Can we learn to love our greens? UK primary school children may have found the answer

It’s great to see our young scientists already making an impact on the scientific world and with the help of our partners we have been able to show school children that their work and participation matters.Helen Foulkes, Creative Director of BBC Learning
Date: 31.01.2017     Last updated: 31.01.2017 at 12.16
As part of BBC Learning's Terrific Scientific campaign, young scientists have been eating kale every day in an effort to prove that there may be a reason as to why some people don't enjoy their green vegetables.

In partnership with Coventry University, school children aged 9-11 have been taking part in an exposure test and using blue food dye, a piece of card, a magnifying glass and bags of kale to find out what affects our ability to learn to love vegetables.

Children were separated into two groups; half were asked to eat a piece of kale every day over a 15 day period, whilst the other half ate raisins. The study found that the majority of those who ate kale everyday liked it more by the end of the test; however there was a select group who remained adverse to the taste. When delving deeper into this, the young scientists found that those who still disliked kale had more fungiform papillae (which carry our taste buds) on their tongue. These children were identified as supertasters.

Approximately 25% of the UK population may be super tasters and this makes them a lot more sensitive to strong tasting food such as Brussels sprouts, bitter coffee and grapefruits. If this is the case you may need to persevere for longer with strong tasting green vegetables such as kale before you start to enjoy them. 50% of the population are tasters meaning they are likely to try most food but may have a few they dislike whilst the remaining 25% are non-tasters and may require more salt, spice and condiments than others to prevent food from tasting bland.

This exposure test is part of Terrific Scientific, BBC Learning’s 18 month, UK-wide campaign to bring practical science into the classroom and into our homes. Focusing on 10 investigations the campaign will work in partnership with organisations from the world of science and a few famous faces. Aimed at upper primary school level, Terrific Scientific will help deliver the objectives of the science curricula for 9-11 year olds across the UK. So far over 8000 classes and almost 4000 schools have signed up to take part in the campaign and BBC Learning, in partnership with Wellcome, have sent out science boxes to 21,000 primary schools across the UK to encourage them to get involved in Terrific Scientific.

Jackie Blissett, professor in health behaviour and change at Coventry University, says: "It’s been wonderful to work with these young scientists, and they’ve helped shed some light on one of the great mysteries: why some of us might not like our Brussels sprouts! BBC Learning’s Terrific Scientific campaign is a fantastic way to engage youngsters in an interactive experiment which makes the learning experiment much more fun."

Helen Foulkes, Creative Director of BBC Learning says: "Terrific Scientific is already helping children, parents and teachers to get excited about science. It’s great to see our young scientists already making an impact on the scientific world and with the help of our partners we have been able to show school children that their work and participation matters."

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Pictured: Liz Bonnin and primary school children doing the taste test at the Terrific Scientific launch

What was the aim of the exposure study?

The aim of the exposure study was to see if children aged 9-11 could learn to like kale (a bitter-tasting food that lots of people dislike) by trying a little piece of it every day for three weeks.

The study also aimed to find out whether taster status affected how long it took children to learn to love, or at least put up with, eating bitter food.

Although there has been previous work on exposure studies with children, this is the first time the role of fungiform papillae density has been examined in relation to children learning to like bitter vegetables in a school setting.

How was the exposure study conducted?

One hundred and seventy five children at four schools across the UK were split into two groups, an experimental group (who ate some kale every day) and a control group (who ate a raisin every day). Both group’s opinions of kale were noted on the first and last day of the study. On the last day, the taster status of each child was determined, and this was then compared to their opinion of kale before and after the 15 day exposure period.

It was really important that everything was exactly the same for both groups except for whether they tasted kale or raisins each day. Whether children would get kale or raisins every day was determined by tossing a coin as it would not have been a fair test if we had let people choose which group to be in. We had a control group eating raisins so we could be sure the effects we found were due to the kale exposure alone.

Schools involved in exposure study

Coventry University and Terrific Scientific worked together to take the Exposure study to four schools over a three week period:

  • Plymouth Grove Primary School, Manchester, England
  • St. Fagans C W Primary School, Cardiff, Wales
  • St. Saviour’s RC Primary School, Glasgow, Scotland
  • Hazelwood Integrated Primary School, Belfast, Northern Ireland

What did we find?

The exposure study found that children who ate kale every day had a significant improvement in their liking of kale over time, but the raisin (control) group didn’t show this improvement. This means we can almost certainly train our brains to like a food we didn’t much like before. It doesn’t, however, mean we will love this food, simply accept it or rate it as less hated than before exposure.

Another finding was that it might be a bit harder to learn to like a bitter food if you are a supertaster, and 15 days may not have been enough. It requires some further investigation.

It is worth noting that whether we begin to like a flavour is not just down to our taste buds – our brains are doing the work here. Learning to like the flavour of a food is due to a mixture of its taste, smell, and our brain learning the food is safe to eat.

What does the exposure study mean/how can we apply what we have learned?

So here is the good news for parents… you CAN train taste buds to like new foods! If your child is a bit of a fussy eater, or in fact, a supertaster, don’t be disheartened! This simply means it may take your children a little bit longer than others to get used to new foods, so don’t give up! As long as you give them a little bit often, they will eventually become accustomed to the taste, and may even learn to love the food they hated.

What is a supertaster and who could be one?

A supertaster is a person who has lots of taste structures on the tongue called fungiform papillae. These structures contain our taste buds- so the more fungiform papillae you have, the more intensely you taste things. We can compare this to tasting things in neon where non-tasters, who have fewer fungiform papillae, taste in pastel.

It is often the case that supertasters don’t like foods with strong flavours, such as bitter green vegetables, grapefruit, coffee, olives, blue cheese, or hot and spicy foods that contain chilli or coriander. So if you find that you do not like a lot of these, you might be a supertaster, but you will have to carry out our test to find out!

The scientific literature suggests that 25% of the population are non-tasters, 50% are tasters and 25% are supertasters.

Previous studies have, however, shown that several factors could affect these proportions. Things like gender and ethnicity have been shown to affect tasting ability, with females and those with a South American background more likely to be supertasters.