Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Medical Soda acid vs fruit acid.

  1. Aug 10, 2010 #1
    Is the acid in salad dressing or fruit any better than the phosphoric acid in common soda pop?

    Or are the effects of acid only a matter of quantity? (on teeth, or on the lifetime of a small insect, or on general health.)
     
  2. jcsd
  3. Aug 12, 2010 #2
    I assume that you refer to the effects of acid on the teeth, which leads to some varied points. In salad dressing, you're dealing with vinegar (acetic acid), in fruit it's usually citric acid, and in soda carbonic acid is most prevalent. Compared to all of this, eating a piece of bread or some potato chips and not brushing/flossing is muuuuuuuch worse. You see, the effect of acid directly on the teeth is not the major issue, but the acid that is excreted by bacteria living in your mouth. They feed on starches and sugars, and the more those starches and sugars remain affixed to the teeth the longer the teeth are bathed in acid. The issue with fruit and soda is primarily the sugar content, not the acid, although carbonation and carbonic acid may be an extra contributing factor.

    So, a candy you suck on for 5 minutes is far worse than an orange you eat for 1, but much better than a handful of potato chips which leaves a starchy residue for hours or until you brush, have some sugar-free gum etc.

    As for general health, there is plenty of debate as to the damage that might be done by phosphoric and carbonic acid, possibly demineralizing bones and teeth, but there is nothing certain yet. I don't know of any study which shows that kind of risk for acetic or citric acids.

    As for the effect on the lifetime of an insect, that is just too vague. Has this helped?
     
  4. Aug 12, 2010 #3
    nismar is pretty spot on here, although the concerning acid in soda is mostly phosphoric, from what studies I have seen.

    I think the takeaway message here is regular brushing and flossing will help protect your teeth, while eating healthfully will help protect your body. Ignoring the acid, a piece of fruit is entirely unrelated to a can of soda. One provides fiber, phytochemicals, vitamins, minerals, etc. while the other is just sugar, flavorings, and food coloring. So if you can, just go with the fruit. And brush your teeth either way! :D
     
  5. Aug 12, 2010 #4
    wouldn't drinking a glass of water wash away some of the acids adhearing to teeth found in these things?
     
  6. Aug 12, 2010 #5

    Monique

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Just don't brush your teeth right after drinking a soda, it might do more damage than good.

     
    Last edited by a moderator: May 4, 2017
  7. Aug 12, 2010 #6
    Indeed, the best thing you can do is have a bit of cheese or milk, or some sugar-free gum. This is advice an Irish dentist gives on a regular basis to people who have the unfortunate combination of a starchy, sugary diet and poor dental hygiene.

    Dreiter: I stand corrected, and found this to confirm your point: http://antoine.frostburg.edu/chem/senese/101/consumer/faq/why-phosphoric-acid-in-soda-pop.shtml
     
  8. Aug 12, 2010 #7
    Yeah, that helped a lot. As for the insect thing, I just remember a teacher saying that worm (ok not an insect) bathing in a glass of cola would die a lot sooner than one placed in a glass of water.

    The question arose when I noted a parallel between fruit juice: water, fructose, and citric acid, and soda: water, sucrose and phosphoric acid. It seems like replacing a cola with a diet cola plus a multivitamin is just as healthy as a fruit juice, which is rather unsettling.
     
  9. Aug 12, 2010 #8
    Hmmm... a multivitamin plus a beer has more of what you need than any single juice, but whether or not that is healthy... I don't know.

    For the insect, I would have to believe that a worm is going to die MUCH faster in cola than in water, for a number of reasons, but I wonder how much faster one would die in:

    Coke-type cola.
    Sprite-type soda.
    Carbonated water
    Water with the addition of small amounts of citric, carbonic and phosphoric acids.
    Water with corn syrup
    Water with Caramel Coloring.
    Water with caffeine.

    I would be very interested to see which is more lethal, but probably not enough to drown a hundred or so worms. :wink:
     
  10. Aug 15, 2010 #9
    You also have to consider the relatively low efficacy of many multivitamins out there, combined with the fact that the diet cola + multi combination will still be devoid of the phytochemicals provided by the fruit juice. Again, the best choice is to eat a whole fruit, not the processed juice....
     
  11. Aug 16, 2010 #10
    Yeah, that seems to be the consensus. Except that the diet cola doesn't have any calories, which may also be a considerable advantage.

    Either way, it seems like fruit juices don't have have much going for them.
     
  12. Aug 16, 2010 #11
    It isn't so much that they have little going for them, rather that they skew the "good stuff" with a high sugar content. The fact is that eating a single whole fruit isn't going to give you your RDA of anything, whereas a vitamin may. It is feasible to make your RDA in a day with whole fruits and veggies, but to do the same with juice would pack in too many calories at the same time.

    Note: Juice made through a "juicer" that pulverizes the material leaving only fibrous material behind gives you the phytochemicals you need, but you're missing the fiber. Given that 2000-22000 calories doesn't give TONS of wiggle room, you can avoid the need for supplementation by just eating the real McCoy when possible.
     
  13. Aug 17, 2010 #12
    Thanks. BTW, the worm experiments would make a great science fair project. Even the school teachers wouldn't be able to predict the outcome. Real research for less than 10$!
     
  14. Aug 17, 2010 #13
    If you or someone you know does such an experiment, I'd love to hear about the results. Anyway, my pleasure, this thread has been a fun diversion, and I learned about the primary acid in soft drinks.
     
  15. Oct 15, 2010 #14
    Jaxter, what the hell does a cold drink have to do with ANYTHING? Sensitivity to temperature extremes can be normal, or a sign of damaged teeth, but that's just sensitivity... even then no harm is done. Please stop posting pure bull**** as if it were fact.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook