Thursday, June 20, 2013

Eating Red Meat

It's been a while since my last post. I wasn't happy with what I was doing with the blog, and I wanted to start actually writing about the nutrition side of things, but I was struggling to find the right inspiration. On June 17, an article entitled "Changes in Red Meat Consumption and Subsequent Risk of Type II Diabetes Mellitus" was published JAMA Internal Medicine, one of the journals of the American Medical Association, linking red meat consumption to increased risk of Type II Diabetes. Hello, inspiration. So without further ado...

One of the core concepts behind Paleo is high protein consumption. Legumes, soy, and dairy are problematic for a variety of reasons and are not supposed to be included, so protein is supposed to come from nuts, eggs, and to a large extent, meat. All kinds of meat are encouraged, and if it comes from the right source, even high fat content red meats are considered to be preferable.

So how, then, does the Paleo world take the news from the recent article about the link between Type II Diabetes Mellitus (T2DM)? The study used about 150,000 total participants who have been involved in other long-term research studies, and it followed them for four years to look at the effect of an increase or decrease in red meat consumption during that time. And they found a link between consumption of more red meat and an increased risk of T2DM.

This will not change how often I eat red meat. I’m sticking with my current beliefs about the value of this exceptionally rich nutrient source, and I will continue to eat it.

William Evans, head of the Muscle Metabolism Discovery Performance Unit at GlaxoSmithKline, agrees with me. In the same issue of JAMA, he wrote an editorial in which he presented an alternative explanation for the observed increase in T2DM risk: it’s not the protein type that’s the problem, it’s the type and amount of fat. Meanwhile, red meat is an incredible rich source of iron, and the most bioavailable form of iron – meaning that are bodies can process, digest, and use the type of iron found in red meat more easily than iron found in vegetable sources. (But don’t swap out your leafy greens for red meat. The greens are important, too.)

The iron in red meat is a major selling point for me. I grew up not eating red meat, because it had already been linked to increased cardiovascular risk and because my dad, previously vegetarian, would feel sick if he ate it. So it wasn’t part of what I was fed as a child. And I was fine, I was never anemic, but when I started donating blood, I discovered that my iron levels were low. Not anemic low, but low enough that if I WAS going to donate, they would drop low enough to make me anemic. I’m not remotely unusual because of this. It’s very common, especially in women. But I figure higher iron intake is only going to help, especially for my more intense training sessions. Iron is a critical component of hemoglobin, the molecules that carry oxygen around your body. That oxygen is important for effective use of stored energy, so iron is kind of important, and I can tell when my iron levels are low, because I feel more fatigued. So there’s no doubt that it’s important to consume enough iron, and animal sources are the most efficient ways to get it.

So why don’t I just eat other animals? It’s all about the quantity of nutrients available.

Let’s get back to the comment by Dr. Evans about saturated fat. Red meat, as it is defined in the article that links it to T2DM, is pork, beef, and lamb. But there’s a problem with this definition. Certain cuts of pork are very light and contain far less myoglobin (the primary iron source in muscle) than certain cuts of chicken, and tuna has up to three times the myoglobin content of beef. So what, really, were they measuring? Although we don’t have the full food frequency questionnaire that was used, the article states that they asked about unprocessed red meat as pork, beef, or lamb as a main dish; hamburger; or a mixed dish. They also asked about processed red meat including bacon, hot dogs, sausage, salami, bologna, and “other processed red meats”. What is obviously missing is any indication of the fat content or source of the meat.

You might be wondering what I mean by the source of the meat, which I’ve now mentioned twice. Simply put, it’s the question of whether the meat came from a feedlot farm or pasture-raised animals. Just as our diets and the amount of exercise we get affects our body compositions (body fat percentage, etc.), the way that your meat animals are raised affects what their bodies are composed of. Animals that are raised on feedlots are higher in saturated fat, higher in pro-inflammatory omega-6 fatty acids and lower in omega-3s, and may have additional non-natural body composition modifications… in addition to the horrendous environmental effects and antibiotic resistance problems that these feedlots create. So if you’re only eating red meat from feedlots, and you’re eating a lot of it, that’s a very different thing from eating pasture-raised, pasture-finished, organic meat. Yes, the other stuff is cheaper. But how much is your health worth?

Another thing that is mentioned in the article but not elaborated on is that they found that consumption of more processed red meat carried a greater risk increase that consumption of more unprocessed red meat. The article suggests that a table will be available with more information… but it’s not on the JAMA website at this time. The take home point, though, is that it’s the quality of the meat you’re eating that really matters. The recommendation I gave to my friend who mentioned the article to me is that eating more chicken is fine, but there is still value in red meat. Cut back on it, if you think that’s important, and use the money that you save in eating it less frequently to purchase higher quality red meats for the times when you do eat it. Look for leaner cuts and grass-fed or pasture-raised animals. Make sure those animals are coming from farms where they have space to move. If they aren’t as fat, you won’t be eating as much fat! (Note: not all fat is bad. But I like the fat I consume to be naturally acquired during the animal’s life, not artificially induced by keeping them stationary and feeding them unhealthy diets.)

1 comment:

  1. Cool Article. I have actually been vegetarian my whole life also so its interesting to learn about how our health is viewed much more differently than non-vegetarians.

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