Kimchi

History
Early forms of kimchi consisted mainly of salted greens. Chili peppers, now a standard ingredient in kimchi, were unknown in Korea until the early 17th century, when they were introduced from Japan or China, where they had been introduced by western traders. Traditionally, kimchi was fermented in pots buried in the ground, to serve as a winter subsistence staple when fresh vegetables were not available.

A cookbook from 1670 describes pickled mixtures of wild greens and pickled gourd melons, but makes no reference to the use of chilis. One historical record from the end of the 17th century describes eleven types of kimchi and thus kimchi utilizing red peppers would have been popularized some years after that (200 years, by one estimate). In addition, the introduction of Chinese cabbage probably did not occur until the 19th century ; before that, kimchi was made from indigenous vegetables.

Composition
The basic ingredient is usually a variety of Chinese cabbage called napa cabbage (배추, baechu) and/or white radish (무, mu), seasoned with chili pepper (빨간고추, ppalgangochu), garlic, scallion, ginger, salt, and sugar. Seafood-based seasoning is often added, such as oyster or anchovy-based broth (젓갈, jeotgal).

While the most popular type of kimchi is the napa cabbage variety, countless different types exist, including regional and seasonal varieties. Popular variants include kkakdugi (깍두기), based on cubed radish without cabbage, and oh-ee so-bae-gi (오이소배기), stuffed cucumber kimchi. Kkaennip (깻잎) kimchi features layers of perilla leaves marinated in soy sauce and other spices. The Kimchi Field Museum in Seoul has documented 187 historic and current varieties of kimchi.

Health effects
Kimchi was profiled by Health Magazine as one of the world's five "healthiest foods" for being rich in vitamins, aiding in digestion, and even possibly preventing cancer. The health properties of kimchi are due to a variety of factors. Most types of kimchi contain common ingredients like onions, garlic and peppers all of which have well-known health benefits. The main vegetable being made into kimchi also contributes to the overall nutritional value. Kimchi is rich in vitamin A, thiamine, riboflavin , calcium and iron and also has active and beneficial bacterial cultures of Lactobacilli which results in a higher lactic acid content in the final product than in yoghurt.

The low number of Severe Acute Respiratory Syndrome (SARS) cases in Korea is sometimes attributed to the Korean habit of eating large quantities of kimchi, although no definitive link has been established. There is some evidence that indicates that kimchi may be used to treat avian influenza in birds.

Some studies have linked its consumption to a reduced risk of gastric cancer, but other studies have linked consumption of certain types of kimchi (containing radish) to an increased cancer risk.The high nitrate salt concentrations in fermented Korean foods, such as kimchi and soybean pastes, have been suggested as a possible cause. However, talc, an irritant used in white rice in both countries has been posed as a possible alternative cause.