What is Protein? What are the different types of proteins?
One of the three macronutrients your body needs to function properly (along with fats and carbohydrates), proteins are primarily important for tissue growth and repair, but also necessary for digestion, metabolism, and the production of antibodies to fight infection. Comprising 10% of your brain and 20% of your heart, liver, and skeletal muscles, protein is obviously key to maintaining a strong, healthy body. What you may not realize, however, is how important it is for a healthy mind.
When you digest protein, it’s broken down into its component amino acids, which are then reassembled into 50,000 different forms your body can use for things like hormones, enzymes, and neurotransmitters. Not only do these amino acids form the building blocks of your brain’s neural network and have significant impact on your mood and brain function, but are especially important in infants’ developing brains.1Specifically, the protein neurexin, is responsible for directing new nerve cells to their correct locations in the brain where they form their initial connections.
There are differences in the types of proteins you eat, some are “complete;” others are “incomplete,” and you need them both. Proteins are made of 20 or so building blocks called amino acids. Complete proteins contain the 9 essential amino acids your body needs to build new proteins. Essential amino acids are ones the body can’t produce on its own. Animal sources of protein tend to be complete. Other protein sources lack one or more of the essential amino acids; these are called incomplete proteins. These include fruits, vegetables, grains and nuts.
Because the body doesn’t store amino acids, like it does with fat or carbohydrates, it needs a fresh supply of them every day to make new proteins. Complete and incomplete proteins play an equally important role in this process. The best way to get all the protein you need is to pick from wide and varied sources.
There are Two types of Proteins.
- Incomplete Proteins
- Complete Proteins
Plant foods are considered incomplete proteins because they are low or lacking in one or more of the Amino acids we need to build cells.
Incomplete proteins found in plant foods can be mixed together to make a complete protein. As a general rule, grains, cereals, nuts, or seeds can be eaten together with dried beans, dried peas, lentils, peanuts or peanut butter. Examples of these combinations include peanut butter on wheat bread, rice and beans, and split pea soup with corn bread. Incomplete proteins found in plant foods can also be combined with small amounts of animal foods to make a complete protein. Examples include macaroni and cheese, and tuna noodle casserole.
There are two main classes of Amino acids.
It is essential that you get essential amino acids via your diet because your body cannot make them. Contrast this to nonessential amino acids, which your body can synthesize on an as-needed basis in addition to getting them via your diet.
When it comes to protein, all animal sources of protein will provide you with all the essential amino acids that your body needs. These are protein sources such as:
If you don’t eat animal products, then you must get your protein from plant sources. The catch with plant protein sources is that they do not always contain all the essential amino acids in required proportions, making them incomplete proteins. Below are some plant protein sources that contain all the essential amino acids. When looking at this list, it is important to consider the total amount of protein as well. While chia seeds do contain all the essential amino acids, one tablespoon of chia only contains three grams of protein.
Finally here are common plant protein sources that are incomplete protein sources:
Everyone knows that protein is essential to good health—we need it to feel full, have energy, build and repair muscle, process nutrients, and boost immunity, among other vital roles. The Recommended Dietary Allowance (RDA), which is the minimum amount you need to be healthy, is 0.8 grams of protein per kilogram (0.36 grams per pound) of body weight per day—which is roughly 46 grams for an average woman. But not all protein sources are equal. Only some are “complete proteins,” which means they contain all the essential amino acids—those building blocks of proteins that we must get from food—in the perfect proportion for our dietary needs. Christopher Gardner, PhD, professor of medicine and director of nutrition studies at the Stanford Prevention Research Center, suggests thinking of protein as a Scrabble game. “Some amino acids you need over and over again, like the letter E, and some you don’t need as many of, like Z,” Dr. Gardner told Health magazine. Animal products like chicken and steak provide the right letters to spell words (build proteins) in the right combinations. Plants provide all the letters, too, just not in the optimal amounts. If you’re cutting back on meat or going full-on vegetarian or vegan, it’s important to find sources of complete protein for your body. Here’s how to get more protein in your diet.
