New research has uncovered coffee’s significant, potential properties in lowering the risk of certain cancers, according to toxicologist and food-safety expert Eileen Madden, Ph.D. in a presentation at Coffee and Your Health: Surprising Findings, a symposium for science writers held today at the New York Academy of Sciences.
Dr. Madden also notes that these newer findings tend to support a growing, wider scientific consensus on coffee’s predominately healthful properties, in a major turnaround from old conclusions reached by flawed methodologies. According to Dr. Madden, “When all of the available research is evaluated together it seems to suggest that coffee is associated with a decreased risk of colon cancer.”
A paper just published by researchers at the reknowned Mario Negri Institute in Milan reviews all the scientific research on coffee and colorectal cancer to date, and concludes that coffee consumption not only does not have a causal link to cancer, but that regular coffee drinking seems to be related to a decreased risk of colon cancer as great as 25%.The toxicologist told the science writers that there could be several reasons for this beneficial effect: “One reason could be that coffee has a laxative effect, which means that waste, which can contain dangerous substances, is in contact with the lining of the colon for a shorter period of time. Another possible reason is the antioxidant compounds in coffee. Coffee also increases the activity of enzymes which are important in detoxification. The polyphenols in coffee, moreover, are thought to be effective scavengers of mutagenic compounds. Another idea that has been proposed is that coffee might reduce the amount of bile acids, which are associated with an increased risk of colon cancer.”
Dr. Madden described research done in Boston in the early 1970s by a group who looked at hospitalized patients with pancreatic cancer. She explained, “These patients were compared with controls, who also happened to be patients in the hospital, but with illnesses other than pancreatic cancer – cardiac problems, stomach disorders – problems for which they may have been advised to restrict coffee intake. These controls did not drink as much coffee as the patients with pancreatic cancer, most likely because their physicians advised them against doing so. So it was assumed that, because the patients with pancreatic cancer drank more coffee than the controls did, that the coffee somehow contributed to the pancreatic cancer.”
There were a number of flaws in the study, Dr. Madden told the science writers, including the unfortunate fact that the pancreatic cancer patients died rather quickly, making it impossible to query them about their coffee drinking habits. “The reporting might not have been that good,” she noted, “which was unfortunate, since the study was widely covered in both the lay and medical press.”
investigators found no relationship between coffee drinking and pancreatic cancer
Questions were raised about the appropriateness of using hospital patients for the control group, because they were hospitalized for illnesses that may have required them to restrict their coffee intake. So, Dr. Madden said, “The researchers repeated the study, this time comparing pancreatic cancer patients with free-living controls.” This time the investigators found no relationship between coffee drinking and pancreatic cancer.
After that, other researchers studied the same question and none could confirm that drinking coffee led to pancreatic cancer. In fact, some investigations even suggested that coffee might have a protective action. Certainly a causal relationship with coffee was unlikely. There was information that the patients with pancreatic cancer tended to smoke, however, and smoking is believed to be a significant risk factor for pancreatic cancer. “So it became obvious that it was very important to factor in smoking when evaluating pancreatic cancer risk, since many individuals who consumed coffee heavily also smoked,” said Dr. Madden.
She concluded her presentation with this encouraging news: ” Coffee consumption fits into a very healthy diet, and if anything, may have a beneficial effect. Neither the American Cancer Society nor the National Cancer Institute considers coffee consumption to be a risk factor for developing cancer. Despite what you may read,” Dr. Madden advised, “if they don’t consider coffee a risk factor for cancer, why should anyone else?”
This article has been reproduced from CoffeeScience.org – http://coffeescience.org/media/anticancer