Talk:Protein/Aragorn2 2005 04 24

From Wikipedia, the free encyclopedia

Hello, User:jag123, here are my replies to your recent posts on Talk:Protein.

I have since rewritten the paragraphs in question and made sure that POVs are discernible as POVs. In the following, unindented paragraphs are your words, and indented ones are mine.

I was more interested in references re: the minimum amount of proteins needed.

Is that better? It's not the WHO, but it's the UN and it seems rather detailed.

Here are some parts I find particularily interesting:

• This page states that human milk contains even less utilizable nitrogen than originally believed since about a fourth of it is non-protein nitrogen, and only 10-20% of that can be used to form protein in the infant's body: "The proportion of non-protein nitrogen (NPN) in human milk, about 20-27% of total nitrogen, is large as compared to most other species" ... "These have shown that about 10-20% of this nitrogen is utilizable.". To sum it up, that means that human milk has the lowest nitrogen content of all mammals, and a larger portion of that than in most species cannot be utilized for protein synthesis.
• Figure 12 of this page is also interesting. The two pillars to the right of each block indicate protein synthesis and protein breakdown, rsp.. You'll note that for any of the various protein intakes (0.36g/kg/d up to 2.07g/kg/d) protein synthesis overweighs breakdown, which means there is no loss of body protein. So 0.36g/kg/d is more than "maintenance level". For a 75kg man who eats 2500kcal/d, that would correspond to 27g of protein a day, at 4.3% of total calories. The average strict vegetarian in Western countries, however, consumes 14% protein calories, only slightly below the 17% of an omnivore.

The McDougall reference (hardly neutral, by the way)

What's neutral in your opinion? The official recommendations by the USFDA, which are almost twice that minimum established above? Still, they recommend a protein intake of only at least 8%, almost half your figure of up to 15%!

doesn't even reference the WHO, it just says they said so-and-so. In any event, I'll use the value you quote, 37g. According to reference [7], [1], someone would have to consume 12 cups of human milk to meet their protein requirement. That's just shy of 3kg.

The point of this link was primarily to display the absurdity of the "official" numbers from the USFDA. You'll note that in order to meet this recommendation, you'd have to ingest 20 cups of human milk a day, or 5kg. This, in turn, would leave you with too much food energy (by 40% if your daily energy requirements are 2500kcal!), though, so you'd gain fat in the attempt, in effect about 2.5kg of fatty tissue a month. In a year or two you'd look like a balloon.

Sure, that sounds like a lot, but it's not a big feat considering it's mostly water. As for the lettuce, according to [2], a head of lettuce (360g) gives me 5g of proteins. Sure, 22% of the calories come from protein, which sounds really nice, but only 1.4% of the total weight is protein.

More than in human milk, even by mass, I might add.

I'd have to eat 7 heads of lettuce per day to get the daily minimum of protein, and that would only give me 400 calories! Personally, I'd rather drink 3kg of milk. But that's besides the point.

This is funny - you say that drinking milk all day would be fine since it's mostly water, but in effect lettuce is over 90% water, too. On Thursday (IIRC) I performed a little self-experiment by eating nothing but a head of lettuce (with some oil, which you'll agree is devoid of protein) for breakfast. About an hour later I had an empty stomach and was very hungry again. This means I should be easily able to eat 7 heads of lettuce a day, though of course I find it wiser to just continue my "normal" diet of fruit, vegetables, grains, legumes, nuts, oil seeds and mushrooms, and products derived from them, just like most strict vegetarians. As for protein combining, I used to do this when becoming a SV only to realize a while later that it's an absolutely ridiculous waste of time! I didn't lose a grain of muscle since becoming a SV, and neither since abandoning all efforts of combining grains and legumes, or grains and buckwheat and this kind of things. I did lose fat, though, but I'll stop here because I don't have the time to list every positive effect on my health that shunning meat, fish, milk and eggs had.

As for the lack of food energy, some oil would surely fix the problem, but that's still besides the point. The point was that protein requirements can easily by eating a variety of plant foods. In effect, only certain fruit (e.g. apples at about 2.5%, and mangos at about 3% protein per kcal), as well as the "empty foods" mentioned before, fail to provide more than the 4.3% protein mentioned above.

Here is a link from the WHO. It does not mention protein recommendations, but they do say protein-energy malnutrition (emphasis mine). Protein-deficiency where energy needs are met is unknown even in developing countries.

You're right that eating only gummy bears would leave me malnutrionned. However, the important difference is that no one really claims, nor is it generally associated to be a good idea, to eat nothing but gummy bears.

Funny, I've never heard of a vegetarian who eats nothing but lettuce either, or claims that it was a good idea. Did you?

There are a lot of warnings regarding eating a lot of meat as well, but there is nothing even remotely similar regarding vegeterianism.

