Adding Milk To Coffee Doesn't Impair Zn-chelating Capacity

Discussion in 'Coffee' started by Gabriel, Oct 1, 2013.

  1. Gabriel

    Gabriel Member

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    I wondered whether addition of milk to coffee impairs its chelating activity. While I found no studies for iron, I came across one study that found that the chelating capacity of zinc was not impaired. Guess that is good news for all the coffee+milk drinkers.

    Effect of Roasting on Properties of the Zinc-Chelating Substance in Coffee Brews

     
  2. charlie

    charlie The Law & Order Admin

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    So coffee removes zinc?
     
  3. OP
    Gabriel

    Gabriel Member

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    I'm not sure. In this study they tested one component of roasted coffee, named ApV. This one can chelate zinc. The effect of whole coffee may be different.
     
  4. charlie

    charlie The Law & Order Admin

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    I think that would be a bummer if it chelates zinc. :(
     
  5. OP
    Gabriel

    Gabriel Member

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  6. OP
    Gabriel

    Gabriel Member

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    Bad news: This in vitro study tested whole coffee and found that coffee significantly reduces the bioavailability of zinc, even more than it reduces iron.

     
  7. charlie

    charlie The Law & Order Admin

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  8. jyb

    jyb Member

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    That would be quite problematic.
     
  9. OP
    Gabriel

    Gabriel Member

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    There may be differences to what really happens in the body, as this was just an in vitro experiment.
     
  10. OP
    Gabriel

    Gabriel Member

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    More food for thought:

    According to this study in rats, coffee impaired iron but not Zn or Cp in nonpregnant rats. However, in pregnant rats lower levels of zinc in the placenta were found.

    In this correlative study on women, coffee consumption was paradoxically positively correlated with both serum iron and zinc. The positive correlation was stronger for iron than for zinc. High orange juice consumption was associated with lower zinc status. Vitamin C is known to increase iron and decrease zinc absorption.

    This study looked at the effect of discontinuing coffee consumption in young toddlers on serum zinc, copper and iron. They found that discontinuing coffee did not really affect any of the metals.
     
  11. Dan Wich

    Dan Wich Member

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    Interesting stuff, thanks Gabriel. I assumed that you'd made a mistake in your sentence about coffee + toddlers, but no, "Coffee is one of the first liquids given to infants in Guatemala."

    Huh.
     
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