Red as a Beet

Last night, I ate a hot-and-cold chicken salad with beets in it for dinner. Good thing I knew that it can cause a red-colored urine, or else, I would have panicked thinking I have hematuria. One thing that I discovered though is that it can also color your feces. I did not know that from clinical microscopy back in college nor in clinical pathology in medical school. It is a popular misconception that the color of red beetroot is due to a pigment known as anthocyanin which is the pigment in red cabbage. It is, in fact, due to a purple pigment betacyanin and a yellow pigment betaxanthin known collectively as betalins. Other breeds of beetroot which are not the usual deep red, such as 'Burpee's Golden' and 'Albina Vereduna', have a greater or lesser distribution of the two betalin pigments. Betacyanin in beetroot may cause red urine and feces in some people who are unable to break it down. The pigments are contained in cell vacuoles. Beetroot cells are quite unstable and will 'leak' when cut, heated, or when in contact with air or sunlight. This is why red beetroots leave a purple stain. Leaving the skin on when cooking, however, will maintain the integrity of the cells and therefore minimise leakage.