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Why is unpurified water or junk food bad?

  1. Sep 2, 2007 #1
    Doesn't our body rejects what it doesn't need? Then why do we die when we take poison? Unless our system cant digest it and get it out of its system I guess. I have heard of cases where a person takes too much poison and the body rejects it. Also of the science where when a person is biten by a snake, snake poison is used to treat him. How do those things work?

    Thx.
     
  2. jcsd
  3. Sep 2, 2007 #2

    Astronuc

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    Some poisons are absorbed and do damage before they can be removed.

    http://en.wikipedia.org/wiki/Neurotoxin
    Tetrodotoxin, for which there is no antidote, is found in several species of blue-ringed octopodes of the genus Hapalochlaena (where it was called "maculotoxin"), several starfish, an angelfish, parrotfish, pufferfish, cone snails, toads of the genus Atelopus, a polyclad flatworm, several species of Chaetognatha (arrow worms), several nemerteans (ribbonworms) and several species of xanthid crabs.
    http://en.wikipedia.org/wiki/Tetrodotoxin

    Then there are nerve agents - http://en.wikipedia.org/wiki/Nerve_agent
    http://en.wikipedia.org/wiki/Organophosphate - which are also used in insecticides

    Snake poison is used to make anti-venom, which is used to counteract the snake venom (poison).

    Unpurified water migh contain biological agents (e.g. bacteria), which might produce a toxin, or heavy metals. Metals such as lead or arsenic accumulate over time leading to nerve damage. Such heavy metals must be removed from the body with chelating agents which make the metal atoms more soluble so they can be exreted.
     
  4. Sep 3, 2007 #3
    So that would be mean that some kind of junk food are not bad for us b/c our body rejects them, right? Could you tell me which one those are? lol
     
  5. Sep 3, 2007 #4

    Astronuc

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    The term 'junk food' usually refers to sweets (loaded with simple sugar and perhaps fat) and snacks (starch, fat, salt, . . .) that provide little or no nutrition. A diet heavily weighted with junk food can contribute to obesity and perhaps vitamin and mineral deficiency.

    http://en.wikipedia.org/wiki/Junk_food - neutrality of article is questioned, but the paragraph cited pretty much sums up the situation accurately.
     
  6. Sep 3, 2007 #5
    I think it could be helpful if you figured out (and told us) exactly what you mean by 'reject.'
     
  7. Sep 3, 2007 #6

    Moonbear

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    I concur that this would be helpful since the body DOES mount an inflammatory/immune response to organisms in contaminated water. If the bacterial count is low enough, you may be able to fight it off with a healthy immune system, but when the response to the bacterial or amoebal infection is vomiting, diarrhea, and fever with sweats, and your only source of water is contaminated with the organism inducing the illness, dehydration rather than the primary infection may be what does you in.

    As for things like junk food, that's a whole different scenario, because it's not going to cause any immediate illness, and isn't even going to harm you at all if eaten in small quantities every now and then. It's a lot of calories for very little nutrients, and is mostly unhealthy because of the quantities people consume, especially when combined with sedentary lifestyles so they aren't burning off any of those excess calories. Of course, there are also added preservatives and such that are possibly also unhealthy in large quantities.
     
  8. Sep 3, 2007 #7
    I don't get this though, doesn't body take what it needs out of the food and then flushes the rest out? Are you telling me that body gets fooled?
     
  9. Sep 3, 2007 #8

    Danger

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    It's not a matter of the body being 'fooled'. That's almost like saying that someone who wanders into an alley gets 'fooled' by a mugger with a knife. There are some things that the body is just not equipped to protect itself from.
     
    Last edited: Sep 3, 2007
  10. Sep 3, 2007 #9
    I guess what I am trying to say is that when you eat something, if it has proteins, the body takes it from it and supplies it to(btw, where to the things we eat go?) but the rest flushes out. Are you saying that when body choose to select something out of something, it gets a little bit of bad stuff too b/c its filter is not the state of the art?
     
  11. Sep 3, 2007 #10
    well it is just that we really have no control over what goes in and what goes out of our body. the food we eat go though our digestive system and the work is all done there. and NONE of our bodies are state of the art! they are all the SAME!
     
  12. Sep 3, 2007 #11

    Danger

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    It's 'state of the art' in terms of human evolution. This isn't something that we can immediately alter on a whim.
     
  13. Sep 3, 2007 #12
    yup that is right and logical. you can change things to your way if u like it. you can only try. gd luck on it
    (visit my blog!)
     
  14. Sep 4, 2007 #13

    DaveC426913

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    There are many ways that the body can get in poor health from eating the wrong things.

    Poisons are designed to enter the body. They have chemical components that cause them to be taken up like eveything else.

    Junk food contains stuff we normally eat and digest (protein, carbs, fats, sugars) but in proportions that will eventually cause other problems (lots of fat will get deposited, causing obesity, lots of carbs and sugars will overload the pancreas abiliity to produce insulin, leading to Diabetes, etc.).

    Other foods contain chemicals that wreak havoc in our systems in other ways (caffeine, etc.)
     
  15. Sep 4, 2007 #14

    Moonbear

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    Our bodies did not evolve with an abundance of food, this is a relatively recent event of the modern world to not experience periods of famine or low food availability. Our bodies are very efficient at storing excess calories as fat reserves whenever we encounter them. Junk food (along with even the excesses of otherwise "healthy" food available and consumed in modern society) gets converted into fat very easily. While there is a healthy and necessary amount of fat reserves (this is discussed in another thread you started) to lubricate and cushion organs and to maintain energy reserves between meals, when this is greatly exceeded, as it is in many people today, it becomes pathological. As with many things, too little or too much fat are both problems for our bodies. Too much fat means we are experiencing metabolic problems associated with processing the excess (diabetes), cardiovascular problems from the excess lipids in our blood stream (atherosclerosis), musculoskeletal problems from carrying around that excess weight all day long, and further cardiovascular and respiratory problems from trying to pump blood through so much body mass.

    As for toxins and poisons, this are toxins and poisons precisely because they are things our body cannot rid itself of before they cause damage, or because they interfere with the normal mechanisms by which the body would do that.
     
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