And why should it? Eating a lot of meat is known to cause a broad spectrum of diseases, for example gout, arthrosis, atherosclerosis, kidney failure, colon cancer (actually, even eating just a little meat drastically increases the risk of colon cancer) and hemochromatosis. I'm sure I forgot some.

If I decide to eat nothing but salad all day, I *will* become malnourished (unless I can eat seven heads a day, and even then it's extremely hypocaloric), and everyone will tell me "Eating vegetables is good. Keep it up".

No, if they hear that you eat nothing but salad (that is, lettuce), they'll tell you do get a more varied diet quickly! (see Straw man)

You pretty much prove the point when your take on my salad-only diet was "It's better than eating just gummy bears". If I was someone who used a lot of energy, like a physically-demanding job, then frankly, I'd rather eat only gummy bears.

I wonder how long you could keep up a physically-demanding job on a zero tryptophan diet. Anyway, in case you didn't notice, we're discussing the relative merits of caricatures. You came up with a caricature of a strict vegetarian who eats nothing but lettuce, and I came up with a caricature of an omnivore who eats nothing but gummy bears. It's both equally realistic.

At least my body wouldn't resort to breaking down muscle protein for energy.

From [3]: When an essential amino acid was given in insufficient amounts for approximately two days, all subjects complained bitterly of similar symptoms: a clear increase in nervous irritability, extreme fatigue, and a profound failure of appetite.

Obviously, this is worse than fasting, which does not cause fatigue or irritability for at least a week in a normal-weight person. The body obviously assumes that it gets sufficient EAAs since it gets sufficient calories, which turned out to be wrong under the artificial circumstances of this experiment.

Having said all that, how can you say that "careful to eat combiniations of food" is misleading or a half-truth? --jag123 07:32, 18 Apr 2005 (UTC)

That was not the wording. The points of contention were (for me, personally):

• incomplete proteins lack or contain only a very small proportion of one or more - "contain only a very small proportion" wrt to plant proteins is obviously total nonsense (I posted some PDCAAS before).
• When protein is listed on a nutrition label it only refers to the amount of complete proteins in the food - This was provably false.
• Animal-derived foods contain all of those amino acids, while plants are typically stronger in some acids than others. - The first part was misleading for one (e.g. gelatine, soy and sweet lupins don't fit into this scheme), the second part is just line noise because it's true for any food.
• Complete proteins can be made in an all vegan diet by eating a sufficient variety of foods and by getting enough calories. - The first part suggests that it is necessary to get protein only in the form of "complete" protein (which it is not, this only means that some more than the bare minimum needs be consumed). The second part has nothing to do with protein "completeness" as determined by the PDCAAS.
• It was once thought that in order to get the complete proteins vegans needed to do protein combining by getting all amino acids in the same meal (the most common example is eating beans with rice) but nutritionists now know that the benefits of protein combining can be achieved over a longer period of time. - Nutritionists (ok, those who actually bothered investigating the issue) now know that protein combining is all bollocks and redundant. I didn't state that as a fact, but I've made sure to point out that this is the POV of most SVs.
• Ovo-lacto vegetarians usually do not have this problem, since egg's white and cow's milk contain all essential amino acids. - This is once again misleading. For one, what about SVs that consume soy and sweet lupins? And second, what if "incomplete" protein, e.g. cereal protein overweighs? Then the total PDCAAS would be below one despite the consumption of milk and/or eggs. But of course, it's irrelevant since humans can thrive on "incomplete" protein.
• Protein deficiency can lead to symptoms such as fatigue, insulin resistance, hair loss, loss of hair pigment (hair that should be black becomes reddish), loss of muscle mass (proteins repair muscle tissue), low body temperature, and hormonal irregularities. Severe protein deficiency is fatal. This is all true, but, especially in combination with the previous paragraphs, it's also totally misleading, since it helps perpetuate the same old myth that SVs would die of protein deficiency or at least suffer hair loss, fatigue and so on as a consequence (which, obviously, they don't). I added , encountered only in times of famine, to clarify that a little.

Sure, spinach may have 30% proteins, but you'd neet to eat almost 1kg of it to meet the daily needs quoted above.

So what? Again, it's more than 90% water. At a German supermarket chain, a pound of deep-frozen chopped spinach is sold in packets roughly 6"x5" in size. It's quickly digested and not even half a meal. BTW, I don't recommend getting all your protein from spinach. You'd probably suffer a Vitamin K hypervitaminosis. It was an example of how a varied diet that may contain spinach or other protein-rich vegetables, can easily provide for human protein needs.

By contrast, one can (~110g) of tuna gives me 27g of protein.

So do 200g of tofu, along with a fraction of the mercury. Does it matter? Only if that was your only food in a day.

