While all cancer rates are generally very low in China, stomach cancer leaps out as a glaring exception. Figured at a population base of 100,000, the incidence in the U.S. is just 6.5, contrasted with a 90.9 incidence for China. What’s going on here?
Three main factors appear to be responsible for China’s high stomach cancer rates: preserved vegetables, stomach bacterial infections, and low blood levels of certain antioxidant nutrients. Interestingly, China Project scientists found that even in those people predisposed to the stomach cancers, a higher intake of plant foods led to fewer cancers.
In China, where refrigerators are rare, preserving vegetables by a combination of fermenting and salting is common. Fermentation per se may not be the problem as much as the way in which it is done. Bacteria and molds often intrude into the process triggering the sequence leading to cancer. Especially, stomachs chronically infected with the bacterium Helicobacter pylori one of the prime suspects in cases of stomach ulcers were found to be at increased risk for stomach cancers. This is particularly alarming because in the counties studied in China, H. pylori infection affected from 27 to 96% of the population.
On a more optimistic note, a strong protective factor for stomach cancer in China appears to be a high intake of fresh plant foods, and especially those with high levels of selenium and beta-carotene.