Forgive me if this has been covered already, but I don’t have time to do a search and post this topic, so:
What possible purpose do allergies and allergic reactions serve? Granted, not everything in the world is for the benefit of humans (or other animals who can experience allergies), but this just makes no sense. Allergies do not protect the allergen – it isn’t necessarily an organism. They do not provide a benefit to the sufferer. The allergens are not harmful in and of themselves, since allergies are the exception, not the rule – pollen has no effect on me, but will ruin somebody else’s day. The idea of allergies as a criterion in natural selection strikes me as way too artificial – i.e. “those people who (do or don’t) have this allergy are more likely to survive and attract a mate, thus passing on this trait to the next generation.” There’s no benefit in being allergic or not, save that you don’t suffer allergic reactions if you’re not.
What’s the deal, fellow Dopers? Any thoughts on this? Any chance we might kick this one up to the Advisory Board or (gasp) Cecil Himself?
I remember reading that allergies (specifically an Immunoglobulin-E based immune response) are an unfortunate side effect of a mechaism evolved to combat parasites like roundworms. The rationale behind that assumption escapes me now.
“The world ends when I die. And as far as I’m concerned, the rest of the universe might as well call it a day too.” – Matt Groening
One theory I read and would love to hear verified/disproven is that allergies have become much more common since the advent of agriculture and the use of wheat flour to make bread.
The author’s premise was that the proteins in gluten are only partially digested and cross into the bloodstream where they resemble protein coatings of viruses and bacteria. They antogonize the immune system and set it up to respond to less similar substances - causing food allergies, hay fever and such.
I (obviously) don’t know anything about biochemistry, immunology, or that level of nutrition, so I’d love to hear that theory debunked or confirmed by someone in the know.
Interesting on both counts. And you have no idea how glad I am that there wasn’t a cut-and-dried answer posted by 7 people within an hour of my starting this topic.
My thoughts on your answers thus far (and I realize that you’re only repeating what you’ve heard):
Alphagene – It seems doubtful to my puny mind that a side effect like that could have such varied and far-reaching effects.
Phouka – How do explain people (like my brother) who are allergic to wheat?
Keep the ideas coming, team. Who knows? We may have just given a doctoral candidate somewhere a subject for his/her thesis.
My impression (mixture of “what I think I remember” and WAG) is that an allergy is a glitch in your immune system. I.e., it’s supposed to be making your body react to things, like eliminating the alcohol that somehow got into your blood stream after that party last night, or disabling that virus that you picked up. In the process, it’s calling on various things your body can do, like swelling up around a foreign particle that got embedded under your skin, and causing that thing that makes your nose itch get sneezed out. Instead, it hits on this pollen you inhaled and starts reacting to that.
Polycarp, alcohol itself isn’t handled by the immune system, though some of the other stuff in those drinks can provoke a response. But, as you say, allergies are probably just a glitch.
There’s some recent research suggesting that the increase in asthma cases in the last 20 or 30 years may be caused by the lack of dirt! Minor infections early in life (as you might get from soil bacteria and fungi) seem to make the immune system develop properly; without them the different parts get out of balance and cause extreme reactions. The original article was in Science 1997 January 3; 275: 41-42, on the Web at http://www.sciencemag.org/ , but they want you to register to see it. Go to a library instead.
Bob the Random Expert
“If we don’t have the answer, we’ll make one up.”
I think the basic premise is wrong: Who says allergies should be good for anything? I don’t think anyone has ever found a purpose (or, more neutrally, positive effects) to them. People don’t survive because of their allergies, but in spite of them. It’s definitely a glitch, as Polycarp said.
One interesting observation some researchers have made (sorry, no cite) is that the risk of allergies is increased in persons who have had very few infections, especially in their childhood. Vaccinations are also blamed sometimes in this context. The idea seems to be that your immune system may act up if it’s “bored”. This is definitely a problem that our forebears would not have had, given the medical and hygienic conditions of earlier ages.
One day at 28 years old, I woke up with Asthma. It was severe. After going through bouts of hives itching whatever, after going to both Johns Hopinks and Mayo, I was told two things.
Allergies come and sometimes they go.
Most can be controlled. (Mine were very severe and I learned how to control them. Though I never found the cause. The hives simply disapeared.
And finally the good news. People with allergies have low cancer rates. This is not to say you can’t get cancer but just that for some reason people who are allergy sufferers tend to get cancer less often.
I’m sorry. I found this old thread while searching for asthma information. I just had to answer.
One of the theories of late is that allergies are a side-effect, if you will, of a very good immune system. Before we had good hygiene, immunizations, clean drinking water, etc. the people who have allergies now would have been the survivors. What with all of those improvements in life-style these nice strong immune systems don’t have anything else to do so they start attacking proteins of harmless things. Sure, in the process the reaction might kill the animal it’s supposed to be protecting or something.
Another theory is the agriculture one. There’s more detail to it than just wheat. It says that people continue to overexpose themselves to certain pollens and foods through agriculture. While we used to only have to eat whatever foods were in season, now we tend to eat the same foods all year long and even every single day. This theory fits the patterns of most common foods eaten. In North America the most common food allergies are dairy followed by wheat, eggs, and soy. In Japan the most common food allergies are soy and rice.
