Street Food and Colon Cancer

Cancer on a stick?

Why these hot dogs are one street food you’ll want to avoid….

Chuanr stands like the one above are a common sight in the streets of Beijing, but those cheap hot dogs carry a high potential health cost: an increased risk of colon cancer.

Colon cancer has been on the rise in China, with as much as a 37% increase in incidence between 1988 and 2002 in some areas.  In Shanghai, one study showed the age-adjusted incidence rose by 100% between the period of 1972-77 and 1992-94.

That particular study also looked at Shanghaier’s diet patterns and found eating preserved foods was associated with increased risk of colon cancer, while fresh fruit was associated with decreased risk. The study authors hypothesized high levels of N-nitroso compounds (NOC’s or nitrites), which have been shown to be carcinogenic in animals and have been linked to cancer in humans, may be to blame.

Preserved foods, including the the hot dogs Beijinger’s love, use nitrite additives to keep food looking and tasting good. That’s why hot dogs have that nice pink or light brown color. Other preserved meats with high nitrite levels include bacon, breakfast sausage, ham steak/pork chops, ham, bologna, salami, and liverwurst. (Preserved vegetables also contain nitrites, check out my previous article on kimchi for more on this).

Preserved meat: good for long marches but not for long-term health

Scientists have explored the link between nitrites and cancer before, but one 2007 case-control study looked at the nitrites found in preserved meats specifically and their relationship with colorectal adenomas, a potential early indicator of colon cancer.  They divided their subject population into quartiles depending on how much preserved meats they ate. People in the highest quartile, who ate over 24 grams of preserved meats per day, had a 2x fold risk of colon cancer compared to those who consumed less than 3.7 grams per day.

Looking specifically at hot dogs, people who ate the highest amount of over 6.7 g/day also had a nearly 2-fold risk of colon cancer compared to people who ate no hot dogs.  The risk was also high even when they took into account all of the other meat in a person’s diet. That means that regardless of how much meat you consume, eating less than half a hot dog a day could significantly increase your risk of colon cancer!

What’s more, these small roasting stands likely use recycled oil, which is also problematic.

Although the studies on preserved meats and colon cancer are retrospective and use the case-control method to evaluate risk, I’d say the evidence is convincing enough to make those sizzling pink things on a stick look not so appetizing.   When you get the urge to snack steer clear of the hot dog guy and head to one of Beijing’s many fresh fruit stands instead.