Male Susceptibility to Parasites May Help Explain Shorter Lifespans

Scientific American ^ | September 20, 2002 | Sarah Graham

[PatrickHenry]

In Westernized societies, women tend to outlive men. The established explanation for this inequality is that males undertake more risky behavior than females do and, as a result, perish prematurely. But new research published today in the journal Science suggests that parasites could be at least partially responsible.

Sarah L. Moore and Kenneth Wilson of the University of Stirling analyzed parasitic infections in 355 nonhuman mammal species and found that males were more likely than females to succumb to parasites. What causes this small but significant increase remains unclear. With their generally larger size, males may just make more attractive targets. Alternatively, because testosterone can suppress the immune system, it is possible that males are less able to protect themselves from a parasite's harmful effects. In an accompanying commentary, Ian P.F. Owens of Imperial College London suggests the findings may have implications for male mammals of the human variety, too. "In the United States, United Kingdom and Japan, men are approximately twice as vulnerable as women to parasite-induced death," he writes. In countries with a higher overall incidence of deaths due to parasites, such as Kazakhstan and Azerbaijan, men are four times as vulnerable as women are. "The next step," Owens concludes, "is to discover more about the precise physiological mechanisms that lead to the unusually high susceptibility of large mammals to parasitic diseases."

[PatrickHenry]

Now you know why women live longer than men.

[PatrickHenry]

Parasitic ping.

[Happygal]

Do parasites include ex wives?

[Cogadh na Sith]

Yeah, the worst parasite infestation is called 'a wife'....

[white trash redneck]

Interesting thought, but since parastitic diseases are not much of a threat in industrialized countries, yet the male-female mortality gap persists, I suspect there's more going on. Of course, if I got up off my butt and went to the library to read the original article in Science, then maybe the authors would clear up my confusion.

[wattsmag2]

I ain't goona touch this one.

[VRWCmember]

I thought most women would say men ARE parasites.

[VadeRetro]

There's some virus that lurks in cat crap and causes dementia in humans. Every time my cat craps on the floor I go ballistic.

[ofMagog]

Crew will fall in for delousing, all except Scuttlebutt and Thud. Nothing would live on them.

[PatrickHenry]

Alternatively, because testosterone can suppress the immune system, it is possible that males are less able to protect themselves from a parasite's harmful effects

Ah, the price we pay for our manhood!

[general_re]

Every time my cat craps on the floor I go ballistic.

Could be worse - I had an ex-girlfriend whose cat used to crap on the pillows when nobody was looking. It was the cat or me, and the cat won. Good riddance. ;)

[monkey]

The established explanation for this inequality is that males undertake more risky behavior than females do and, as a result, perish prematurely.

There is no such established explanation. That would certainly be low on the list.

The best explanation for why women outlive men is because they are smaller. Within a species, small mammals outlive big ones; the big animals age faster. There have been studies (albeit weak, more like calculations) that have shown that once corrected for weight, men and women have similar lifespans.

[billorites]

"In countries with a higher overall incidence of deaths due to parasites, such as Kazakhstan and Azerbaijan, men are four times as vulnerable as women are."

None of these countries exactly lead the world in hand washing.

[Feiny]

What about Janet Reno? How do you classify her...man, woman...or yeti?

[f.Christian]

No one doubts the improbability of events. Your existence is highly improbable. So is mine. Think of all the events in just the past 100 generations which could have caused any of our ancestors to behave differently than they did. Yet all the past events happened, naturally, step by step, and here we are, so mere improbability is not much of an issue.
"The facts upon which evolution theory is based are rather well established. Mutations happen. They really do. And new species appear over time, really. And they appear in form and DNA to be related to pre-existing species. No joke, that's the evidence. In every generation, those best suited for the game of life are most likely to breed the next generation. Mutation and natural selection. And time, lots of time. They're the stuff of evolution."

"The results are always going to be seen as improbable in retrospect, but that's how things happen. It's such a reasonable explanation that there's no need to wave it all away and grasp instead for an external "designer" for whom there is no evidence at all.

"So I don't see ID as an "honest attempt" to deal with improbability. Rather, it's a clever attempt to confuse the poorly trained public with slick (but unscientific) patter."

353 posted on 9/19/02 2:24 PM Pacific by PatrickHenry

[Chancellor Palpatine]

I'm not saying a word. Not me. I am the very soul of discretion, good taste and wisdom.

[Frohickey]

But the study did not look into the effects of the human mammal parasite that afflicts most men. Positive indication of a parasitic infestation is when you hear 'Honey, can you take out the trash?' or 'Honey, can you feed the baby?'.

Also, 'No, honey, why do you need more than one gun?', or 'Do these shoes make me look fat?' :)

[Jonathon Spectre]

Males are susceptible to parasites?

Well, most men do end up married...

>ducks and then runs like hell<

[stanz]

I doubt that any article published by Scientific American is slick unscientific patter.

The question of why women outlive men has been circulating for ages. I'm not familiar with the effects testosterone may have on the immune system. What has been popularly suggested is the fact that throughout our evolutionary history, females tended to outlive the males due to the need for continued nurturance of the young. How this may make them less susceptible to parasites is another issue.

[Bon mots]

Now I know why I hate cats. Thank you for that post. Now I won't feel bad the next time I run one over.