Proteins and amino acids

Protein complementation is real - it isn't a myth. It recently came to my attention that there are websites that talk about the "myth" of protein complementation so I want to clarify some basic nutrition facts about amino acids, proteins, what protein complementation is and when it may be important to consider incorporating it as part of an eating plan.

Amino acids are the building blocks of proteins

• Different combinations of 20 amino acids make all of the proteins in the body. 
• Some amino acids can be made in the body but others have to be consumed from food (protein sources of food). The ones you need to eat are called essential amino acids. 
• Your body cannot make new proteins without enough of each of the 9 essential amino acids. You get the 9 essential amino acids from the foods you eat and from the natural process of breaking down proteins in your body and reusing the amino acids from the broken-down proteins. It is important to regularly bring new essential amino acids into your body so that there are always enough available to meet your needs. 
• Non-essential amino acids are made in the body. There are 11 non-essential amino acids. 

Protein quality

Animal proteins are considered "complete" and "high quality." This does not mean that animal sources of protein are better or superior to plant proteins. They are called "complete" because animal proteins provide all 9 essential amino acids in the right amount for the human body to use in making its own proteins. They are considered "high quality" because they are easy to digest sources of protein. Keep in mind that animal proteins also contain saturated fat and cholesterol - things that we want to limit in the diet to reduce the risk of heart disease, certain cancers, high blood pressure, etc. We don't need to complement animal proteins because all of the essential amino acids are adequately represented. We also do not need very much animal protein to meet our dietary needs.

Plant proteins are limited ("short") in one or more of the essential amino acids relative to the amount that the human body needs in order to make proteins. Plant proteins are a little more complicated for the body to break down and use so it takes a little more dietary plant food in the diet to meet essential amino acid needs. Plant proteins are limited in at least one essential amino acid and are a little more difficult to digest and are are considered "incomplete" and "low quality." Don't be mislead by the terms "low quality" and "incomplete" - plant proteins are a very healthy and sustainable source of protein. Furthermore, soy and quinoa are complete proteins and soy is also considered a high quality protein because it is easier to digest.

Protein complementation

Protein complementation is a way of combining proteins that are limited in different essential amino acids together so that you get a complete set of essential amino acids. For example, rice is limited in lysine but has lots of methionine and cysteine. Beans are limited in methionine and cysteine but have lots of lysine. When you have beans and rice, you provide your body with a complete set of essential amino acids.

By rusvaplauke [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

Protein complementation can happen throughout any 24 hour time frame - it is not limited to a single meal. The body is always breaking down proteins and releasing amino acids into the blood so that the amino acids can be re-used to build new proteins.

Plant proteins are excellent sources of protein and eating a variety of plant-foods each day is the easiest and best way to make sure a vegetarian (or anyone) gets their essential amino acids. Vegetarians who eat a variety of plant-based foods easily meet their protein needs. A diet that contains whole grains, nuts, seeds, legumes, and soy is going to provide all the essential amino acids.

Who may benefit from protein complementation?

• People new to vegetarianism
• Anyone looking for new ways to plan meals and limit animal proteins in their diets

If a vegan doesn't eat a variety of plant foods for an extended period of time, she may encounter some challenges that inhibit her ability to make body proteins. One day (or even a week) of not eating well on a vegan plan is unlikely to cause many problems. Somebody with chronically poor eating habits or who is new to a vegan diet may benefit from focusing on protein complementation to make sure that they know how to make healthy and varied protein choices. Over time, it hopefully becomes second nature. 

Final thoughts

It seems as if almost everyone (and their acai berry bush) posts videos, podcasts and blogs passionately promoting positions, gimmicks, how-tos, products, or top-ten lists about nutrition. As a society, we open our arms and warmly embrace anyone who wants to climb the virtual pulpit and preach about nutrition. We accept it when someone (anyone) tells us that everything you've ever known about nutrition was an outright lie. Whatever they feed us, we gobble it up. Qualifications be damned because pesky issues like facts, research and evidence-based knowledge and relevant credentials don't apply when it comes to spreading nutrition knowledge across society.

Protein complementation isn't a myth. It isn't bullshit. Protein complementation is a way to develop healthy eating habits and plan meals, especially for someone new to vegetarianism or looking for ways to include more plant-based foods in their eating plan. A plant-based diet is a very healthy approach to eating. Plant-based proteins are low in saturated fat, cholesterol, and provides lots of vitamins, minerals, fiber. A vegetarian, particularly a vegan - a person who does not eat any animal-based foods at all - who eats a variety of foods, will easily meet her protein needs and get all of her essential amino acids.