By: Eric Mittenthal
Having worked in the food industry for the last several years, I’ve grown accustomed to hearing about all the different foods and ingredients that are associated with cancer. It’s a topic that gets so much media attention, I’ve even contemplated writing a book called “Everything Causes Cancer” looking at all of the different research that “proves” one food or another is definitely associated with cancer.
This month, I was pleased to see that a couple of researchers had beaten me to the punch. In a study published in the American Journal of Clinical Nutrition (AJCN), Jonathan D. Schoenfeld and John P.A. Ioannidis examined the body of research on 50 of the most common cooking ingredients. They found that 40 of them had been the subject of a study tying the ingredient to a different level of cancer risk. Most importantly, they discovered that most of the reported associations were very weak, meaning the majority of claims you hear about different ingredients or foods causing cancer on the news are exaggerated, at best.
The implications of their study go beyond just the 50 ingredients examined. Much of the news we hear about food and cancer risks is based on epidemiological research. The studies often look at people’s self-reported habits over time and try to draw conclusions about health outcomes based on the data. Epidemiological data has value in helping to determine trends and associations that merit further research, but too often the published data exaggerates weak associations and then is reported as fact in the media without much in the way of a disclaimer about potential limits in study design or even that further study is needed.
AMI has a good resource on diet and cancer research helping to explain different types of studies and how to determine whether strong evidence exists. The International Food Information Council Foundation also has several resources related to communicating food and health research.
All of this brings us to one of the most commonly reported cancer connections, meat and cancer. Among the ingredients examined in the AJCN study were beef, pork, lamb, veal and bacon and the findings further support what the science has said for years that the meat and cancer association is weak. Among several studies examining this link, the best among them is the 2004 Harvard School of Public Health analysis involving more than 725,000 men and women and presented at the 2004 American Association for Cancer Research Conference. This study, “Meat and fat intake and colorectal cancer risk: A pooled analysis of 14 prospective studies,” showed no relationship between meat and colon cancer. In fact, the federally funded study shows that red meat and processed meat are not associated with colon cancer and uses what is considered perhaps the most reliable approach to analyzing relationships: pooling original data together and analyzing it.
Of course being an epidemiological study itself, the AJCN study shouldn’t be considered proof of anything, but it should serve as a reminder for people to think more critically the next time there’s a reported food and cancer connection. It also allows me to move on to my next book idea…”Everyone Who Eats Food Dies.”