What is daikon?
Daikon, a Japanese word that literally means “really big radish,” is an Asian radish with extremely large roots. The Sakurajima variety can weigh as much as 50 pounds (22 kg). Most daikon radishes weigh 1 to 2 1/2 pounds (500 g -1250 g) at full maturity. Daikon leaves may spread as much as 2 ft (60 cm) across. The leaves can be distinguished from the smaller spring radish types by their great notches and by their arrangement around in the root top in a rosette. Some varieties of daikon form a root shaped like a spinning top, but most are cylindrical.
Daikon radish does not contain beta-carotene, but eating daikon at the same meal increases absorption of beta-carotene from other foods. The absorption of beta-carotene is less than the amount that would be absorbed from a beta-carotene or mixed carotenoid supplement taken on an empty stomach, but more than the amount of beta-carotene that would be absorbed from the vegetable by itself. The pungent chemicals in daikon break open the protein-lined sacs in vegetables that contain beta-carotene, releasing it in the digestive tract. On the other hand, the fiber in daikon interferes with the absorption of pure beta-carotene from supplements. Eat daikon when you eat sweet potatoes, carrots, or dark leafy greens, but avoid daikon when you take mixed carotenoid supplements.
Daikon also is a a great quick detox food if you eat smoked or grilled meat or fish. The amino acid cysteine in the radish traps formaldehyde in the meat or fish to form thioproline, which by itself is a carcinogenic chemical. The form of thioproline made with the amino acids in daikon radish, however, never enters the body because it is excreted in the urine. Japanese nutritionists have found that eating daikon (or other Japanese vegetables) with cod increases the elimination of cancer-causing thiroproline over 15-fold.
Photo credit: By Ralf Roletschek (talk) - Fahrradtechnik auf fahrradmonteur.de (Own work) [GFDL 1.2 (http://www.gnu.org/licenses/old-licenses/fdl-1.2.html)], via Wikimedia Commons