Junk food diet linked to lower IQ - study

Toddlers who have a diet high in processed foods may have a slightly lower IQ in later life, according to a British study described as the biggest research of its kind.

The conclusion, published on Monday, comes from a long-term investigation into 14,000 people born in western England in 1991 and 1992 whose health and well-being were monitored at the ages of three, four, seven and eight and a half.

Parents of the children were asked to fill out questionnaires that, among other things, detailed the kind of food and drink their children consumed.

Three dietary patterns emerged: one was high in processed fats and sugar; then there was a "traditional" diet high in meat and vegetables; and finally a "health-conscious" diet with lots of salad, fruit and vegetables, pasta and rice.

When the children were eight and a half, their IQ was measured using a standard tool called the Wechsler Intelligence Scale.

Of the 4,000 children for which there were complete data, there was a significant difference in IQ among those who had had the "processed" as opposed to the "health-conscious" diets in early childhood.

The 20 percent of children who ate the most processed food had an average IQ of 101 points, compared with 106 for the 20 percent of children who ate the most "health-conscious" food.

"It's a very small difference, it's not a vast difference," said one of the authors, Pauline Emmett of the School of Social and Community Medicine at the University of Bristol.

"But it does make them less able to cope with education, less able to cope with some of the things in life."

The association between IQ and nutrition is a strongly debated issue because it can be skewed by many factors, including economic and social background.

A middle-class family, for instance, may arguably be more keen (or more financially able) to put a healthier meal on the table, or be pushier about stimulating their child, compared to a poorer household.

Emmett said the team took special care to filter out such confounders.

"We have controlled for maternal education, for maternal social class, age, whether they live in council housing, life events, anything going wrong, the home environment, with books and use of television and things like that," she said.

The size of the study, too, was unprecedented.

"It's a huge sample, it's much much bigger than anything anyone else has done," she said in an interview with AFP.

Emmett said further work was needed to see whether this apparent impact on IQ persisted as the children got older.

Asked why junk food had such an effect, she suggested a diet that was preponderantly processed could lack vital vitamins and elements for cerebral development at a key stage in early childhood.

"A junk food diet is not conducive to good brain development," she said.

The paper appears in the peer-reviewed Journal of Epidemiology and Community Health, published by the British Medical Association (BMA).

PROMOTED VIDEO
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
Voices
Pupils educated at schools like Eton (pictured) are far more likely to succeed in politics and the judiciary, the report found
voices
Arts and Entertainment
Simon Cowell is less than impressed with the Strictly/X Factor scheduling clash
tvSimon Cowell blasts BBC for breaking 'gentlemen's agreement' in scheduling war
News
Orson Welles made Citizen Kane at 25, and battled with Hollywood film studios thereafter
people
News
Brad Pitt and Angelina Jolie reportedly married in secret on Saturday
peopleSpokesperson for couple confirms they tied the knot on Saturday after almost a decade together
Sport
footballAnd Liverpool are happy despite drawing European champions
News
i100
Arts and Entertainment
tv
News
i100
Arts and Entertainment
Diana from the Great British Bake Off 2014
tvProducers confirm contestant left because of illness
Arts and Entertainment
Lisa Kudrow, Courtney Cox and Jennifer Anniston reunite for a mini Friends sketch on Jimmy Kimmel Live
tv
Life and Style
fashion

Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Client-Side web developer (JQuery, Javascript, UI, JMX, FIX)

    Negotiable: Harrington Starr: Client-Side web developer (JQuery, Javascript, U...

    Structured Finance

    Highly Competitive Salary: Austen Lloyd: CITY - An excellent new instruction w...

    SQL Server Developer

    £500 per day: Harrington Starr: SQL Server Developer SQL, PHP, C#, Real Time,...

    C#.NET Developer

    £600 per day: Harrington Starr: C#.NET Developer C#, Win Forms, WPF, WCF, MVVM...

    Day In a Page

    Ukraine crisis: The phoney war is over as Russian troops and armour pour across the border

    The phoney war is over

    Russian troops and armour pour into Ukraine
    Potatoes could be off the menu as crop pests threaten UK

    Potatoes could be off the menu as crop pests threaten UK

    The world’s entire food system is under attack - and Britain is most at risk, according to a new study
    Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

    Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

    Seoul's plastic surgery industry is booming thanks to the popularity of the K-Pop look
    From Mozart to Orson Welles: Creative geniuses who peaked too soon

    Creative geniuses who peaked too soon

    After the death of Sandy Wilson, 90, who wrote his only hit musical in his twenties, John Walsh wonders what it's like to peak too soon and go on to live a life more ordinary
    Caught in the crossfire of a cyber Cold War

    Caught in the crossfire of a cyber Cold War

    Fears are mounting that Vladimir Putin has instructed hackers to target banks like JP Morgan
    Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years

    Salomé: A head for seduction

    Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years. Now audiences can meet the Biblical femme fatale in two new stage and screen projects
    From Bram Stoker to Stanley Kubrick, the British Library's latest exhibition celebrates all things Gothic

    British Library celebrates all things Gothic

    Forthcoming exhibition Terror and Wonder: The Gothic Imagination will be the UK's largest ever celebration of Gothic literature
    The Hard Rock Café's owners are embroiled in a bitter legal dispute - but is the restaurant chain worth fighting for?

    Is the Hard Rock Café worth fighting for?

    The restaurant chain's owners are currently embroiled in a bitter legal dispute
    Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival

    In search of Caribbean soul food

    Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival
    11 best face powders

    11 best face powders

    Sweep away shiny skin with our pick of the best pressed and loose powder bases
    England vs Norway: Roy Hodgson's hands tied by exploding top flight

    Roy Hodgson's hands tied by exploding top flight

    Lack of Englishmen at leading Premier League clubs leaves manager hamstrung
    Angel Di Maria and Cristiano Ronaldo: A tale of two Manchester United No 7s

    Di Maria and Ronaldo: A tale of two Manchester United No 7s

    They both inherited the iconic shirt at Old Trafford, but the £59.7m new boy is joining a club in a very different state
    Israel-Gaza conflict: No victory for Israel despite weeks of death and devastation

    Robert Fisk: No victory for Israel despite weeks of devastation

    Palestinians have won: they are still in Gaza, and Hamas is still there
    Mary Beard writes character reference for Twitter troll who called her a 'slut'

    Unlikely friends: Mary Beard and the troll who called her a ‘filthy old slut’

    The Cambridge University classicist even wrote the student a character reference
    America’s new apartheid: Prosperous white districts are choosing to break away from black cities and go it alone

    America’s new apartheid

    Prosperous white districts are choosing to break away from black cities and go it alone