Scientists are only now beginning to unravel exactly
why alcohol can prove so toxic to our brain cells.
Professor Anne Lingford-Hughes, chair in addiction
biology from Imperial College London is at the
forefront of research into alcohol’s effects on the
brain.
“Not only are we increasingly realising that alcohol
effectively shuts the whole brain down – and can
even trigger inflammation within the brain - but
we’re also seeing how long these effects last.
This knowledge is crucial to understanding alcohol
dependency, and giving people effective treatments.”
Here Professor Lingford-Hughes explains what happens
to our brain when we have a drink
That first swig of wine or beer rapidly causes
changes in two types of brain chemicals.
These orchestrate much of alcohol’s effects on our
thoughts, feelings and coordination.
"One of these chemicals, called GABA, acts like a
sedative to calm the brain down, while the other,
called glutamate, excites the brain and makes it
more active," says Professor Lingford-Hughes.
Alcohol quickly increases GABA function, which is
why a drink relaxes us.
One of the brain areas first affected by this
imbalance in GABA and glutamate is the frontal lobe,
explains Professor Lingford-Hughes, which is found
just behind the forehead, and governs traits such as
attention, planning and impulsivity.
"The frontal lobe is exquisitely sensitive to
alcohol - this is why people quickly become
disinhibited.
As they drink more, their ability to think straight
and integrate all of their thoughts become lost."
One of the next areas of the brain to be affected is
the cerebellum, which sits at the base of your brain
at the back of the head, and is crucial to
controlling movement.
"If you paralyse this through alcohol, your
movements become uncoordinated, and your speech
slurred.
The muscles across your whole body become affected -
even in your eyes.
This is why your vision becomes blurred – although
your eyes are still seeing fine in terms of vision,
your eye muscles aren’t working properly so each eye
isn’t looking in the same direction.”
Those fuzzy memories from the night before are due
to an imbalance in the part of the brain caused the
hippocampus, which is vital for memory. “This area
of the brain is sensitive to changes in glutamate,
and so when levels start to swing out of control, it
struggles to lay down new memories.”
When we stop drinking, our brain struggles to
re-adjust to the situation.
“Once alcohol is out of the blood stream, GABA
function falls, but glutamate – which excites the
brain - is still very high.
This can lead to anxiety, shakiness and poor sleep.
If you have been drinking very heavily, this sudden
change can even lead to fits. Levels of another
neurotransmitter in the brain – dopamine – are also
affected which can lead to low mood.”
And high glutamate levels are bad news for our brain
cells.
“Large amounts can prove toxic, as it seems to
destroy all the delicate connections between brain
cells - rather like pruning back a shrub until just
a bare stump is left.”
The alcohol is going out of the system and the
brains begin to readjust. We’re still unsure how
long this takes but it could be a number of days, if
not weeks. It will certainly take longer the older
you are, as the brain takes longer to recover.”
Although Professor Lingford-Hughes is not suggesting
everyone abstains from alcohol for the sake of your
brain cells she urges sticking to sensible amounts.
For more information
Imperial College London
Link...
MDN |