Monday, March 29, 2010

The Protein Issue

Over the course of the past six months or so my wife and I have been embarking on a culinary quest to remove all meat from our diets. Yes, that’s right we’ve been going vegetarian. Well pescetarian, actually, since we are still eating seafood and dairy sparingly. Admittedly, the wife has been much more religious about this than I have, but I tend to be wary about ordering vegetarian fare at typical American restaurants lest I be subjected to pay $11 for a shitty iceberg lettuce house salad every time we go out to eat. Anyway, whenever this topic is broached there is one question that tends to come up over and over again. No, it’s not “Where do you buy your patchouli, hippie?” The question that everyone asks (besides the obvious, “Why?”) is: “Well, where are you going to get your protein?” This very specific question about the nutritional content of food shows a lack of understanding of biology at the basic level that is propagated by marketing and one of the most ecologically harmful and powerful industries in the world, the cattle industry. Surely you can’t survive without beef. Can you? I can sum my response to that up in two words: fuck cows. I haven’t eaten beef (besides the odd burger or dog at the ballpark) for about 9 or 10 years now. I’ll address that in a later article. Sorry, I got off track there. Where were we? Oh, right. Where do hippies get their protein?

First, a little protein background education. Proteins are massively convoluted compounds that perform a host of different vital functions biologically. They are messengers, transporters, facilitators, and structural components. They are enzymes, antibodies, hormones, and literally thousands of other molecules that make life on the microscopic scale possible. At any one time there are more than 50,000 different proteins in our bodies. The DNA that every living organism on this planet possesses is essentially a construction manual for how to build these proteins. Each gene on our DNA codes for one specific protein. So when people say that someone has a gene for black, insect-like nipple hair, what they are actually saying is that they have a DNA sequence that codes for a protein (more likely a series of proteins) that causes the expression of their fly nipples through some very specific metabolic pathway (or convoluted series of pathways). Proteins are all made from complicated combinations of linked chains of 22 different amino acid building blocks. Titin, the largest known protein, consists of 34,350 amino acids linked together in an impossibly complicated mess. In contrast, the smallest known protein has only 20 linked amino acid chains. The amino acids themselves are relatively simple compounds containing carbon, hydrogen, oxygen, nitrogen and occasionally sulfur. I used to have all of their chemical structures memorized because some dipshyte professor thought that might some day be useful. I can safely say that I have never once in my career as a human ever recited to anyone for any reason the exact structure of a single amino acid chain. As such their memory has been erased by years of drinking and closed-head trauma, some of which I would love to inflict on that juice-bag professor. Our bodies can synthesize all but eight of these amino acids. The eight that we cannot make (leucine, isoleucine, valine, threonine, methionine, phenylalanine, tryptophan, and lysine) are called the essential amino acids, and we must get them from dietary sources.

When we eat anything that was once living (plant, animal, or otherwise) our digestive system breaks the proteins down into their prospective amino acid components. We are exceptionally good at this process of protein breakdown. The efficiency of this system ranges from 94% for the typical North American meaty diet to only as low as 88% for a North American dairy vegetarian (if you throw eggs into the dairy veg mix it goes up to 93%). Different types of foods contain different types of proteins, each with their own unique amino acid profile. This variation in amino acid profile means that there is a possibility that some amino acids may not be present in every food in the quantities necessary to construct the requisite proteins in the human body. Generally speaking, animal proteins tend to have more essential amino acids per gram of protein than plant protein. However, the body cannot distinguish the difference between the lysine that comes from pork and the lysine that comes from beans. They are chemically identical, and even slightly varying a vegetarian diet ensures that all of the essential amino acids are well represented. Anyone eating a well-balanced diet based on grains, seeds, nuts and vegetables will be consuming a mixture of proteins that complement one another naturally without requiring any planning. We wouldn’t be very good omnivores, evolutionarily speaking, if we couldn’t thrive by eating whatever happens to be available.

Eating replaces those proteins that we lose every day through feces, hair and nail growth, sweating, skin loss, etc. However, we recycle much more protein within our bodies than we loose externally. Every day the body reabsorbs and subsequently breaks down anywhere from 100 to 300 grams of protein internally. The resulting amino acids are used to make new proteins and keep the body’s amino acid pool (or blood reserves) topped off. The essential amino acids in this reserve have a lifetime of about six hours in the blood before they are burned, turned to fat or protein, or shat out. So this begs the question: how much protein do we actually need to eat to keep this amino acid reserve full?

