Why aren’t there many naturally blue foods?

Question from Edgar Malone

There are good reasons why most natural foods aren’t blue. Partly it’s chemistry – many leafy vegetables, for instance, like lettuce and spinach, are green because they contain green-coloured chlorophyll, which is used in photosynthesis. Meat is often red because it contains blood and proteins that are partly made of iron, which is red-tinted and needed to carry oxygen around animals’ bodies.

Evolution also plays a part – fruit tends to be brightly coloured to attract animals to eat it and scatter the seeds inside, so there are few blue fruits because they wouldn’t stand out as well as those coloured red or orange.

Answered by Tom Lean for Brain Dump in How It Works issue 121.

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