Splurging on a slice of pizza a week may not be a guilty pleasure after all. New research serves up a link between pizza and reduced cancer risk.
Researchers in Milan have found an association between regular pizza eating and a decreased risk of cancers of the digestive tract—including the mouth, throat, esophagus, colon and rectum.
Led by Silvano Gallus of the Istituto di Ricerche Farmacologiche “Mario Negri” in Milan, Italy, researchers evaluated the eating habits of more than 8,000 Italian hospital patients, 40 percent of whom were admitted for digestive tract or laryngeal cancer and 60 percent who were admitted for other conditions. Each person completed a standard questionnaire and a food frequency survey, which included a specific question about pizza.
By comparing the people with cancer to those who did not, the researchers found that the cancer-free group contained a greater proportion of regular pizza eaters. The so-called “regular eaters” ate one or more slices of pizza per week.
Study participants were also classified as occasional eaters if they consumed 1 to 3 portions of pizza per month, and the non-eaters ate less than one serving in a month.
In many instances, the non-pizza eaters were four times as likely to develop cancer than those who ate pizza once a week.
In the study, out of 1,225 patients with colon cancer, 503 were non-pizza eaters. Those who occasionally ate pizza numbered 473, and just 249 of those with colon cancer were regular pizza eaters.
An even greater difference occurred between those with oral and throat cancer. Of the 598 total cases, 310 were in patients who ate no pizza. The occasional eaters numbered 213, and only 75 regular pizza eaters had cancer of the throat.
Other factors considered when evaluating patients were age, sex, hospital admitted to, education, alcohol and tobacco use, total daily calories consumed, body mass index, and for colon and rectal cancer, a measure of physical activity.
The results are published in a recent issue of the International Journal of Cancer, the official journal of the International Union Against Cancer.
In it the authors write, "Even if the association is real, inference on specific components of pizza, macro or micronutrients remains difficult, since pizza may simply represent an aspecific indicator of Italian diet."
The results of this study somewhat contradict previous studies which found refined carbohydrates, like those in pizza dough, have a link with colorectal cancer. But since pizza also contains tomatoes and olive oil, which have been shown to be associated with reduced cancer risk, the authors suggest the benefits from eating pizza may lie in these toppings.
While the researchers generalized pizza eating with reduced cancer risk, they did not distinguish between which types of pizza or for how many years the study participants remained regular pizza eaters.
The researchers also note that the traditional Mediterranean diet, rich in olive oil and tomatoes, "could prevent 10 to 25 percent of several common cancers in developed western countries."
And they caution that assuming the cancer-fighting effect of pizza in the traditional Italian diet may not be applicable in other diets and populations.