Eating carrots during pregnancy makes babies happy in the womb, according to a new British study.
Mums to be change the mood of their unborn infants by what they have for breakfast, lunch and dinner.
Scientists recorded the first direct evidence of unborn infants reacting differently to various smells and tastes by looking at their facial expressions.
An analysis of 4D ultrasound scans of 100 pregnant women showed how foetuses responded after being exposed to flavours from different foods.
While carrots caused developing foetuses to ‘laugh’, kale, seemed to have the opposite effect, bringing them to ‘tears’.
‘A number of studies have suggested babies can taste and smell in the womb, but they are based on post-birth outcomes while our study is the first to see these reactions prior to birth,’ said lead author Beyza Ustun, a PhD student at Durham University.
‘As a result, we think this repeated exposure to flavours before birth could help to establish food preferences post-birth, which could be important when thinking about messaging around healthy eating and the potential for avoiding “food-fussiness” when weaning,’
The international team studied how the foetuses behaved just a short time after ingestion by the mothers.
Those exposed to carrot or kale showed more ‘laughter-face’ or ‘cry-face’ responses, explained Ustun.
The findings published in the journal Psychological Science sheds fresh light on the development of human taste and smell receptors.
Humans experience flavour through a combination of taste and smell. In foetuses, this may happen through inhaling and swallowing the amniotic fluid that surrounds it.
What pregnant women eat might also influence babies’ preferences after birth and help establish an appetite for fruits and vegetables.
‘Previous research conducted in my lab has suggested 4D ultrasound scans are a way of monitoring foetal reactions to understand how they respond to maternal health behaviours such as smoking, and their mental health including stress, depression and anxiety,’ said the study’s co-author Professor Nadja Reissland.
‘This latest study could have important implications for understanding the earliest evidence for foetal abilities to sense and discriminate different flavours and smells from the foods ingested by their mothers,’
The mothers, aged 18 to 40, were scanned after 32 and 36 weeks of pregnancy. They were given a single capsule containing about 400mg of carrot or kale powder around 20 minutes before the scan.
It was the only thing they consumed for at least an hour. The women also did not eat or drink anything else containing carrot or kale that day.
Facial reactions of the foetuses showed that exposure to just a small amount of carrot or kale was enough to stimulate a reaction, compared with foetuses not exposed to either.
‘Looking at foetuses’ facial reactions we can assume a range of chemical stimuli pass through maternal diet into the foetal environment,’ said Prof Benoist Schaal, another co-author on the study.
‘This could have important implications for our understanding of the development of our taste and smell receptors, and related perception and memory,’
The results might also help with information given to mothers about the importance of taste and healthy diets during pregnancy.
Researchers have now begun a follow-up study with the same babies post-birth to see if the influence of flavours they experienced in the womb affects their acceptance of different foods.
‘In other words, exposing the foetus to less “liked” flavours, such as kale, might mean they get used to those flavours in the womb,’ said Prof Jackie Blissett, another co-author on the study.
‘The next step is to examine whether foetuses show less “negative” responses to these flavours over time, resulting in greater acceptance of those flavours when babies first taste them outside of the womb,’