Unless you have studies (from a serious establishment [ie: not the McDougall newsletter]) regarding protein content of vegetarian diets, with a decent population size, then I don't know how you can say that it "simply isn't true".

Why should vegetarians be obliged to prove their innocence? (see Shifting the burden of proof)

Why don't you come up with any credible evidence that vegetarians are suffering from protein deficiency?

Back in high school, I knew a lot of girls who went vegetarian, and most of them did not eat nearly enough proteins,

That's interesting. How did you arrive at this diagnosis?

let alone calories, so I seriously question the veracity of your claims.

I claim that a reasonably varied plant-only diet which meets caloric demands provides enough protein. So, no, anorexics do not disprove my claim.

I have no doubt it may be unheard of, but that doesn't mean it doesn't happen. Getting scurvy is unheard of, but it did happen to a college student in the United States about two years ago.

I think this warrants a warning against scurvy in omnivores on the Vitamin C page, since no animal food contains decent levels of vitamin C. Oh, wait, The Straight Dope says that Eskimos got vitamin C from the skin of beluga whales, also called "muktuk". How many US-Americans eat muktuk on a regular basis? Do you happen to know any studies regarding that?

The next consequence would be to warn against scurvy in strict vegetarians that consume non-sprouted cereal grains and legumes, since these also contain little vitamin C.

We could even invent "arguments" like "But if I was a strict vegetarian and ate nothing but white bread, wouldn't I begin to suffer from scurvy?"

I don't see this as a pursuit of NPOV.

Yes, because the article's (previous) POV matches your POV, which is that humans had protein requirements (I take your figure of up to 15% of calories as a minimum) comparable to that of canines (I've seen recommendations of "at least 15% protein" for adult dogs).

You seem to want to add that eating too much proteins is bad to counterbalance the supposedly "non-neutral" claim that vegetarians should be careful to eat appropriate combinations of food.

Vegetarians, no, everyone should eat a variety of foods, but there is no need to combine proteins.

So far though, regarding your points, all I've seen is that "it's simply unheard of" for vegans to not have enough proteins, without anything to back it up. I know it's possible because I've met many vegetarians/vegans who weren't eating right at all, and wouldn't have to look very far to find more.

How did they suffer from protein deficiency? What did they eat and what symptoms did they display? Pray, tell!

Much as the case is here, it's nigh impossible to say anything bad about it, or even suggest improvements, because if it's green and it grows in dirt, then it's just got to be good.

You are the first to claim that in this discussion (another straw man).

By the way, I accepted the 37g of proteins because a higher value wasn't necessary, but personally, I find this extremely low.

It's almost twice the minimum as established through experimentation!

For all I know, that figure could be the minimum protein intake to basically survive.

The 20g figure is the figure where protein deficiency symptoms ceased in Dr. Rose's experiments.

I'd rather stick with the 10-15% of total calorie intake that is recommended.

100.000.000 lemmings can't be wrong?

Although there was some talk about amino acids, there was nothing about lysine, which is the limiting AA in human diet, and especially a concern in vegetarian diets.

Lysine is not the limiting AA in "human diet". Every kind of food has its own limiting AA. Legumes and buckwheat oversupply lysine, and it still doesn't matter.

Unfortunately, I don't have a lot of time to research all of this right now, but there isn't a shadow of doubt in my mind that many vegetarians out there don't eat right.

Doubtless - there are. Protein deficiency is probably not one of their problems, though. Many, having been conned into the protein myth, consume too much tofu and soy milk.

Don't assume that every vegetarian out there knows the difference between an amino acid and battery acid.

It's unnecessary to know about these things if a variety of plant foods are eaten and energy requirements are met. Whether you're a vegetarian or not.

It seems you want to remove the statement because *some* vegans who actually know what they are doing eat right.

This is so hilarious. I feel with you since I used to believe in the same fairy tales, but I've actually tried it myself and performed a lot of research, and protein just isn't an issue! THERE IS NO NEED TO BE AWARE OF PROTEIN COMBINING!

That's like saying Westerners should continue to eat junk food because some of them do, and they are thin. --jag123 02:30, 19 Apr 2005 (UTC)

No, it's more like you saying that tomatoes cause BSE without any data to back it up.

If you tell me you eat a salad for lunch five times a week, and pasta, rice or can of baked beans for dinner, you're barely ingesting at most (with the beans) 40g of protein daily. You don't need a lab or sophisticated equipment to calculate the protein content, just a little mental math.

Well, my mental math tells me that a bowl of salad and a can of baked beans don't even add up to 600kcal! Pasta is made from durum wheat, which at 14% is high in protein.

Maybe you haven't noticed, but 10-15% of calorie = protein is often stated (I won't say established) and I have found the warning in many places, including a federal health agency.

