What is Protein?
Previously, we discussed why protein is important for our metabolism. As promised, we’re going to dive in a little deeper to explore protein and why we should care about it.
Protein is one of the important nutrients our body needs to perform countless functions. It fuels every function of cells. It is found in every body tissue. It facilitates growth and development, repair of damage, and enables you to keep functioning.
There are thousands of different proteins made in the body. These include
- keratin- hair, nails, skin
- muscle
- bone marrow
- red blood cells
- enzymes
- hormones
There are about 200 amino acids that we know of so far. Complete protein is made up of 22 of those amino acids. Some books say 20, some say 21, some say 22. They’re still learning and discovering.
Think of amino acids as Legos, and protein is what is being created. Most of the necessary amino acids are always on hand because the body can make them. 9 of them are “essential” or “indispensable” because the body can’t make them, so we need to consume them.
- histidine
- isoleucine
- leucine
- lycine
- methionine
- phenylalanine
- threonine
- tryptophan
- valine
The amino acids your body makes, you don’t need to worry about. They are referred to as “non-essential”.
- alanine
- asparagine
- aspartic acid
- glutamic acid
Some amino acids you don’t need to worry about until you are sick or under stress. Then your body needs more of them but can’t make enough, so you need to consume them. These are often called “conditional”.
- arginine
- cysteine
- glutamine
- tyrosine
- glycine
- ornithine
- proline
- serine
Then, there are 2 recently discovered amino acids.
- selenocysteine
- pyrrolysine.
These are rare amino acids.
How Does the Body Use Protein?
When we eat protein rich food, the digestive enzymes break protein down into individual amino acids. Then, when a certain type of compound is needed in the body, it takes the amino acids it needs and configures them into that type of protein.
Imagine it this way, you have a cool Lego star fighter. It gets broken down and all the individual Legos are thrown into a collection of Lego bricks.
- the star fighter is protein
- taking it apart is digestion
- the individual bricks are amino acids
Then, when your body needs to make some new protein, your body takes out the bricks it needs from the pool of bricks and builds your new protein creation. Unfortunately, the pool of Legos (amino acids) doesn’t hang around long. There is constant turnover. Hopefully, you have all the pieces you need, otherwise you have to take some pieces from another creation, like that castle you built the other day. You might not want that castle broken down, so you need to make sure you have a steady supply of bricks coming in everyday. Practically speaking when your body is short of amino acids and needs them, instead of a “castle”, it tends to break down your muscle instead.
After the protein is broken down, the leftover carbon, hydrogen and oxygen we didn’t use are converted to glucose and the nitrogen left from the conversion (ammonia), is converted to urea and excreted from the body.
Importance of Protein
You need to give your body proper building materials. The body is in a state of constant repair.
It serves as digestive enzymes and hormones, comprises your connective tissues (tendons, ligaments, collagen, bone, blood, etc.) and muscles. It is involved in the formation of DNA and RNA, protects your cells, substance transport, produces energy in cell mitochondria, removal of waste produced during metabolism.
Protein should be eaten everyday, because your body can’t store it.
Protein Quality
Proteins are either high quality or low quality.
High quality are complete proteins, meaning they contain ALL the amino acids. These are found in animal protein such as dairy, eggs, poultry, fish and beef. We use these most efficiently because their bodies are similar to ours.
Low quality are incomplete proteins, meaning some of the amino acids are missing or in very small amounts. These come from plant proteins such as peanuts, soy, beans, broccoli, etc.
Biological value– Digestibility should also be considered. How much of the food is digested and absorbed into the body? What isn’t digested is excreted. This is given in percent. Animal proteins have a higher digestibility than plant proteins. The egg, for example, has 100% digestibility, while rice has 59% and oats 84%.
You can make plant proteins complete by combining complimentary foods like rice and beans. However, the current belief is that combining foods is not necessary as long as we eat a variety of foods throughout the day.
