From: sbharris@ix.netcom.com (Steven B. Harris)
Subject: Re: toxins in vegetables
Date: 09 May 1996
Newsgroups: sci.med,sci.med.nutrition,rec.gardens,alt.folklore.science,
	sci.bio.botany,sci.skeptic,misc.health.alternative,aus.gardens

In <4mrpgn$vm4@taco.cc.ncsu.edu> kdmuelle@unity.ncsu.edu (Keith Downing
Mueller) writes:

>John Savage (koala@sydney.dialix.com.au) wrote:
>> Camilla Cracchiolo <camilla@primenet.com> writes:
>> >I need info on toxins in common vegetables and whether the amounts
>> >people eat of certain ones should be limited. I read an interview with
>> >biologist Margie Profit where she discussed her theory that kids and
>> >pregnant women avoid certain vegetables as an evolutionary adaptation
>> >to the presence of toxic chemicals. I realize her theory is quite
>> >controversial, but it seems like a logical corolary would be that it's
>> >probably not too hot to eat certain ones every day or in large
>> >amounts.
>
>Tomatoes contain a steriodal glycoalkaloid, tomatine. Young developing
>fruit contain tomatine but as the fruit ripen it beocmes degraded to less
>than ).04% of the fresh weight.
>
>the lethal dose (LD50) for tomatine is said to be 0.5 grams per kg of
>body weight.
>
>assuming a 150lb individual (~70kg) and an average fruit weight of 9oz
>(~250g), it would require the compsumption of approximately 350000
>tomatoes.


Hardly surprising.  Green tomatoes don't want to be eaten.  Red ones do.
That's WHY they turn red and sweet-- it's a sign that says "eat me" to
us primates (no jokes, please).  Evolution would seem unlikely to let a
fruit do all that, while keeping it full of compounds which were poisons
for the young of the animals it's trying to lure.

To the extent that morning sickness keeps women from eating ripe fruit,
it's an evolutionary screw-up.  Such screw-ups do persist in animals,
but only if they are from new mutations, or else side effects of design
aspects which have other far more positive counterbalancing effects.
Those effects are what to look for in morning sickness.  It's already
known that mothers who have morning sickness have higher levels of
hormones, and are less likely to suffer miscarriage.  Why?  The answers
are not necessarily so indirect as some effect on diet.  The idea that
the effect is direct is a lot simpler hypothesis, with even more
evidence behind it (ie, we know that higher hormone levels induced
artifically ALSO inhibits miscarriage; that was why stilbesterol shots
were given in days of old, before THEIR side effects were understood).

                                       Steve Harris, M.D.