Complete protein: Pasture-raised eggs
Eggs may seem like the obvious first choice, but according to Rachel Meyer, certified personal trainer and holistic nutrition coach, the type of eggs you’re eating is a detail you can’t miss. “Pasture-raised eggs contain 6 grams of protein per egg,” she says. “They also have two times more omega-3 fatty acids and a 25 percent less saturated fat than eggs from confined chickens.” Tired of eating the same fried or scrambled eggs each day? Here are recipes that use eggs that aren’t breakfast.
Complete protein: Greek yogurt
This yummy complete protein is perfect for healthy eaters who’ve grown tired of eating eggs for breakfast each morning. Typically, 8 ounces of Greek yogurt contains about 18 grams of protein. But don’t assume all Greek yogurt is a healthy choice, as flavored brands can be loaded with sugar. Stick with plain and sweeten it yourself with a touch of honey or fresh fruit. If you’re looking to add this healthy dairy to other meals, check out these inspired greek yogurt recipes.
Complete protein: Pumpkin seeds
Pumpkin seeds are delicious when toasted and tossed on a salad, and they are an easy snack to eat on the go. They’re also a complete protein, containing all nine of the essential amino acids your body needs. Pumpkin seeds contain 12 grams of protein per cup, according to Meyer, and eating 1/4 cup will provide you with half of the magnesium you need for the day. “Magnesium can reduce frequency of migraines and lessen the effects of depression,” explains Meyer. “Pumpkin seeds are also high in tryptophan, a amino acid your body uses to promote better sleep.” These are signs you could be deficient in magnesium.
Complete proteins: Barley and lentils
These plant-based proteins aren’t complete proteins when eaten alone, but eaten together, they’re called complementary proteins because each contains the essential amino acid the other is lacking. So together, they make a complete protein. Barley has 23 grams of protein per cup and is beneficial for controlling blood sugars, according to Meyer. In addition to being high in protein, lentils are also high in fiber and folate, according to medicalnewstoday.com. Other complementary proteins are legumes with grains, nuts, seeds, or dairy; grains with dairy; dairy with nuts; dairy with seeds and legumes. Keep in mind, however, that you don’t always have to get complete proteins at every meal as long a you get enough over the course of a day. “For example, if you eat beans—an incomplete protein—at one meal and a tortilla—also incomplete, but complementary to beans—at the next, your body will be able to get the essential amino acids from both that it needs,” David L. Katz, MD, director of the Yale-Griffin Prevention Research Center, told Oprah.
Complete protein: Buckwheat
With 23 grams of protein, buckwheat is a whole grain you can’t afford to leave out of your diet. Buckwheat flour can be used for baking, or to make pancakes, crepes, or muffins. You might not realize that soba noodles contain buckwheat flour.
Combining incomplete proteins to form a complete protein
If you’re a vegetarian or vegan, or if you limit the amount of animal products you consume, you can combine incomplete, plant-based proteins to meet your body’s needs. Combinations include:
- Nuts or seeds with whole grains (peanut butter on whole wheat toast)
- Whole grains with beans (beans and rice; hummus and pita bread; bean-based chili and crackers; refried beans and tortillas)
- Beans with nuts or seeds (salad with chickpeas and sunflower seeds)
“You don’t have to eat all of those in every single meal and not even in your full day,” says Komar. “But it’s a good idea to get a variety.”
Complete Proteins, Incomplete Proteins, and Your Diet
Despite the fuss that is often made about complimentary proteins, it is important to recognize the context that is useful. In the American vegetarian diet, food choices are so varied and in such abundance that the lack of essential amino acids is rarely a problem. Especially when you also take into account the abundance of soy products consumed, preventing deficiencies in essential amino acids should not be a problem. And if you are a lacto-ovo-vegetarian, then you don’t need to concern yourself with finding complimentary proteins for incomplete proteins, as the amino acid profiles for dairy protein and eggs are two of the best out there.