50 years.
And that doesn’t even take into account the fact that “corn” can mean a dozen different things to different people. Someone whose ancestors were indigenous to North and South America may digest corn differently than someone from Europe, Africa, or Asia. Different people cook corn differently–we don’t typically use the traditional method of mixing it with lime (the mineral), which frees up certain nutrients and traditionally protected people from Pellagra. We don’t all eat corn in the same combinations with other foods (look at the interaction between the calcium in milk and Vitamin D for one of the ways which combining foods can complicate matters.) And we aren’t necessarily even cooking the same “corn”. Modern hybrid corns may not digest in exactly the same way as corn people were growing a hundred or two hundred years ago. Small differences are sometimes quite important, as we discovered when we realized the artificially-created trans-fats we’d stuck in our foods to replace saturated fats were causing cancer–our bodies were trying to use these fats like normal fats, but when we stuck them into our cell walls, their wonky shapes (on a chemical level, the differences between different kinds of fats can be mostly understood that they are shaped differently, and trans fats have been artificially modified to have a different shape than they would have otherwise,) fucked up the structure of the cells they were in.
In short, this research is really hard, but I still encourage people to go do it and do it well.
Anyway, back on topic, here’s another quote from the Wikipedia, on the subject of using parasites to treat autoimmunie disorders:
“While it is recognized that there is probably a genetic disposition in certain individuals for the development of autoimmune diseases, the rate of increase in incidence of autoimmune diseases is not a result of genetic changes in humans; the increased rate of autoimmune-related diseases in the industrialized world is occurring in too short a time to be explained in this way. There is evidence that one of the primary reasons for the increase in autoimmune diseases in industrialized nations is the significant change in environmental factors over the last century. …
Genetic research on the interleukin genes (IL genes) shows that helminths [certain kinds of parasites] have been a major selective force on a subset of these human genes. In other words, helminths have shaped the evolution of at least parts of the human immune system, especially the genes responsible for Crohn’s disease, ulcerative colitis, and celiac disease — and provides further evidence that it is the absence of parasites, and in particular helminths, that has likely caused a substantial portion of the increase in incidence of diseases of immune dysregulation and inflammation in industrialized countries in the last century. …
Studies conducted on mice and rat models of colitis, muscular sclerosis, type 1 diabetes, and asthma have shown helminth-infected subjects to display protection from the disease.”
Right, so I’m curious if acne falls into this category, too.