Protein: Important Functions
What is Protein?
Proteins are made up of building blocks called amino acids. It is a component of many biological compounds such as enzymes, hormones, and antibodies. It can be found to some degree in all body tissues such as skin, hair, muscles, blood, connective tissues, and bones.
Our bodies make 11 amino acids on their own. They are referred to as “nonessential” amino acids since it is not essential for us to consume them within our diet. There are 9 essential amino acids that our bodies don’t make. We must get these 9 amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine) from the foods we consume.
Why is Protein Important?
The body uses protein to repair muscles and keep bones strong. It also plays a role in immune system function, by helping to make antibodies that fight off illnesses and infections. While protein deficiency in Western countries is rare, when it does happen, the symptoms are usually: the breaking down of muscle tissue, oedema, anemia, and slow growth in children.
Protein is also used to make hormones and enzymes. Practically all of the processes and reactions in the body are regulated by enzymes, which are a type of protein. An example of this would be during digestion, when enzymes work in conjunction with bile and stomach acid in order to break down the different foods we eat.
Eating protein can assist with managing a healthy weight, because it helps to promote feelings of satiety (feeling full) after eating. This is because the presence of protein decreases the hunger hormone ghrelin. Protein is also important in controlling blood sugar and lowering the glucose impact after eating a meal.
Having unbalanced blood sugar is often a root cause of many hormonal imbalances, and low amounts of protein in the diet is also associated with low amounts of estrogen in women and testosterone in men. Because of its effect on blood sugar and hormones (both of which greatly affect our mood) protein intake is therefore also linked to our moods. This means getting enough protein ends up playing an important role in managing mental health disorders.
How Much Protein Do We Need?
The RDA (Recommended Daily Allowance) of protein established by The National Academy of Medicine is between 10-35% of daily total calories, or about 0.7 grams per 20 pounds of body weight. This varies a little based on age, sex, and activity levels, but for an average 180 pound male, this would mean an acceptable amount of daily protein would be roughly 63 grams.
While getting enough protein is essential to health, studies have shown that the amount of protein we eat actually matters less than the type of protein we consume. Studies have shown that a diet lower in protein, as long as it is vegetarian-sourced, is more beneficial to overall health and longevity than a diet higher in protein that comes from red and processed meats.
Protein Rich Foods
Protein can be found in a wide variety of foods. A 3 oz serving of chicken, beef, lamb, or salmon can provide anywhere between 20-30 grams of protein. However, there are also many vegetarian sources of protein. Tofu, which is made from soybeans, has 9-10 grams of protein in a 3 oz slice. Tofu also contains adequate amounts of all 9 essential amino acids, which means it is considered a complete protein. An incomplete protein is any food that does not contain an adequate amount of all 9 essential amino acids.
Other examples of complete proteins include beef, poultry, fish, dairy, and eggs. One egg, 1⁄4 cup of almonds, and 2 tablespoons of peanut butter each provide about 6 grams of protein. A ½ cup of cottage cheese or greek yogurt contains double that amount, clocking in at around 12 grams of protein in a single serving. Wheat possesses a great source of plant based protein, due to the gluten in it. Seitan, a meat replacement made of gluten, is very high in protein. It contains around 20 grams in a 3 oz serving.
All of these high protein food examples I have listed are also very common food allergens. Luckily, there are still many allergy-friendly sources of protein out there!
Protein and Food Allergies
In those with food allergies, the immune system treats a specific protein in a food as a harmful substance that may cause disease. It responds by producing IgE antibodies that will play a role in attacking this protein.
The top 9 most common allergies include peanuts, tree nuts, soybeans, wheat, eggs, fish, shellfish, sesame, and dairy.
Those wanting to increase their intake of vegetarian protein sources without consuming any of the common allergens may do so by including vegetables, seeds, gluten-free grains, and legumes like peas, lentils, and beans.
In a dry ½ cup serving of each:
Peas have over 4g of protein
Beans have about 8 grams of protein
Lentils have 9 grams
Oats have 6 grams
Amaranth has 5 grams
Both quinoa and rice have about 8 grams
A serving of hemp seeds (3 tablespoons) contains an impressive 10 grams of protein. Sunflower seeds have 6 grams of protein in a ¼ cup serving.
Many plant-based protein powders on the market use brown rice, pea, and/or hemp protein which are great allergen-free options compared to the more common soy and whey powders.
In Conclusion…
Protein is an essential macronutrient that is part of a healthy, well-balanced diet. Our bodies wouldn’t be able to perform many functions without it. Now more than ever, it is easy to find protein in a wide variety of food sources. Whether someone eats a lot of meat, wishes to avoid eating meat, or is working around food allergies, there is a way for everyone to obtain an adequate amount of protein in their daily diet.