I have an allergy to quinine.  It was discovered by accident when I
was a toddler. I was given tonic water and reacted with a rash.  My
skin has always been sensitive and reactive to certain foods.  It
wasn't until recently that I read about quinine-like substances in
certain fruits, such as grapefruit.  My question is, what other foods
have compounds with a similar chemical structure to quinine?  Thanks
kindly for your help.

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Request for Question Clarification by grimace-ga on 02 Jul 2002 12:18 PDT

Hi,

Do you happen to recall where you read that grapefruit has
quinine-like properties?

I suspect that you may have read research about the possible
inhibition of CYP3A4 uptake from quinine (when taken as a medicine) by
grapefruit juice. Might this be possible?

You can read more here:

Effects of Grapefruit
http://organtx.org/dc/grapefruit.htm

"These results suggest that there is no significant interaction
between the parent compound quinine and grapefruit juice, so it is not
necessary to advise patients against ingesting grapefruit juice at the
same time that they take quinine..."

I'd be surprised if grapefruit and quinine had similar structures, but
I haven't located any chemical structures for grapefruit yet. Here's
the structure for quinine:

Quinine: Chemical Structure
http://omlc.ogi.edu/spectra/PhotochemCAD/html/quinine(0.05M_H2SO4).html

Sorry to be long-winded! Answers to my first two questions would be a
great help.

---

Clarification of Question by angel123-ga on 02 Jul 2002 13:51 PDT

Hello,

Thank you for your interest in my question.
The source was a message on usenet (appended below)  
I wrote to the author of this message about a month ago 
for more information, but did not hear back from that person.

I am aware that grapefruit juice can interract with
certain medications.  What I wanted to know is
whether the reaction I am getting to certain foods
and beverages might be related to my quinine allergy.

If the chemical composition of grapefruit had something
in common with that of quinine, maybe it would explain 
my reaction to grapefruit.  I'm curious about apples,
tomoatoes, and other foods which seem to be problematic
for me.  They might be totally separate allergies.
But just as someone who is sensitive to birch trees
is likely to be sensitive to apples, I'm interested in 
possible cross-reactions from my quinine allergy.

Here is a quote from the posted message:

Subject: Re: allergy to citric acid 
Newsgroups: alt.support.food-allergies
View: Complete Thread (7 articles) | Original Format 
Date: 1999/01/26  

"Allergy to citrus fruit is usually a quinine allergy.  All citrus fruit
contain quinine or quinine-like compounds in their pith; grapefruit has
quite a lot, hence its bitter taste.  Quinine often stimulates histamine
release so it's entirely plausible it would produce migraines."

Hi,

Well, I've found another online reference to quinine content in
grapefruit:

"The grapefruit contains a natural 'quinine' and hence is valuable in
the treatment of malaria. This 'quinine' is also beneficial in
feverish colds."

http://www.indiangyan.com/books/healthbooks/food_that_heal/grapefruit.shtml


The other fruit to watch out for is the humble cranberry:

"CRANBERRIES  Fresh cranberry juice is a powerful healing tonic filled
with quinine which changes to hippuric acid in the liver."

Fruit Guide
http://www.freedomyou.com/recipes/Fruit%20Guide.htm


Quinine is also related to coffee (they're both members of the
Rubiaceae family), and the bitterness in some coffee beans can be
attributed to high quinine content:

"Bitter: a basic taste characterized by solution of quinine, caffeine,
and certain other alkaloids."

Beans
http://www.joe.co.il/html/coffee_dictionary.html


Quinine is also used as a flavouring in liqueurs like Campari,
Dubonnet, Byrrh, Amer Picon and other bitter tipples. You would do
well to avoid bitter cocktails! Note that quinine is used in bitter
lemon mixer as well as tonic water.

Dictionary of Alcohol
http://homepages.ihug.co.nz/~topkiwi/alcohol.html


I haven't *yet* found any references to quinine content in apples or
tomatoes, but I'm still looking and will post if I find anything
positive.

So: no grapefruit juice, no cranberry juice, no coffee, no gin and
tonic and no cocktails! May I recommend a cup of tea?

grimace

Thank you for locating this information for me.  It's much appreciated,
especially the part about coffee, of which I was unaware.  Iced Cappuccino's
seemed too good to contain quinine.  Thanks again, and best wishes.