Processed meats such as sausage, bacon, and cold cuts may increase the risk of pancreatic cancer, but only slightly, researchers found.
For every 50-gram serving of processed meat per day -- a couple of slices of ham, for instance -- relative risk of the disease rose by 19%, Susanna Larsson, PhD, of the Karolinska Institute in Stockholm, and colleagues reported online in the British Journal of Cancer.
Red meat also posed a 29% greater relative risk of pancreatic cancer to men, they found.
"Relative" may be a key word, here, however, since the risk of pancreatic cancer itself is low.
Action Points
- Explain that processed meats such as sausage, bacon, and cold cuts may increase the risk of pancreatic cancer, but that the risk of pancreatic cancer itself is small.
- Point out that red meat was associated with an almost 30% increased risk of pancreatic cancer in men but not in women.
Marji McCullough, ScD, RD, director of nutritional epidemiology for the American Cancer Society, who wasn't involved in the study, emphasized that the overall risks appear to be "modest," although they are "consistent with associations with red and processed meats seen with other other gastrointestinal cancers."
Several studies have shown a link between meat and stomach and colorectal cancers, but it's been unclear as to whether meat also affects pancreatic cancer risk.
So Larsson and colleagues conducted a meta-analysis of 11 studies totaling more than two million patients, 6,643 of whom had pancreatic cancer.
They found that eating at least 120 grams per day of red meat -- determined to be a "standard" serving -- was associated with a 13% increased relative risk of the disease, but it wasn't significant, and there was major heterogeneity between studies (P<0.001).
But when those findings were assessed by subgroup, that serving of red meat was associated with an almost 30% increased risk of pancreatic cancer in men (RR 1.29, 95% CI 1.08 to 1.53), and there wasn't significant heterogeneity between studies.
Red meat didn't raise the risk of pancreatic cancer in women, and the researchers said that men generally ate more red meat. That could mean there may be an association between the highest levels of red meat intake and pancreatic cancer risk, they noted.
Processed meat, on the other hand, was associated with a significant increase in pancreatic cancer risk all around. For every daily 50-gram standard serving, relative risk of the disease rose 19% (95% CI 1.04 to 1.36). Again, there wasn't significant heterogeneity between studies.
That increase is likely related to the nitrites and N-nitroso compounds found in processed meats, which have been shown to be carcinogenic and to induce pancreatic cancer in animal models, the researchers wrote.
However, they noted that the association was attenuated and lost significance in a sensitivity analysis that excluded just one of the studies.
Still, McCullough said the findings support American Cancer Society recommendations to limit the intake of red and processed meats to prevent cancer.
"This is more reason to follow a healthy diet, which aside from lowering the risk of cancer, also lowers the risk of heart disease and other diseases as well," she told .
She added that obesity and smoking are already established risk factors for pancreatic cancer.
Larsson and colleagues called for further prospective studies to confirm the findings, which were limited by the individual methodologies of the included studies, the lack of controlling for potential confounders such as weight and diabetes, and challenges in accurately measuring meat consumption.
Disclosures
The study was supported by the Swedish Cancer Foundation.
The researchers reported no conflicts of interest.
Primary Source
British Journal of Cancer
Larrson SC, Wolk A "Red and processed meat consumption and risk of pancreatic cancer: Meta-analysis of prospective studies" British J Cancer 2012; DOI:10.1038/bjc.2011.585.