If you’re like me, you’re probably paying attention to how what you eat affects you, and constantly honing it in to optimize gut health and the health of your stools. Lately, I’ve gotten a few requests from coaching clients to speak more on protein and specifically Amino Acid content as it relates to this! So, here’s a little science lesson on the basics of the macronutrient, protein. Hope this helps you in some way! Feel free to leave comments on this post for me to consider adding other factors in, or about how this has impacted you.
Protein is the building block of all body tissues and is composed of individual amino acids linked together in a chain.
There are 4 calories per gram of protein energy
Protein provides amino acids that are then reassembled in the body into complete proteins needed for survival, such as enzymes, muscle, skin, and more
We need a lot more protein than we think: at least 0.5 to 1 gram per pound of body weight depending on your activity levels and other dietary needs. For my active lifestyle I need to be on the end of that spectrum, which means almost 150g or 600 calories from protein per day at a minimum.
Factors that determine protein quality
The amino acid profile: Complete proteins contain all essential amino acids, whereas incomplete proteins are lacking in one or more of the essential amino acids.
There are 20 amino acids but these 9 are most essential and we need to get them from our diet: Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Leucine, and Lysine
Bioavailability: No matter how much protein a food has, it will not benefit you if you cannot digest and absorb it.
I will *always* recommend getting your amino acids from real, whole foods... not supplements or other powders as the primary source.
Toxicity: Some proteins are more likely to cause an immune response or allergic reaction.
The key point to remember:
The best proteins contain all essential amino acids in a bioavailable form and have low potential for toxicity.
What foods are the best protein sources?
Meat, poultry, seafood, and eggs should form the bulk of your protein intake.
Seafood, poultry, and red meat are the most concentrated sources of protein.
Dairy products can also be a source of high-quality protein (as tolerated by your gut).
Important for vegan and vegetarian friends:
Fruits, vegetables, nuts, and seeds are good sources of micronutrients but are low in absorbable protein.
Grains and legumes are poor sources of protein compared to animal products. They also contain anti-nutrients that reduce the absorption of amino acids and can provoke an immune response (like phytic acid). That said, a moderate amount of grains and legumes properly prepared, such as soaking and sprouting to decrease toxicity, may be well tolerated by some individuals. When not prepared properly, there’s a lot of toxicity in eating legumes.
Hemp is not fully complete in amino acid profile, as it’s low on Lysine:
While most people don’t need to worry about it, if you really want to ensure that you’re getting enough lysine in your diet, focus on eating foods relatively high in lysine to balance out hemp’s deficiency.
In terms of plant-based protein sources to get proper lysine, here are the top sources (lysine per 100 grams)
Adzuki beans, Lentils, Oats, Kidney beans, Black beans, Mung bean, Buckwheat, Chickpeas
Protein has gotten a lot of flack over the decades
Getting too much protein from lean muscle meats and eggs will offset the amino acid balance of methionine to glycine ratio. It's important that we get complete proteins, which means it has the proper balance of all the amino acids. Here's a bit about that, straight from a book I source from constantly, The Paleo Cure by Chris Kresser:
The theory had been that higher protein intakes increase levels of IGF-1, and high IGF-1 levels encourage the growth of cancer cells. Recent research, however, has found that the amino acid methionine is the primary driver of the increased IGF-1 levels observed with higher protein intakes. Glycine, on the other hand, does not have the same potentially harmful effects as methionine in excess. Methionine is found primarily in muscle meats and eggs. Some studies have shown that consuming higher amounts of glycine may have the same life-extending, IGF-reducing, health-promoting effects as restricting intake of methionine or total protein overall.
Maintain a healthy methionine-to-glycine ratio by consuming glycine-rich foods like bone broth and more gelatinous cuts (collagen-rich!) of meat such as oxtail, shanks, and brisket.
So to counter the possible negative effects of eating too much protein: just eat like our ancestors did by eating "nose to tail" to get the proper balance of amino acids and complete proteins.
The effects of eating “nose to tail” make foods more like superfoods:
Bone broth is rich in glycine (which as noted above is the amino acid that balances the other amino acids found in muscle meats and egg yolks) and can improve mood and digestive function. Stock contains minerals in a form the body can absorb easily—not just calcium, but also magnesium, phosphorus, silicon, sulfur, and trace minerals. Broth has a long history of use as a medicinal food in almost all cultures, including our own. Your grandmother knew best! I recommend consuming 1/2 to 1 cup of bone broth per day in the form of soups, stock, stews, or sauces (bone broth makes an excellent base for a sauce or stew).
Nose to Tail is unquestionably more nutritious! Eat a combination of lean muscle meat (steak and chicken breast) but also the organs, skin, cartilage, and bones. Fattier cuts provide nutrients that work synergistically.
