Energy drinks and junk food damage teenagers’ mental health, according to new research.
The rate of young people diagnosed with anxiety and depression has rocketed in the last few years, with many pointing to cyber-bullying and media.
However, new research by RMIT University in Melbourne has found another culprit: energy drinks and junk food.
According to the researchers, these products cripple developing brains with such an intense rush of dopamine hormones that they pose a ‘unique’ mental health risk to young people who consume too much.
Animal experiments have found an alarming link with taurine – an additive used in energy drinks.
Lead author Dr Christine Curran said it adds to concerns about them fueling teenage drinking as they are often mixed with alcohol.
She said: ‘Our review indicates we don’t know enough about the effects of high consumption of energy drinks and the ingredients found in them at this critical time in mammalian brain development.
‘Our recent findings in adolescent and young adult mice exposed to high taurine levels indicate there can be adverse effects on learning and memory and increased alcohol consumption in females.’
Another study also published in Birth Defects Research: The Teenage Brain said takeway meals could cause cause young people to become drink or drug addicts as they get older – as well as pile on the pounds.
Lead author Dr Amy Reichelt, of RMIT University in Melbourne, said junk food is not only not only bad for waistlines – but also for the teen brain.
She said: ‘Because key neurotransmitter systems in the brain responsible for inhibition and reward signalling are still developing during the teen years existing primarily on junk food could negatively affect decision making, increase reward-seeking behaviour and influence poor eating habits throughout adulthood.’
Dr Curran said taurine is found in high levels in the developing brain – boosting neurons and connections between brain cells called synapses.
Disruptions in levels of taurine have been reported in numerous studies of neurological disorders – including epilepsy and autism.
But Dr Curran said young mice whose diets were supplemented with the chemical performed worse in tests measuring their recognition of objects and were less soaciable.
She said elderly people might benefit from taurine supplements – or caffeine with which energy drinks are also packed.
But Dr Curran said: ‘It appears adolescents are not likely to benefit from supplementation and may, in fact, suffer ill effects from chronic ingestion of high doses.’
Dr Reichelt said a growing body of evidence has shown adolescence to be a critical period where exposure to alcohol, drugs and a high fat or sugar diet has ‘pronounced and enduring detrimental effects on cognition, behaviour and learning.’
She said: ‘In particular memory tasks reliant on the hippocampus are rapidly disrupted by high fat and high-sugar diets.’
One study of young people using a self-report diet questionnaire found the foods were linked with poorer performance on hippocampal-dependent memory tasks – independent of BMI (body mass index).
Animal studies have shown diets rich in saturated fats or refined sugars in early life reduces brain power compared to those commencing exposure during adulthood.
Rats exposed to a high fat diet from weaning demonstrated impairments in memory and learning as juveniles – but not as adults.
Similarly, mice fed a high fat diet for 11 weeks post-weaning had impaired memory whereas adults exposed to the same food from 12 weeks old for the same duration did not suffer.
Another recent study showed rats whose diets were supplemented with high fructose corn syrup – used in cakes, biscuits and ice cream – through adolescence had increased memory impairments compared to adults consuming the same solution.
Subsequent analysis found increased inflammation in the hippocampus of the adolescents.
Dr Reichelt said: ‘This indicates a general vulnerability to neuroinflammation within the adolescent – specifically in the hippocampus – in response to high-sugar diets.
‘The memory deficits also displayed after consumption of a high sugar diet is unique to adolescents, compared to adults.’
She said studies in humans have also indicated consumption of unhealthy diets, particularly those excessive in dietary fat, are associated with poorer cognitive functions and reduced executive performance in adolescents.
Obese teenagers have been found to have reduced executive functioning – which in turn have been further linked to less grey matter in frontal cortical regions.
Dr Reichelt said: ‘We propose poor dietary choices may derail the normal adolescent maturation process and influence neuro-developmental trajectories which can predispose individuals to dysregulated eating and impulsive behaviours.’
Two other reviews included in the journal found exercise could protect teenagers – but most aren’t doing enough.
Co-editor Dr Michiko Watanabe said: ‘One piece of good news is exercise might be the answer to steer teens away from certain exposures.
‘The long list of exercise benefits could motivate teens to get off the sofa.’