Studies vary on the exact number for dietary protein replacement, but in the U.S. the average theoretical losses amount to about 0.34 g of protein per kg body weight per day. Safety margins are tacked on to this number to account for variations in the population and the digestibility and quality of protein consumed, so the final number ends up to be 0.8 g per kg of protein for an adult (RDA). For a 150 lb. person 54 g of protein need to be consumed daily according to U.S. standards; which is about three times more than what the body actually requires based on the theoretical losses above. Other countries vary in their requirement, but all are in the same ballpark. 54 g is about what a person would get if they ate nothing but three cups of rice and three cups of beans per day. The average non-vegetarian omnivore in North America consumes almost three times that amount (~130 g per day). The average ovolacto-vegetarian slugs down around 100 g per day, and the average vegan will get over 80 g. Yes, even vegans get much more protein than they actually need. The body doesn’t have a mechanism to store an excess of protein like it does for carbohydrates or fat. This is probably due to the fact that evolutionarily meat was an occasional score for humans in the wild, so we had to be very good at eating plants. In fact, the body can only process around 25 g of protein at any one time, and the rest is turned to fat and causes extra work for the kidneys. Just as a reference a single 12 ounce steak contains 70 g of protein. Moooo…

You may be saying to yourself, “Sure, that veggiesaurus BS may be OK for some pale, dope-smoking hippie, but I’m an oily Bo hunk and I need to eat meat and protein shakes to pack on muscle.” First of all, stop shaving your entire body. That’s just creepy. And second of all, even though I realize that your brain may not get worked out as much as your beefcake biceps, you should try to use it once in a while. I won’t go through an entire list of elite athletes that are vegans, like Carl Lewis and Stan Price (World Record bench press), but I will do a quick calculation. Suppose the fictitious muscle-headed reader wanted to pack on 2 lbs. of muscle in a month. That works out to be 226 g of protein after subtracting water weight. That’s about 7.5 g of “extra” protein which is required every day or 1 oz. of peanuts. It is much more important as an athlete to consume enough carbohydrates to keep your energy up and let the protein work itself out. In fact many athletes don’t get enough carbs because they stuff themselves full of protein, so the body inefficiently tries to burn the protein for energy instead of adding it as muscle because their glycogen reserves are low from not eating enough carbs. This isn’t generally a problem for vegetarians since a vegetarian diet is a good source of carbs. A vegetarian athlete will generally be able to pack as much muscle on as a non-vegetarian athlete assuming they consume enough calories. The same is true for pregnant women and children. Everybody knows this intuitively. During the largest growth period of our lives, infancy, we are strict vegetarians yet we have no problem packing on muscle. Also, think of all of the largest, most muscular land animals on the planet. Do they have any issues being vegetarian? Imagine a bull elk tearing into a T-bone steak to prepare for the rut. Gross.

More disease and death is caused in this world due to an excess of protein than due to a lack of protein. Consuming protein far in excess of what the body needs increases calcium excretion which increases osteoporosis risk and incidence of kidney stones. It is directly related to increases in kidney diseases, diseases of the digestive tract, cancer, heart disease, stroke, hypertension, gout, arthritis and laundry list of other diseases associated with the North American diet. What is considered excess? Some studies show that anything more than double the RDA is too much. So, while vegetarian diets are lower in protein than non-vegetarian diets this is in fact one of the benefits of such a diet. Whereas protein excess is a huge problem, protein deficiency is basically unheard of in the developed world. In the Third World horrible protein deficiencies do exist, but this is usually due to a lack of overall calories which eventually leads to starvation. Basically, the only way someone can end up with a protein deficiency in the U.S. is if they intentionally eat just grapes for a year or put themselves on some other weird ass restricted diet.

How did we get to a point where the word “protein” became synonymous with “meat”? The same way “Kleenex” came to mean “facial tissue” – marketing and the lobbying power of businesses. I am not going to get into food politics right now, but I will say that the folks in the animal protein industry are genius marketers and ruthless businessmen. They have essentially influenced an entire civilization into believing that they cannot survive without their products. This manifests itself in many ways, one of the most obvious being restaurant menus. Notice that there are entrees and there are sides. Often the word “entrée” is interchanged with “protein”. What are you going to have as your protein with that? Chicken? Beef? Pork? Tofu? Fish? Here’s a fun project to try next time you go out to eat: ask for your entrée on the side then watch the confusion begin. This not-so-subtle change in semantics has altered the whole psychology of how we eat. It has become so ingrained that people cannot imagine that not only is there ample protein in a strictly vegetarian diet, but that we must somehow supplement it with more. Just the other day I ordered a salad, and I asked if there was any meat on it. The answer I got was pretty typical and sadly predictable: “Oh, do you not want any protein on your salad?” Yeah, right. I would love to see you and the chef try to extract the protein from my salad. Can I have it on the side?

4 comments:

stephanie said...

I hope you feel better now.

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Fernando pannone Pessoa said...

un attimo di pausa e buona Pasqua a tutti. da fernando.

Dan said...

...and a good Passover to you as well, Fernando.