By SARAH GRIFFITHS and FIONA MACRAE
Caffeine-laden fizzy drinks could be stopping children’s brains from developing properly, scientists have warned.
They believe that by preventing deep sleep, caffeine interferes with the development of the brain during adolescence.
This is a critical time for the brain, when problems in development can lead to schizophrenia, anxiety, drug use and personality disorders.
Researchers experimented on rats, but say the findings raise concerns for children and teenagers, some of whom consume large amounts of caffeine from colas and energy drinks.
Between 300 and 400mg of caffeine – four cans of energy drink a day or three or four mugs of coffee – could make a difference, the study suggests.
A can of the popular energy drink Red Bull, for example, contains 80mg.
The Swiss research focused on the development of the brain during the teenage years. As it prepares for the demands of adulthood, synapses, or connections between cells, that are not needed are eliminated.
It is thought that sleep is crucial to this process. Professor Reto Huber, of the University Children’s Hospital in Zurich, said: ‘This optimisation presumably occurs during deep sleep.
‘Key synapses extend, others are reduced; this makes the network more efficient and more powerful.’
Prof Huber said that when young rats were given caffeinated drinking water, they got less deep sleep than those who drank plain water.
Their brains also had more connections in them at the end of the study – meaning the pruning back process had been disturbed, the journal PLoS ONE reports.
A spokesman for the researchers said: ‘Children’s and young adults’ average caffeine consumption has increased by more than 70 per cent over the past 30 years and an end to this is not in sight.
‘The drinks industry is posting its fastest-growing sales in the segment of caffeine-laden energy drinks.
‘The brain goes through a delicate maturing phase in puberty, during which many mental diseases can break out.
‘And even if the rat brain differs clearly from that of humans, the many parallels in how brains develop raise the question as to whether children’s and young adults’ caffeine intake is really harmless or whether it might be wiser to abstain from consuming the pick-me-up.’
Another recent study suggested sugar-laden fizzy drinks made children as young as five violent, withdrawn and distracted.
HOW MUCH CAFFEINE IS TOO MUCH?
A recent study found a large cup of Starbucks coffee contains more than three quarters of a person’s ‘safe’ daily dose of caffeine.
The 16oz ‘Grande’ coffee is said to contain nearly double the recommended limit for a pregnant woman, while a typical home-made 8oz cup of coffee is well above a 10-year-old’s daily allowance.
But scientists stress that such statistical averages can vary widely from person to person, with factors such as gender and genetics having an impact on tolerance levels.
A person’s tolerance can also be affected by other drug use, with women who take the contraceptive pill breaking down caffeine slower, and smokers process the stimulant faster than non-smokers.
A study by the government regulatory agency Health Canada concluded that the average person can have up to 400mg of caffeine a day without experiencing negative affect, such as anxiety or heart problems.
The average allowance for a pregnant woman is 200mg, according to the Food Standards Agency, and 75mg for a 10-year-old.
A 16oz Starbucks coffee has 330mg of caffeine, according to a table compiled by Chemical and Engineering News but the coffee chain denied the findings, saying their Grande contains 140mg of caffeine.
University of Florida’s director of forensic toxicology, Bruce A. Goldberger, told Chemical and Engineering News: ‘People often don’t understand the potential risk of these beverages.
‘Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects.’
A fatal dose of caffeine is thought to be around 10g – equivalent to around 75 8oz cups of coffee or 120 cans of red bull consumed within a few hours.
Source: Mail Online
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