What is a complete protein?

[vitalwheatgluten]

I've heard that "complete proteins" are a rarity in the plant kingdom.

 

I sometimes use a hemp protein powder that apparently has amounts of at least 19 or 20 of the 21 possible amino acids, including all of the essential ones that the human body can't create. I never hear hemp being a complete protein. In fact I only hear that about soy isolate and quinoa.

 

Assuming nutritiondata.com is accurate, I looked at a few things I like to eat:

 

~200 calories of cooked broccoli I ate tonight have about 13 or 14 grams of protein, with amounts of every amino acid except one called hydroxyproline, which I don't think is an essential one.

See: http://www.nutritiondata.com/facts/vegetables-and-vegetable-products/2357/2

 

~200 calories of cooked brown rice has 5 g of protein with each kind of amino acid

See: http://www.nutritiondata.com/facts/cereal-grains-and-pasta/5710/2

 

~200 calories of cooked quinoa has 8 g of protein, with each kind of amino acid

See: http://www.nutritiondata.com/facts/cereal-grains-and-pasta/10352/2

 

~200 calories of kidney beans or black beans, 15 g of protein, same thing

See: http://www.nutritiondata.com/facts/legumes-and-legume-products/4284/2 or http://www.nutritiondata.com/facts/legumes-and-legume-products/4297/2

 

And spinach: http://www.nutritiondata.com/facts/vegetables-and-vegetable-products/2627/2

 

And flaxseed, which even has this mysterious "hydroxyproline": http://www.nutritiondata.com/facts/nut-and-seed-products/3163/2

 

And so on....

 

Everything I've mentioned is the basis for a lot of my meals, especially dinner-type meals. Aren't all of these complete proteins? Or at least foods that don't really need to be complemented with anything because, at the very least, they have all the essential amino acids? Is there a certain amount of each amino acid that needs to be met for a food to be a "complete" protein?

 

Thanks for any and all help.

[strawberryriddick]

There's a certain amount of an amino acid that does need to be met to be considered "complete" or "adequate." The problem is, unless you're eating just ONE type of food and not enough of it, you're not going to be missing out on your protein anytime soon.

 

As for quinoa and soy being the only "complete" plant proteins you hear about, it's just due to lack of knowledge. The complete proteins I know off the top of my head are hemp, soy, quinoa, buckwheat, amaranth, and avocado. Hemp was argued on another thread, that the WHO doesn't consider it to be complete because it's deficient in some essential aminos...but does state that the deficiency applies to children 2-5 years of age.

[xjohanx]

Hemp was argued on another thread, that the WHO doesn't consider it to be complete because it's deficient in some essential aminos...but does state that the deficiency applies to children 2-5 years of age.

 

World health organization, FDA etc etc all pretty much agree as far as I know. And the numbers were for 2-5 year olds but I don't think that changes much over time..

[strawberryriddick]

Hemp was argued on another thread, that the WHO doesn't consider it to be complete because it's deficient in some essential aminos...but does state that the deficiency applies to children 2-5 years of age.

World health organization, FDA etc etc all pretty much agree as far as I know. And the numbers were for 2-5 year olds but I don't think that changes much over time..

Interestingly, it does. In doing that EAA profile thing for hemp, I noticed that two amino acids were repeatedly listed with "children" next to them...basically, those two aminos are only essential for children. I don't know what about the body changes that they're no longer essential or as essential.

[xjohanx]

Of the ones we discussed in the other thread no one was a semi eaa

[vitalwheatgluten]

There's a certain amount of an amino acid that does need to be met to be considered "complete" or "adequate." The problem is, unless you're eating just ONE type of food and not enough of it, you're not going to be missing out on your protein anytime soon.

 

As for quinoa and soy being the only "complete" plant proteins you hear about, it's just due to lack of knowledge. The complete proteins I know off the top of my head are hemp, soy, quinoa, buckwheat, amaranth, and avocado. Hemp was argued on another thread, that the WHO doesn't consider it to be complete because it's deficient in some essential aminos...but does state that the deficiency applies to children 2-5 years of age.

 

Thanks for the responses. Let's say I am eating one type of food, like hemp for example. And let's say it has low levels of 2 different kinds of amino acids. Why wouldn't eating a lot of hemp satisfy your needs since, by eating a lot of hemp, you'd be accumulating more of each amino acid. Does it have to do with ratios?

[seitan_man]

Avocado a complete protein?!? Surely not?

[cubby2112]

Avocado a complete protein?!? Surely not?

 

There are actually a lot of vegan foods that are complete and well-balanced proteins that are low in protein and/or calories, making their contribution to the amino acid pool very insignificant. Various leafy greens are very high quality proteins, but their calorie content is so low. I think several different kinds of fruit have rather good profiles, but are very low in total protein. Pumpkin seeds are incredibly high quality, but only 15-20% protein, which is at least better than many others.

[vegimator]

Pistachios, spirulina, most greens, many beans (black, white, garbanzo, winged, pinto...) all break 100 on nutritiondata but I don't know where they fall as far as digestibility.

[cubby2112]

Pistachios, spirulina, most greens, many beans (black, white, garbanzo, winged, pinto...) all break 100 on nutritiondata but I don't know where they fall as far as digestibility.

 

I'd be willing to bet that pistachios have great digestibility, and I know spirulina does. Greens are likely quite low. Beans have a PDCAAS of about 0.7, which takes into account digestibility.

[vegimator]

Ah, cool. Where'd you find the pdcaas for beans? I've pretty much only been able to find the ratings for soy and animal products.

[cubby2112]

I've seen a random bean here and there. Most are in the upper .6 range, like kidney beans here: http://en.allexperts.com/e/p/pd/pdcaas.htm

 

I think split peas usually rank around .72, and are rather high in protein compared to other legumes. They are basically second behind soy in protein quality and quantity. Lentils are of lower quality than most beans, but high protein quantity.

[vegimator]

What really interests me is the winged bean. They have a similar nutrition profile to soy. Also, the entire plant is edible and highly nutritious (the leaves, tuber and immature seeds in addition to beans). http://www.nutritiondata.com/facts/legumes-and-legume-products/4402/2

http://en.wikipedia.org/wiki/Winged_bean

 

The downside is that they're really hard to find commercially in the US though China developed a version that can grow in non-tropical climates and the seeds are available here in the states. Also, some people say they taste pretty bad.

[cubby2112]

Cool. I'd like to try them sometime. Black-eyed peas also have a great profile.

[strawberryriddick]

Thanks for the responses. Let's say I am eating one type of food, like hemp for example. And let's say it has low levels of 2 different kinds of amino acids. Why wouldn't eating a lot of hemp satisfy your needs since, by eating a lot of hemp, you'd be accumulating more of each amino acid. Does it have to do with ratios?

Well, sure, but it's not exactly going to be a good idea to focus on one protein. That's why the "incomplete protein" thing is kind of a pet peeve for me because basically saying that protein is "deficient" is to suggest that a person isn't eating a well-rounded diet.