But the review, published in the Journal of the National Cancer Institute, doesn't call processed meats a cause of stomach cancer. There's not enough evidence for that, write the researchers.
They included Susanna Larsson, MSc. She works in Stockholm, Sweden, at the Karolinska Institute's nutrition epidemiology division.
Larsson and colleagues reviewed 15 studies on stomach cancer and processed meats, which included bacon, sausage, hot dogs, salami, ham, and smoked or cured meat.
The studies were published from 1966 through 2006 and came from Europe and North America and South America.
The studies included hundreds or, in some cases, thousands of people. They reported how much processed meat they ate.
Tracking Processed Meat Consumption
Categories of processed meat consumption varied widely, ranging from less than 1 gram per day to more than 56 daily grams.
The top of that range is about two servings of meats and beans on the U.S. Agriculture Department's "My Pyramid" food pyramid.
The studies didn't all use the same standards. So Larsson's team bundled all the data together and did their own analysis.
They found that higher intake of processed meats was associated with a greater risk of stomach cancer. "Findings were most consistent for bacon consumption," the researchers write.
Caution on Results
The researchers, who aren't giving any dietary advice, note that other factors may be involved.
For instance, the studies didn't adjust for infection with the Helicobacter pylori bacterium.
Stomach cancer is strongly linked to Helicobacter pylori infection, though most people with Helicobacter pylori infection don't get stomach cancer.
Also, some groups of people may be more vulnerable than others to stomach cancer due to factors that aren't yet understood, the researchers note.
SOURCES: Larsson, S. Journal of the National Cancer Institute, Aug. 2, 2006; vol 98: pp 1078-1087. Mypyramid.gov chart: "How Much Food From the Meat and Beans Group is Needed Daily?" News release, Journal of the National Cancer Institute.
By Miranda Hitti
Reviewed by Louise Chang, MD
© 2006, WebMD Inc. All rights reserved