I am looking for concrete scientic evidence that eating garlic is bad
for your health. What harmfull chemical effect does it have on the
body? Any studies that have been done to prove its harmful effects.
     I have heard something about it 'crossing the blood line'. That 
vegetarians who do yoga in India consider it more harmfull than meat.
Any evidence to support this belief?

Most of the evidence is to the contrary. Garlic seems to lower
cholesterol and fight free radicals. It may even be a cancer
preventive, according to some studies.

It'll give you bad breath.

Are you a vampire?  Because it's bad for vampires...

I used to take a Garlic pill daily (at the suggestion of my Doctor)
but when I had an op, the anaesthetist shook her head at the Garlic.

'It can cause blood clots', she advised.

So, I've never taken a garlic pill since.

Do you reckon I can shift my unwanted pills on ebay?

That's interesting, Bryan. Everything I've read about garlic says that
it's an anticoagulant. I'll have to ask a doctor friend of mine.

dtcc

As a physician, I have no idea what "crossing the blood line" means. 
I also doubt that vegetarians who do yoga in India have done a lot of
scientific research to support the claims that it is more harmful than
meat, or in what regard.  From what I have seen on this subject these
substances are more to be avoided due to their stimulating qualities
which can interfere with achieving serenity than due to any direct
effect on health.  However some sites which discuss the subject in
greater detail actually state garlic can be useful for promoting
'dynamism' or stimulating those who need to take action, and may be
useful in small amounts to aid in digestion which can promote
serenity.  Because these belief systems are so much different than the
Western view of health, it is unlikely you will find a lot of hard
evidence to support it.  Doesn't mean that it is wrong, but rather
that it is not necessarily amenable to our research methods to answer
the question.

From Pizzorno's Textbook of Natural Medicine:

"Based on a great deal of clinical research, the dosage of a
commercial garlic product should provide a daily dose equal to at
least 4,000 mg of fresh garlic. This dosage translates to at least 10
mg alliin or a total allicin potential of 4,000 mcg.

For the vast majority of individuals, garlic is non-toxic at the
dosages commonly used. For some, however, it can cause irritation to
the digestive tract, while others are apparently unable to effectively
detoxify allicin and other sulfur-containing components. Prolonged
feeding of very large amounts of raw garlic to rats results in anemia,
weight loss and failure to grow.[63] Although the exact toxicity of
garlic has yet to be definitively determined, side-effects are rare at
the dosage recommended above"

It does indeed inhibit platelet aggregation, and thus have an
anti-clotting effect.  This would probably be of at least as much
concern for surgery as causing blood clots, so perhaps probono
misunderstood the anesthetist.

I couldn't find anything that was much different than the above quote,
although it may be more toxic for dogs and cats (and maybe horses).

Hi, ac67

Great Comment ... Fascinating!

I really did hear and understand the anaesthetist correctly but,
subsequently, I was unable to find any corroboration. Now, I know why!

Many thanks

Bryan

Declan here. Really appreciate the comments. Especially by the good
doctor.  About safe dosages, I have a friend who eats on a regular
basis, 5 whole cloves of garlic (for detox purposes). This then
exceedes any 'reccomended dosage'. I wonder if this might be harmfull?
 I just found  on 

http://www.vegan-straight-edge.org.uk/phytotox.htm

'If natural is good, then Hemlock is natural, but for us (as great
apes), it would not be good to eat, and it would not be at all
natural, in fact the opposite would be true on both counts. However
hemlock is eaten with relish by goats, sheep, horses and mice. But
what of the things that are generally accepted as foods, but none the
less may be toxic.

*	Onion and Garlic are often touted as being "good for the blood"-
in fact both contain oils that inhibit blood platelet aggregation.'

And on a site in german 
http://www.is-is.de/page/haupt.htm

I have been told it says something like this

'Because garlic crosses  the ?brainbloodborderline? , it is toxic and
destroys  braincells. That is why it smells everywhere in the body. '

I also dont understand what 'brianbloodborderline ' is and have asked
them for an English translation of all they have to say about garlic.
Thanks all.

I have found various websites touting herbal remedies recommending
garlic anywhere from 1-2 cloves up to 10-20 cloves per day, so no
doubt people do this.  It is difficult to find studies of toxicity
from this, particularly long term effects.  In the short term, doses
in this range produce primarily GI symptoms - heartburn, upset
stomach, nausea, diarrhea, etc.  Harder to say what the long term
effects are.

In regards to the German site, I think what they are referring to is
commonly known in the US medical literature as the blood-brain
barrier.  Most tissues allow most chemicals in the blood to freely
diffuse into them.  The brain is much more selective in what can come
from the blood into brain tissue.  This can cause problems or be
helpful. For instance, if an antibiotic can't cross the blood-brain
barrier, it is useless for meningitis.  Most over-the-counter
antihistamines, such as Benadryl can cross the barrier, which is why
they cause drowsiness.  The non-sedating antihistamines don't cross
the barrier, so they can still fight allergies without making you
sleepy.

The fact that something can cross the barrier does not automatically
make it toxic, and I have not found anything that really indicates
garlic is toxic to brain cells, but I can keep looking.  I did find
some references which actually suggest (but certainly don't prove)
that garlic may protect against Alzheimers.

Hmm ... here is my two cents on what I found:

Garlic can counter the effects of bifidus and lactobacillus cultures
taken to restore normal digestion.

It can also cause stomach upset.

Raw garlic can cause heartburn and flatulence.

If already on blood thinning drugs like warfarin (coumadin), garlic is
not a good idea since it would add to the drug's effect.

Nursing mothers should use with caution because it might cause colic in some babies.