Kids' dislike for vegetables caused by microbes in the mouth

If as a child, your parents forced broccoli on you against your will, you know that Brassica vegetables (including cauliflower, cabbage and brussel sprouts) are often unloved. A new study from the American Chemical Society reveals the science behind why some kids are so repulsed by eating these vegetables.

The research shows that as the unwanted vegetable touches the tongue, a chemical reaction occurs. An enzyme that exists within the microbiome of some people’s saliva reacts with the plant, creating a sulfurous odor. Needless to say, this is unpleasant. 

While previous research showed that adults have various levels of this enzyme within their mouths, the new study confirms that the same is true for children as well. Looking at the various levels of the enzyme, the scientists analyzed how this affects whether a child likes Brassica vegetables or not.

Using mass spectrometry, the scientists separated the active compounds causing the unpleasant taste reaction from steamed vegetables. Next, parent child pairs were tested for their reaction to the foul smelling compounds. The researchers mixed saliva with powdered cauliflower to see how much of the noxious chemical was produced by the interaction. There was great variability in how much of the smelly chemicals were produced by each saliva interaction.

Interestingly, in children, those whose saliva caused the worst reactions had the strongest dislike for Brassica vegetables. In adults, there was no cause and effect relationship between a dislike for Brassica and overactive saliva enzymes. The researchers also found that there was a lot in common between the saliva microbiome of a child and his or her parent. 

The study has real world relevance because in most western countries, vegetable consumption is below daily recommendations. This health faux pas may be partially due to the microbes living in our mouths.  

The research is published in the Journal of Agricultural and Food Chemistry.

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By Zach Fitzner, Earth.com Staff Writer