Protein Sources
Unfortunately, for those who typically eat the Standard American Diet, their protein choices are poor with over consumption of processed meat filled with nitrates, hormones, antibiotics and other chemicals, fatty red meat, deep fried foods, farmed meat, and vegetables soaked in pesticides and other chemicals, GMOs, etc. These are not healthy choices and will likely lead to inflammation and disease.
Buy the best quality you can afford with the best ingredients.
🐓 Good animals protein sources 🐓:
-fish- cold water, wild caught, small mouth fish such as salmon, cod, trout. Avoid farmed fish
-canned- salmon, skipjack tuna, sardines
-cold water shrimp, lobster, clams, mussels
-eggs- organic, free range or pasture-raised
–lean protein- Buy organic, hormone-free, antibiotic-free, pasture-raised as much as your wallet allows. These are a higher quality protein. Limit red meat to occasionally.
- chicken
- turkey
- bison
- lean beef such as sirloin or top round
- lean pork such as tenderloin
- venison
- game meat
-dairy- Hormone and antibiotic-free, organic cheese, Greek yogurt, cottage cheese, ricotta cheese, whey. Limit conventional milk.
🍚 Good plant protein sources 🍚:
-quinoa, amaranth…
-vegetables- asparagus, broccoli, Swiss chard, spinach, soy, Brussels sprouts, kale…
-beans and legumes- peanuts, lentils, beans, peas…
-grains- oats, wheat, rice, teff…
-nuts and seeds- almonds, cashews, hemp seeds, pumpkin seeds…
-Avoid soy, except for fermented miso, tempeh and shou…
Animal or plant protein? You have to decide that for yourself…
Getting protein from whole food sources is best. I combine plant and animal proteins. Vary your foods to get a wide variety of nutrients. Animal proteins lack fiber, antioxidants, phytonutrients and other vitamins and minerals. Be sure load up on vegetables with your animal protein. Plants proteins lack or are low in certain nutrients as well such as essential amino acids, B-12, DHA and others. For best results, combine proteins.
Protein Supplements
Supplements are available but should be used as a supplement, not as the main source of protein. Use them when you need to fill in gaps. Whole foods are full of other nutrients, vitamins and minerals that are not found in processed supplements. They taste much better too!
Better supplement powders are made from whey, egg or pea/rice.
Avoid supplements full of fillers, sweeteners and other unhealthy ingredients. Know what is in your food.
If you use protein powders, research whether they’ve undergone independent testing. Some protein powders have been shown to be high in arsenic, heavy metals, etc. Also consider purchasing powders that avoid pesticides, hormones, antibiotics, etc.
How Much Protein Do We Need?
The amount of protein you should consume depends on your age, health and activity level.
The Recommended Dietary Allowance (RDA) is 46 grams for women and 56 g for men. This is .6-.8 grams per kilogram of lean body weight. (.4 grams per pound)
This is the minimum amount to make sure you survive. That is not the same thing as an optimal amount so you can thrive. The RDA is NOT enough to prevent age related muscle loss or build muscle if you are training hard.
Fans of the vegan or vegetarians diets say only 10% -15% is necessary. They also believe protein from animal sources cause disease.
People need more protein when
- they are training hard
- they are in a calorie deficit, they need to avoid muscle loss
- older people may require more because their bodies aren’t as good at synthesizing protein anymore. They are also prone to muscle loss (sarcopenia) due to inactivity leading to frailty and lower quality of life. They should also move more.
- they have low body fat
- they are ill or injured
The National Academies division of Health and Medicine sets the acceptable intake at anywhere between 10% – 35% of your daily calories.
Generally speaking, protein should be about 30% of your diet. For the average person it should be .8 grams per pound of lean body weight – more if older, injured or building muscle.
Spread it over the course of the day, rather than eating it all in one sitting.
Protein Deficiency
When you are deficient in protein, your body can’t find enough building blocks to repair cells, so it takes apart existing muscle tissue.
