Let's talk about red meat. Its definition is a bit vague, according to licensed nutritionist Monica Reinagel in a publication of the Academy of Nutrition and Dietetics. Most dietary studies categorize beef, veal, pork and lamb as "red meat." Simple enough.

But not really. Food scientists say red meat is red because it contains myoglobin - a protein in muscles that holds on to oxygen and iron. However, the dark meat of chicken and turkey - known as "white meat" - actually contain more myoglobin than veal or pork. And to further complicate things, dark-fleshed birds like emu and ostrich are sometimes identified as "red meat," says Reinagel.

Who cares if a meat is "red" or not? Because some research studies have associated the excess consumption of red meat (especially processed meats such as bacon and hot dogs) with an increased risk for certain diseases, including heart disease and cancer. Other studies have found no increased disease risk and even benefits with the consumption of red meat.

So herein lies the confusion … and the controversy. "Observational studies can detect a correlation between dietary patterns and health outcomes, but they cannot prove causation," states Reinagel. Think of it this way: I may observe a higher number of overweight people walking at the mall. That does not prove that I will become overweight if I walk at the mall. Other factors are obviously involved.

Theories why excess red meat might not be good for our health abound. Maybe it's due to too much saturated fat and cholesterol, which increases the risk for heart disease. Perhaps too much iron. Or maybe it's how we cook our meat. Any meat - red or white - that is char-broiled at high temperatures can release potentially cancer-causing compounds.

On the other hand, recent clinical studies - meaning they were actually tested on real people - have found that eating 3 to 4 ounces (moderate amounts) of lean beef each day helped enhance muscle development and strength in adults. Other recent studies found that moderate amounts of lean red meat could be reasonable additions to a heart-healthy diet. And don't forget that red meat is a nutrient-dense food - rich in protein, essential minerals, and B-vitamins.

So perhaps the "redness" of a meat matters less than the context of how much and how often I eat it. For instance, a (3-ounce) portion of pork tenderloin with fresh vegetables may affect my health much differently than two double-bacon burgers with cheese fries.

However you color it, we still have choices. Let's see where the evidence takes us.

(Barbara Quinn is a registered dietitian at the Community Hospital of the Monterey Peninsula. Email her at bquinn@chomp.org.)

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