Amino Acids and Complete Proteins

Getting All Essential Amino Acids As A Vegetarian

The most important thing to be aware of regarding protein in vegan diets is that you need to get enough of the amino acid lysine. Make sure you read the section on lysine and check out the high-lysine foods. Beyond that, there is evidence that erring on the side of more protein (1.0 to 1.1 grams of protein per kg of healthy body weight per day for adults) is a good idea, and especially for people 60 years and older.  If you are a vegetarian, you want to ensure you're acquiring enough protein through your diet while avoiding meats. What you really need in your diet, though, is essential amino acids. These building blocks of protein molecules are readily available in most foods, and it's actually difficult to follow a well-balanced vegetarian diet without consuming more than enough essential amino acids to maintain optimal health. The key phrase here is "well-balanced."

To understand how a vegetarian diet can adequately supply sufficient protein, it is important to know how proteins function in the body, and how the body manufactures them.

What Do Proteins Do?

Proteins are essential to nearly every bodily system. Proteins provide buildings blocks for:

  • Enzymes, which help with digestion
  • Hormones, which regulate growth and many bodily systems
  • Muscle, skin and other support tissue
  • The immune system

Protein, then, is essential to a healthy diet. However, a diet centered on animal protein sources often provides more protein than the body needs. In fact, a heavy protein diet can be toxic.  What the body truly needs to maintain optimum nutrition is a reliable supply of amino acids, the building blocks of protein.

Amino Acids - a Primer

Proteins are built from building blocks called amino acids. There are eight essential amino acids, referred to as essential because they cannot be manufactured by the body. A ninth amino acid is often included, as well, though this ninth amino acid is more necessary for children than for adults.

Most foods contain amino acids. Not all foods contain whole proteins. Animal-based foods such as meat, eggs or dairy, do contain whole proteins--one reason why we tend to assume they are the best forms of protein. However, plant-based foods contain high-quality amino acids that the body can use to create proteins. If one kind of food, such as beans or vegetables, does not contain a certain amino acid, that gap is likely to be filled in with amino acids available in grains, nuts or seeds.

Protein is important for maintaining muscle and bone mass, for keeping the immune system strong, and to prevent fatigue.

People not familiar with vegan nutrition often assume it is terribly hard to get enough protein on a vegan diet, and that's if they even think there is any protein in plant foods at all (how they think vegans survive is an interesting question, though many of them probably don't think we do). On the other hand, once "educated", most vegans have the diametrically opposite view, considering it impossible for someone not to get enough protein on a vegan diet.

The truth lies somewhere in the middle. It is easy to get enough protein on a vegan diet if you eat multiple servings of high-lysine foods (legumes, seitan, amaranth, quinoa, pistachios, and pumpkin seeds) each day. But there are many vegans who are probably not eating enough high-lysine foods.

Legumes include beans (garbanzo, kidney, pinto, etc.) and their products (falafel, hummus, refried, etc.), peas (green, split, black-eyed, etc.), lentils, and peanuts.

Vegans who do not eat enough calories to maintain their weight also need to pay special attention to making sure they are getting enough protein.

The reader needs to understand the importance of eating a wide variety of foods and NOT just stick to a few simple meals.  By eating a healthy whole food plant based diet, one can easily provide the body with the necessary amino acids it requires.   

Protein is important for maintaining muscle and bone mass, for keeping the immune system strong, and to prevent fatigue.

People not familiar with vegan nutrition often assume it is terribly hard to get enough protein on a vegan diet, and that's if they even think there is any protein in plant foods at all (how they think vegans survive is an interesting question, though many of them probably don't think we do). On the other hand, once "educated", most vegans have the diametrically opposite view, considering it impossible for someone not to get enough protein on a vegan diet.

The truth lies somewhere in the middle. It is easy to get enough protein on a vegan diet if you eat multiple servings of high-lysine foods (legumes, seitan, amaranth, quinoa, pistachios, and pumpkin seeds) each day. But there are many vegans who are probably not eating enough high-lysine foods.

Legumes include soybeans and their products (tempeh, tofu, soy milk, soy meats, etc.), beans (garbanzo, kidney, pinto, etc.) and their products (falafel, hummus, refried, etc.), peas (green, split, black-eyed, etc.), lentils, and peanuts.  Vegans who do not eat enough calories to maintain their weight also need to pay special attention to making sure they are getting enough protein.

DBM COMMENT

DBM DO NOT make use of soy/soya products on their programs, for a whole host of reasons, not the least of which is that the worlds crop of soy is Genetically Modified. Peanuts are also not made use of on DBM programs due to mycotoxins.

Note: Read more on Genetically Modified foods on this link.  Peanuts are also not made use of on DBM programs due to mycotoxins.

High Quality or Complete Proteins

Proteins are made out of chains of amino acids. Some amino acids can be made by the body (generally from other amino acids), but some cannot. The ones that cannot are known as "essential" or "indispensable."

Twenty amino acids are used to build protein, but they are not the only amino acids. Carnitine and taurine are amino acids which are not building blocks of protein, but the discussion here is limited to the protein amino acids.

Because some amino acids are essential, the RDA for amino acids should be as important as the RDA for protein. But because the RDA for protein takes into account the RDA for amino acids, the amino acid RDA is rarely mentioned. The essential amino acids are found in fairly consistent amounts in average Western diets and the RDA for protein is calculated with typical diets in mind.

Proteins in the human body tend to have a consistent percentage of the essential amino acids. The percentages of essential amino acids in both animal and soy products closely mimic those found in human proteins, and they are, therefore, considered complete or high-quality protein. Non-soy plant proteins have a lower percentage of at least one amino acid, although all legume products are pretty close to soy.

Some people are under the false impression that all non-soy plant foods are completely devoid of at least one essential amino acid. The truth is that all plant proteins have some of every essential amino acid. As a general rule, legumes are lower in the amino acid methionine while most other plants foods are lower in lysine.

In an effort to make sure vegetarians were getting enough of all the amino acids, in the early 1970s in her book Diet for a Small Planet, Frances Moore Lappe popularized the idea of combining plant proteins at each meal in order to get a "complete" protein. By mixing beans and grains, you can make sure that you are getting both methionine and lysine at each meal.

It is now well known that our livers store the various essential amino acids and so it's not critical to combine different protein sources at each meal. The 2009 American Dietetic Association's Position Paper on Vegetarian Diets says:

"Plant protein can meet requirements when a variety of plant foods is consumed and energy needs are met. Research indicates that an assortment of plant foods eaten over the course of a day can provide all essential amino acids and ensure adequate nitrogen retention and use in healthy adults, thus complementary proteins do not need to be consumed at the same meal."
For more information on which foods have "complete" proteins, see JackNorrisRd.com blog post, Complete Proteins.

Article Sources::

  1. fitday
  2. Veganhealth.org
listing-2-amino-acids-f85573baade1e78e8e5a709141b21ac4.jpg
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Histidine
Histidine
Isoleucine
Isoleucine
Leucine
Leucine
Lysine
Lysine
Methionine
Methionine
Phenylalanine
Phenylalanine
Threonine
Threonine
Tryptophan
Tryptophan
Valine
Valine