For example, the amino acid methionine, which is found in abundance in lean proteins, is unable to fulfill its important functions without adequate amounts of B vitamins (especially B6, B12, and folate), choline, and glycine.
It’s cost saving: Organ meats and more gelatinous cuts (brisket, chuck roast, chicken legs with bones/skin, etc.) are less expensive than muscle meats such as (boneless/skinless) chicken breast.
It’s more tasty! These cuts are the most flavorful, tender, and delicious parts of the animal. Get experimental! Even animal liver can be made in a way that is satisfying.
Amino Acids & Micronutrients:
The term “nutrient density” refers to the presence of micronutrients and amino acids (the building blocks of protein) in food. The body needs about 40 micronutrients for proper function. Suboptimal intake of any of them will lead to disease and a shorter lifespan. As relates to the topic of discussion:
Vitamin B6 for example is necessary for the liver to convert the amino acid tryptophan into niacin (Vitamin B3) or serotonin, and it is involved in over 100 enzymatic reactions related to carbohydrates, amino acids, and fatty acid metabolism. It also supports methylation, and plays a crucial role in forming heme.
Vitamin B12 is involved in metabolism in every cell of the human body, including how we make our DNA. Without it we wouldn’t process fatty acids and amino acids, to make things like skin, collagen, red blood cells, or create energy or myelin (the protective insulation around our nervous system). It also works with folate (Vitamin B9) to support methylation.
If you have B12 deficiency (common in vegetarian and vegan eaters), there may be improper methylation of toxic amino acid byproducts, which leads to memory loss, mood and behavior changes, and even delirium or psychosis. Some symptoms of this often start at the feet and move up the body: altered sense of body position (like abnormal gait), tingling/numbness/crawling skin, faintness due to sudden changes in blood pressure, exercise intolerance, and poor energy or fatigue.
For good skin health: Sulfur-containing amino acids are found in egg yolks, meat, poultry, fish, garlic, onion, brussel sprouts, asparagus, kale, broccoli, and cabbage. Fermentation makes sulfur more bioavailable (as with sauerkraut).
On Anxiety, Depression, & Mental Health:
Better balance of amino acids in general will help with the production of serotonin and melatonin.
And thus malnutrition will contribute to anxiety, depression, and cognitive disorders:
Inadequate macronutrients ratios (protein, fat, and carbohydrates)
Too little or excess protein can exacerbate mood disorders because neurotransmitters are created from amino acids provided by protein in the diet
Make sure your diet contains all of the essential amino acids
Again the ideal protein intake is between 0.5 and 1 grams per pound of body weight or 1 to 2 g/kg of body weight per day
Insufficient or excess micronutrients as noted above
Excess intake of methionine, the amino acid that is found in muscle meats and eggs, can lead to imbalance in the methionine-to-glycine ratio (excess methionine and insufficient glycine), and that will lead to neurological symptoms
It is recommended to increase intake of glycine contained in bones, joints, tendons, bone broth, cuts of meat such as chuck roast, brisket, oxtail, or shanks that have more collagen in them to protect against neurological conditions and improve brain function
Balancing this amino acid ratio will also help with sleep and anxiety
(The balance of methionine and glycine is so crucial, I’ve mentioned it here again now for the third time! Cannot stress this enough!!)
Related to Ketogenic Diet and Ketosis:
The amino acid Leucine is ketogenic. Its consumption naturally improves energy metabolism in the brain and reduces inflammation in the microglia.
Ketogenic diet is typically best for individuals with:
Cognitive neurological disorders: Alzheimer’s, Parkinson’s, dementia
Mood disorders: such as depression, brain tumors, traumatic brain injury, seizure disorders
Severe blood sugar disorders
Heavy metal exposure - Metals such as mercury, aluminum, and lead can cause toxicity in the central nervous system by interfering with uptake and release of certain neurotransmitters.
This also contributes to demyelination of nerves, autonomic dysfunction, and abnormal neuronal migration.
This will interrupt excitatory amino acid pathways causing neurotoxic accumulation of serotonin, aspartate, and glutamate, which in turn causes overstimulation, anxiety, and hyperactivity.
Symptoms of toxicity: neuropathy, ataxia, spasticity, memory loss, dementia, impaired hearing and vision, as well as depression, anxiety, and then Alzheimer’s- or Parkinson’s-like symptoms.
It is up to you to pursue heavy metal testing from a qualified practitioner!
Be intentional with your consumption of seafood, for the possibility of it containing more mercury than selenium.
Be weary of mercury dental amalgams.
Taurine, glycine, and methionine are amino acids that also promote healthy phase 2 detox pathways and healthy cell metabolism.
So how does all of this land for you?
Leave comments below...
The Paleo Cure by Chris Kresser
Functional Health track course content from the ADAPT Health Coach Training Program via Kresser Institute
Article on Biochemistry, Essential Amino Acids: https://www.ncbi.nlm.nih.gov/books/NBK557845/