Which is an argument from authority. Or do you care to provide the empirical data (sic) that these recommendations ought to be derived from?

The latter is true, but an omnivore is benefiting from macro-concentration, unlike the vegetarian.

What the hell is "macro-concentration" supposed to mean, and why don't vegetarians "benefit" from it?

You want to remove it because there are no epidemiological studies, fine, but that's really weak

Yes. Removing a claim because there's no evidence for it - how weak, indeed.

When was PDCAAS discussed? I see a statement that soy and sweet lupine have a PDCAAS of 1 with "this" mistake corrected (of course, no reference for the mistake). So what if if soy and sweet lupine have a PDCAAS of 1? Does every vegan consume 37g of soy protein or lupin every day?

The UN figures aren't specific to protein composition. That is, they already contain substantial leeway for a PDCAAS of below one. The WHO recommendation is actually twice the requirement I established above. So your question should be "does every (50kg) vegan consume 18g of not necessarily complete protein a day"? Let's say our hypothetical vegan ate nothing but rice, at about 8% protein and a PDCAAS of 0.5. At 1650kcal that would mean 33g of protein a day. So unless the requirements were derived from examining a diet (in a developing country!) with a total PDCAAS of at least 92%, that vegan would get enough protein according to the UN's figures.

Besides, that statement does show that some vegans do have marginal protein intakes, which, to me, only supports leaving the notice in the article.

Marginal according to the inflated official recommendations (USFDA or worse).

Calculating protein requirements for a high school girl who weights 110 pounds with a sedentary lifestyle is not a worst case example, it's a best-case example.

How do you arrive at this conclusion?

This is a worst case example: 80kg male who needs 3500-4000 kcal/day. That's 60g of protein, according to the FAO/WHO and 88g if we use the 10% of calorie figure.

The 10% figure is ridiculously inflated. At 4000kcal/day, eating only rice, you'd arrive at 80g protein. According to the UN figures, nitrogen balance is reached at 28.8g daily protein intake for an 80kg man. The UN figures assume a BV of about 0.6 to 0.7, which means ca. 20g complete protein. Rice has a BV of ca. 0.5, which means 40g complete protein. Seems to me the danger of a kidney overload is very real. ;-p

(I use tofu because soy protein has a PDCAAS of 1.)

The USFDA and your imaginary 10% figure don't mention no freaking PDCAAS.

To be part of the group of veg. in which protein deficiency is unheard of,

Only if protein deficiency was defined as "less than whatever specious claims are made about people's protein requirements".

For me to get enough proteins from a veg. diet, I'd have to actually sit down and seriously research thngs to determine what meals to prepare to suit my needs.

Yes, that's what I thought (and did), too, before actually trying it.

So why is it so hard for you to accept that it's possible for a vegetarian to not eat enough protein?

It's possible for vegetarians. It's possible for omnivores. What you failed to show was actual cases.

I should be kept in the dark because typical vegans (who probably have more insight on their diet than I, or are less active) appear to meet or exceed requirements? How is that a better scenario for me?

That's a good point, and I think it's best solved the way I did it - by keeping the POVs, but making sure that everyone sees that they're controversial.

Perhaps the article should include more information on when and why this might be a concern.

Indeed. Vegetarianism is not amongst. Famine and alcoholism come to mind.

Nutrition care professionals should be aware that protein needs might be higher than the RDA in vegetarians,

Sheesh. Goes to show that even the ADA doesn't know it better.

Let's recapitulate:

1. The UN figures (see the last diagram) give a 0.36g/kg/d requirement at a total dietary BV of only about 0.6 to 0.7.
2. The USFDA recommends a minimum about 2.3 times that (about 0.84g/kg/d if we use the 63g for an adult man figure, with a normal weight of ca. 75kg), for undisclosed reasons.
3. And now "nutrition care professionals" (sic) say that vegetarians' needs might be higher than the RDA without even considering how the RDA was actually established.

Sure, it's an interesting proposition, albeit not a very logical one.

As a final point - spent enough time on this answer already, but, well, I learned more interesting things about protein requirements - I found your "80kg male comment" highly refreshing, because, well, I happen to be a lean 6', 90kg male. And at 18" upper arm circumference left and right, after not having consumed animal protein in almost 6 months, I'm not aware of any "protein deficiency" of mine, thank you, even though I get a lot of my calories from fruit and fruit juices, as well as some candy and vegetable oil. I eat pulses and soy products on an irregular base. So you can surely understand I find that protein hype-thingy rather amusing.

Best regards, Aragorn2 20:52, 24 Apr 2005 (UTC)

PS: I donated blood recently and had a normal hemoglobin count. Just in case you wanted to come up with more myths about SVs.