29.03.2024

Picky eating gene mutation discovered by US scientists

Not finishing their greens really is down to a child’s genes and has nothing to do with their parents, according to new research. Two ‘picky eating’ mutations have been identified for the first time – one that puts youngsters off trying new food and the other that turns them into tea-time tearways.

The breakthrough could open the door to new ways of tackling the childhood obesity epidemic, according to researchers.

British scientists suggested last year that toddlers’ fussy eating habits are linked to genetics rather than being badly brought up. Now a US team has found DNA variants believed to be related to the perception of bitter taste among two to four year-olds.

New research has uncovered two gene mutations that could be the cause of fussy eating among children. File image used

One – known as TAS2R38 – was associated with limited dietary variety and the other called CA6 with being out-of-control during mealtimes.

Food fussiness – the tendency to be highly selective about the textures, taste and smell of foods a child is willing to eat – is often seen as a consequence of inadequate parenting.

But evidence is increasing that it’s a matter of nature and not nurture – with parents being largely blameless.

Nutritional scientist Natasha Cole said it’s not surprising children who are genetically ‘bitter-sensitive’ may be more likely to turn down Brussel sprouts or broccoli, for instance.

Doctoral student Ms Cole, a member of an obesity prevention program at Illinois University, hopes it can help identify the determinants of picky eating in early childhood.

She said: ‘For most children picky eating is a normal part of development. But for some children the behaviour is more worrisome.’

The genes control the chemosensory organs found in the tactile receptor systems

but it was not known if they were linked to children’s picky eating habits.

Ms Cole said for most preschool-age children fussy eating is just a normal part of growing up.

But for others insisting on only eating chicken nuggets at every meal for instance – or refusing to try something new – can lead to being over or under weight, illness or eating disorders later in life.

So information about breastfeeding and picky eating history was collected on 153 pre-schoolers from parents with DNA extracted from saliva samples.

One gene mutation – known as TAS2R38 – was associated with limited dietary variety and the other called CA6 with being out-of-control during mealtimes. File image used

Ms Cole and colleagues pinpointed the variants after selecting five particular genes related to the perception of taste.

They said other chemosensory factors such as odour, colour and texture may also affect eating behaviours as well.

Further studies are needed to see how children’s preferences are influenced by the look or smell of food.

Ms Cole is also interested in understanding how picky eating starts even in under 2s most research has focused on those older than this.

She said: ‘By two years children know how to eat and have pretty set habits.. There is a huge gap in the research when children transition from a milk-based diet to foods that the rest of the family eats.’

She said more than a fifth (22%) of under 2s are perceived as picky eaters by their parents.

Surprisingly she also found each additional month of the child’s age was associated with an increase in food fussiness.

Ms Cole said: ‘So a child could go from rarely being a picky eater to being a frequent picky eater in less than a year.’

Leading up to the genes study published in the Journal of Nutrigenetics and Nutrigenomics her team identified common characteristics of picky 2 to 4 year-olds and divided them into distinct groups.

Further research looked at how parenting styles may affect the behaviour and if children exhibit it both at home and in childcare.

Food scientist Prof Soo-Yeun Lee said: ‘This has kind of been an evolution of the research, seeing an interaction rather than just seeing the child as on its own, which, when we first started trying to define a picky eater, we were just looking at the child.

‘As we were moving into different parts of the research we realised it’s not just the child – it’s the caregiver and the environment as well.

‘Natasha is actually taking a deeper look at the child and genetic predisposition. She is looking at sensory taste genes and also at some of the behavioural genes that have been highlighted in the literature.

‘She has been looking at the whole field of picky eating research and classifying it based on ‘nature vs. nurture.’ Nature is the genetic disposition and nurture is the environment and the caregivers.’

She said the idea is based on an orchid/dandelion hypothesis. Prof Lee explained: ‘There are some genes – the behavioural genes – that make the child more prone and more sensitive to being more behaviourally problematic when external influences are present that may not work out their way.

‘That’s the orchid concept. This may be a sensitive child who may not be as resilient with negative feedback or negative mealtime strategies given by parents, versus a dandelion child who is very robust and resistant to whatever, nurture or not, is given to them.

‘There is that fine line, and it’s not just the nurture, the environment, that’s influencing that, but it’s the child’s susceptibility to the environmental cues as well.’

A year ago University College London researchers examined the eating habits of more than 1,900 pairs of twins and found they were more influenced by genes than upbringing.

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