Delving into the world of fitness and nutrition, it’s easy to be overwhelmed by talk of nutrients. The one you inevitably end up hearing about – a lot— is protein.
But what is it? You’ve probably heard or read about it as a big part of building muscle, but there are some other important and often-overlooked aspects of the different protein sources that you may not know.
Let’s start with the basics…
What Is Protein?
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. Specifically, the protein neurexin, is responsible for directing new nerve cells to their correct locations in the brain where they form their initial connections.
Complete vs Incomplete Protein Sources
Your body needs 22 different types of amino acids to function properly. Adults can synthesize 13 of those within the body (known as non-essential amino acids), but the other 9 must be obtained from food (known as essential amino acids). It’s these essential amino acids that derive the classification of protein as either complete or incomplete.
Complete Protein Sources
Complete proteins are those that contain all essential amino acids in sufficient quantity – these are typically animal-based proteins, but a few plant sources are also considered complete. A few examples are (* indicates plant-based):
- Dairy products (milk, yogurt, whey)
- Hemp and chia seed*
Incomplete Protein Sources
Incomplete proteins are those that don’t contain all 9 essential amino acids, or don’t have sufficient quantities of them to meet the body’s needs, and must be supplemented with other proteins. These include:
- Nuts & seeds
Just because they are incomplete doesn’t make them inferior, though, they just need to be combined to provide the right balance of essential aminos. Proteins that, in combination, make a complete amino acid profile are known as complementary proteins. Here are a few tasty examples:
- Rice and beans
- Spinach salad with almonds
- Hummus and whole-grain pitas
- Whole-grain noodles with peanut sauce
Complementary proteins don’t necessarily need to be eaten together, but since your body doesn’t store amino acids for later use in protein combining, they should be eaten throughout a day’s meals.
Plant vs. Animal Protein Sources
A bit of a controversy is brewing over whether animal or plant-based proteins are better for you. Some nutritionists argue that humans are better suited to digesting animal proteins since they are closer to our own biological makeup and contain all the amino acids we need to survive. On the other side, many contend that plant-based proteins are healthier and animal-based proteins are not necessary if you have proper variety in your diet.