Symptoms of protein deficiency can include
- weak muscles
- anemia
- fluid retention
- lack of focus
- emotional instability
- fatigue
- slow wound healing
- deficient neurotransmitter synthesis for mental health
Protein deficiencies are uncommon in people who eat a varied diet except for maybe people who have eating disorders, have malabsorption issues, are fruitarian, exercise excessively, or live on carbs.
Excessive Protein Problems
Problem: High protein diets can be constipating.
Solution: This is due to lack of fiber in your diet. Load up on vegetables and find ways to get more fiber into your diet. Get at least 35 grams of fiber.
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Problem: Excessive saturated fats in foods such as dairy and red meat or processed meat stimulate the liver to create cholesterol, contributing to heart disease.
Solution: Eat lean sources of protein and limit protein high in saturated fat. In fact, some studies show that eating healthy sources of protein can be beneficial to your heart. Some fat and cholesterol is important for brain health. It is found in all cell membranes.
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Problem: Processed meats or meats with nitrates/nitrites- Meat preserved with nitrites/nitrates when combined with high heat raise your risk of cancers such as esophageal, gastric and leukemia. This includes meats such as hot dogs, cured bacon, sausages, deli meats, jerky, etc.
Solution: Limit or avoid these. Buy uncured meats or bacon.
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Problem: Burnt meat, such as charring it on the grill, creates carcinogens as does high temperature cooking.
Solution: Cook meat at lower temps and don’t burn it.
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Problem: Does high protein cause kidney or liver damage? Not exactly. If your liver and kidneys are healthy, protein should cause no issues. However, if you already have kidney or liver disease, protein will be difficult for your kidneys and liver to process, so it will be better stick with low protein. Not processing protein efficiently in urea or excreting it can cause kidney stones, uremic poisoning or gout. While it doesn’t cause the problem, the point is made that some people have undiagnosed kidney problems.
Solution: Protein doesn’t cause damage. It does increase the waste going through the kidneys. Stay properly hydrated. If you’re not sure about the health of your kidneys or liver, ask you doctor to check first.
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Problem: Some studies indicate that high protein diets leach calcium from bones causing osteoporosis, because calcium is used as a buffering agent. Other studies have shown the opposite, that high protein diets increase bone mineral density. So this is inconclusive.
Solution: You can easily up your calcium by increasing your fruits and vegetables. Bones are made partly of protein, so eating protein helps rebuild bone. Studies show pairing adequate protein with resistance training builds bone density.
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Problem: Protein causes cancer and causes tumors to grow. This is partially true. Protein makes cells grow and multiply faster. This is why we consume it for muscle growth and growing children need it. Unfortunately, it makes all cells, not just good cells grow. The bad cell grow as well. One study in mice showed high protein caused faster tumor growth. However, please note, it did not cause the tumor, the tumors were placed in the mice. It only caused it to grow faster. This is why a cancer patient will be put on a low protein diet.
Solution: Healthy protein has not been shown to cause cancer. If you already have cancer though, it will cause it to grow faster. In this case, stick with a low protein diet or whatever your doctor recommends. If you don’t have cancer, as far as I can tell, there’s no cause for concern except for the points listed earlier. Eat healthy sources of protein, avoid processed meats, nitrates, other questionable ingredients and charring.
Protein is very complicated and there is still so much for researchers to learn. Do your research and decide what is best for you. As always, consult your doctor.
Are you getting enough protein?
What are your favorite sources of protein?
“It is not what goes into the mouth that defiles a person, but what comes out of the mouth; this defiles a person.” Matthew 15:11
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Sources:
Dietary protein and skeletal health: a review of recent human research.
Korn, Leslie. PhD., Nutrition Essentials for Mental Health.
Major dietary protein sources and risk of coronary heart disease in women.
Protein intake and bone health.
Red meat consumption and mortality: results from 2 prospective cohort studies.
Peppers and Planks 