Does li hing powder pose cancer risk?
By Landis Lum
By Landis Lum
Q. I love li hing mui seed. I also buy the li hing powder and sprinkle it on various food items. My husband says to stop, or I will get cancer. Is there any truth to that?
A. Seems like most anyone growing up here gets the parental warning that eating too much li hing mui can cause cancer. What exactly does li hing contain? Plum extract, sugar, salt, licorice extract, artificial coloring such as FD&C Yellow #5 and Red #40, and often the sweetener aspartame. Current evidence does not show any link between aspartame and cancer risk. And though there have been problems with food colorings over the years, those that have been linked to cancer have been pulled off the market by the Food and Drug Administration.
But long-term ingestion of dried, smoked and salted foods does appear to be associated with stomach cancer. This cancer is higher in Japanese Americans and highest in Japan, China, Chile and Ireland.
Similarly, cancer of the pharynx and nose, especially common in Chinese living in the province of Guangdong and in the Inuits of Alaska, has been associated with consumption of salted fish. One theory is that nitrates in cured foods are changed into cancer-causing nitrites by bacteria in the stomach. A 1996 study from Leuven University in Belgium in 24 countries found that while nitrates and salt were associated with increased stomach cancer risk, the relationship was stronger for salt.
But does curing foods really increase stomach cancer risk? Curing refers to food preservation and flavoring processes, especially of meat or fish, by adding a combination of salt, sugar and either nitrate or nitrite. There's been a marked decrease in stomach cancers since the 1930s, when refrigerators came into widespread use. Refrigeration would not only have reduced the need for folks to cure their food but may also have led to less bacterial contamination of foods, reducing the production of cancer-causing nitrites by germs in the stomach. Furthermore, refrigeration also increases the proportion of fresh fruits and vegetables in the diet, which has likewise been associated with reduced stomach, pharynx, nose, and other cancers.
Therefore, it's not really clear whether it's the salt, nitrates, bacteria or a lower fruit and vegetable intake that really causes stomach cancer — it's perhaps all of the above. So I can't tell you for sure that you won't get cancer from all those li hing muis. Remember: The salt and sugar in those seeds also can increase blood pressure and tooth decay. So maybe mom and dad were right after all. As I tell my patients: Everything in moderation. And eat your fruit and vegetables!
Dr. Landis Lum is a family-practice physician for Kaiser Permanente and an associate clinical professor at the University of Hawai'i's John A. Burns School of Medicine. Send your questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; or write email@example.com. This column is not intended to provide medical advice.