While "brain foods" are in fashion, "mood foods" may come into their own with new evidence that the B vitamins can affect the mental health and behaviour of children and teenagers.
And, according to a senior researcher, it is easy to include the vitamins in your diet because they are found in numerous foods. These include whole grains, nuts, seeds, legumes, and fruit and vegetables.
But the body has a limited capacity to store most of the B vitamins, which is why it is important for people to eat them regularly as part of their diet, says Wendy Oddy, head of nutritional research at the Telethon Institute for Child Health Research.
Professor Oddy is a senior author in the first study to discover a direct link between a lower intake of vitamins B1, B2, B5, B6 and folate and the prevalence of externalising behaviour problems - such as aggression and delinquency - in adolescents at 17 years.
The study also found a reduced intake of vitamin B6 and folate was associated with higher prevalence of internalising behaviour, such as being withdrawn, anxious or depressed.
"There is a great message in this in how diet may help prevent mental-health problems," Professor Oddy said.
"B vitamins are essential for normal central nervous system and brain function."
Professor Oddy said up to 20 per cent of children and adolescents suffered from a mental-health problem at any one time.
Lead author Carly Herbison said B vitamins were essential for the production of neurotransmitters, like serotonin, which modulated behaviour in humans and could contribute to feelings of wellbeing and happiness.
"Previous studies have shown that externalising mental health and behaviour problems developed during adolescence are related to a higher risk of offending and substance abuse later in life," she said.
Furthermore, several studies have found that young prisoners or delinquent school children, supplemented with B vitamins and minerals, decrease their incidence of aggressive behaviour.
The WA study drew on detailed nutritional and mental-health data collected from participants in the Raine (WA pregnancy cohort) study when they were 17 years old. It was published in the international journal Preventive Medicine.
Professor Oddy said the intake of fruit and vegetables of the Raine teenagers at 17 years was low and did not meet the recommended intakes of B vitamins.
The Raine study had also shown that the overall diet of many Raine teenagers was poor.
"They are on the run, they are drinking an awful lot of soft drink and energy drinks, eating a lot of take-aways and they don't really go for wholegrain breads but more for white breads, which have had the B vitamins stripped from them," Professor Oddy said.