Caffeine and Heart Attacks .

Caffeine and Heart Attacks.
Andre Willers
14 Mar 2011

Synopsis:
Humans with 1 out of 2 defective copies of the gene P450 A12 (CYP1A2) on chromosome 15 are at least 64 times more likely to have a heart attack . (It governs enzymes in the liver that breaks down caffeine)

Discussion :
Source: J. Craig Venter , "A life decoded" , ISBN 978-0-141-01441-8 , p132 .
Somebody who should know .

A study of 4 000 persons over a year of coffee drinking showed risk of heart attack between 4+cups a day and 1 cup a day was in a ratio of 64:1 . These persons included the mixture of genes .

A separate test on only persons with both fully functional genes showed a less than 1% chance with 4+ cups of coffee per day .

I presume that if you have two bad copies of the gene , extreme caffeine intolerance will result , as it cannot be metabolized but only excreted .Basically , you die .

So , the system is very sensitive (by a factor of 64) to the mutation of one gene .

How do you tell if you have only one functioning gene ?
Absence of habituation .
If coffee always hits you the same way or more , then your liver is not breaking down the caffeine fast enough to compensate for intake . You have one defective gene ,

Is this good or bad ?
There is some historical evidence that caffeine or some metabolite competes with the CCR5 receptor site . This is the real baddy receptor site , where nasties like Black Death , smallpox , some flu's, etc enter the cell .
There was then strong positive selection for increasing caffeine tolerance , as it gave some protection against infectious diseases (apart from boiling the water)

Note the major usage of caffeine by doctors . This is usually ascribed to be kept alert , but it actually started as a fairly effective anti-infective agent .

It definitively kept them alert , mainly by keeping them alive .
As usual , humans got it the wrong way around .

The race between a heart attack and disease .
Having one defective gene means that caffeine stays around longer , but it causes heart problems if overindulged .

As usual with humans , the overindulgence won and selection heavily favoured two functional genes . The "more is better" school .

This results in all those huge coffees you get in Starbucks .
Also that doctors and other major caffeine imbibers will have more normal heart attacks , as some of them will still have one defective gene .

Historical notes :
Note the small old Chinese Tea-cups . (A cup of tea has about half the caffeine content of a cup of coffee .)
Or the original Turkish or Arabic cups .
All are small , because most people only had genes to slowly break down the caffeine .
Calculate optimals by using the 64 ratio .

If you have only one functioning gene.
Don't despair .
If you are partially caffeine intolerant , don't despair . Just drink less .
The effect , both stimulation and infection control is nearly the same .

Half a cup (a demi-tasse) a day of coffee will do the same .In the morning is best (Why do think they made all those millions of demi-tasse cups ?)
Or two demi-tasse's of tea a day . Or 4 chinese cups . You get the drift .

Children :
Treat them as having only one functioning gene.But this places those with two fully functioning genes at greater risk of disease . So , sort them out as soon as possible . A genetic test is preferable , otherwise just watch their behaviour after giving them a cup or two of coffee .

Why does caffeine compete with access to CCR5 receptor site ?
The old Plant-Herbivore Wars .
Plants dependant on cultivators (ie humans) benefit from reduced human susceptibility to disease . Those plants flourished , because humans survived to care for them . And so we are off to the races .

Plants are cultivating humans , and humans are cultivating plants .
A mutual bonsai .

Give a dinosaur a flower .

Andre

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