Should Red and Processed Meats Be Removed from U.S. Dietary Guidelines? NO (from Family Practice News)

EDITORIAL Publication Date: March 1, 2005

A March 1, 2005 Family Practice News debate about whether to remove red meat from our diets included this "no" argument from ACSH's executive and medical director:

Scary headlines such as "Meat-Eaters Risk Cancer" predictably followed in the wake of the recent JAMA article entitled "Meat consumption and risk of colorectal cancer."

Let's look at what the study data really say -- and what they don't.

The authors -- from the American Cancer Society, Emory University, and the National Cancer Institute -- evaluated nutrition information going back over 20 years, obtained from questionnaires from almost 150,000 people, aged 50-74 years. Study participants gave this information in 1982 and again in 1992-1993, and they were followed until 2001.

The authors' assessment was that people in the highest segment of intake of red and processed meat in the 1992-1993 survey had an increased incidence of distal colon cancer, but this association was lost when other covariables were included in the analysis. (These covariables included smoking, body mass index, energy intake, alcohol use, and physical activity.)

For long-term consumers of large amounts of meat, those who were in the highest segment in both surveys had about a 50% higher risk of distal colon cancer, and they had a 43% increase in risk of rectal cancer.

Those who had higher meat intake in the later survey had a 71% higher risk of incident rectal cancer.

So, how relevant is the study for the American consumer -- is it as worrisome as it seems? I think not because:

The study is retrospective and observational, based on memory of dietary intakes and a questionnaire. These types of analyses are inherently weaker than prospective, controlled studies. The most egregious flaw involves data dredging: Many of the statistical associations lose power when confounders are taken into account.

The sheer quantity of meat consumed by the study patients is another issue subverting the authors' scary conclusions. In men, the amount of red and processed meat eaten by the group with increased risk was about 3 pounds weekly; women ate a bit less. This is far more meat than the federal dietary guidelines recommend, and much more than the large majority of Americans eat weekly.

My analysis: If you make red meat a part of a well-balanced dietary plan (according to the federal government's new Dietary Guidelines for Americans) and don't overindulge, you run no significantly increased risk of colon (or other forms of) cancer. Lean red meat is a high-quality, nutrition-dense food, and it is relatively low in calories.

Although this study may have some validity when restricted to those who indulge in long-term excessive meat consumption, it would be better to advise patients to pay attention to real health threats and not worry too much about eating meat.