Naked Science Forum

General Science => Question of the Week => Topic started by: IzzieC on 18/03/2019 16:11:24

Title: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: IzzieC on 18/03/2019 16:11:24

Aidan asks,

"Consuming orange carrots in high excess can turn your skin orange, because of the beta-carotene. What about purple carrots?"

What do you think?

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: Bored chemist on 18/03/2019 19:06:37

The most likely outcome is that it would turn your urine purple (or red or blue depending on pH)

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: evan_au on 18/03/2019 20:22:31

In some people, eating excess beets/beetroot will turn urine or feces purple.
https://en.wikipedia.org/wiki/Beeturia

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: Kryptid on 18/03/2019 20:39:18

It probably wouldn't. Orange carrots get their color from carotenoids whereas purple carrots get their color from anthocyanins. Anthocyanins are apparently metabolized and excreted rapidly from the body. Interestingly enough, purple carrots actually have more carotenoids than orange carrots, so you could well turn orange from eating too many of them instead.

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: Bored chemist on 18/03/2019 20:53:27

Quote from: evan_au on 18/03/2019 20:22:31

In some people, eating excess beets/beetroot will turn urine or feces purple.
https://en.wikipedia.org/wiki/Beeturia

Yes, but beets have a different set of colours to them.
https://en.wikipedia.org/wiki/Betalain
Rather than
https://en.wikipedia.org/wiki/Anthocyanin

The anthocyanins are more extensively metabolised, but some still gets into the urine.
(About 5% in this study)
https://www.ncbi.nlm.nih.gov/pubmed/16861803

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: syhprum on 18/03/2019 23:17:30

As a child I used to take Do Do tablets to relieve asthma I understand the active  ingredient was Ephedrine the tablets were orange and they turned my urine green (I knew they were working when that happened!)

Title: Re: QotW 19.03.18 - Would eating purple carrots turn you purple?
Post by: katieHaylor on 03/04/2019 09:25:53

This question has now been answered, and you can listen to it here: https://www.thenakedscientists.com/articles/questions/does-eating-purple-carrots-turn-you-purple (https://www.thenakedscientists.com/articles/questions/does-eating-purple-carrots-turn-you-purple)