Science Questions

Chameleon skin foods

Just as flamingoes are pink because they eat krill, penguins get the yellow spot on their face from the same source, would the same thing happen to humans? Carlos, Panama

We put this to Dr Stephen Juan, Ashley Montagu Fellow for Public Understanding of Human Sciences at the University of Sydney.

There are substances that can turn your skin different colours. One of the most famous ones is carotenemia which is when you eat too many carrots. Your skin can turn yellowish or orange. It’s a benign condition, doesn’t seem to be related to anything  but if you eat too many carrots the beta carotene builds up in your system and you turn into the colour of a carrot: first a little yellow and then a little orange. There was an interesting study in 2006 in Paediatric Dermatology by Royal Liverpool Hospital that showed that carotenemia can come from eating green beans as well. There are other vegetables as well like yams it’s been known to happen where the colour can change and some other fruits as well. Yes, you have to be very careful. Of course it’s going to show up in lighter skinned people first but it’ll happen to anybody. By the way, speaking of carrots the old question is what about carrots improving eyesight? Yes, carrots do improve the eyesight a little bit but only if you are vitamin A deficient to begin with.  

March 2009