You learned long ago in science class that amino acids are the building blocks of protein. But do you know what else they do and why it’s important to make sure you’re getting adequate amounts?
There are 20 amino acids in the human body and they’re classified as nine essential amino acids, and eleven non-essential amino acids. Essential means the body can’t make them; they must be obtained through diet. Non-essential amino acids are naturally produced by the body.
Besides their role as building blocks of proteins, some amino acids are necessary for health maintenance, growth, reproduction, and immunity. These are called functional amino acids. Some amino acids are both essential and functional.
Dietary supplementation with one or a mixture of these may be helpful for supporting certain health conditions, optimizing metabolic function, and enhancing muscle growth and athletic performance. Each protein has its own sequence of amino acids. The sequence makes the protein take different shapes and have different functions in the body.
If you think you might benefit from taking an amino acid supplement or just want to learn about which foods contain certain amino acids, please read this important newsletter.
Wishing you a wonderful start to summer!
Why Amino Acids Matter: The Foundation of Protein & Optimal Health
Amino acids have important functions in both nutrition and health Amino acids have numerous vital functions in the body. They break down food, grow and repair body tissue, make hormones and neurotransmitters, provide an energy source, maintain healthy skin, hair and nails, build muscle, boost the immune system, and support a healthy digestive system.1 The types of amino acids and the way they’re combined determine the function of each protein.
Here are 8 important amino acids you should know about:
1. L-Arginine
l-Arginine is a non-essential amino acid, meaning your body produces it naturally. It’s found in protein-rich foods but taken as a supplement it supports heart health and athletic performance since it promotes nitric oxide production. Nitric oxide is important for helping to relax arteries and blood vessels. This supports unrestricted blood flow.2
Foods containing L-Arginine: nuts and seeds, red meat, chicken, turkey, salmon, haddock, tuna, legumes, and dairy.
L-Arginine:
- Promotes nitric oxide production
- Helps relax arteries and blood vessels
- Supports sexual function in men and women
- Helps regulate immune response
- Supports wound healing
2. N-acetyl-Cysteine (NAC)
N-acetyl-Cysteine (NAC) is one of the best researched amino acids. It was first used as an antioxidant antidote to acetaminophen overdose, which can cause severe liver damage in high doses. Later, it was developed as a therapeutic for its ability to break up mucous in the lungs. Now we know that it can raise glutathione levels which is significant because glutathione is one of the body’s most important natural antioxidants.3, 4, 5
NAC is produced by the body and is available as a nutritional supplement. It isn’t found in food, but you can increase your body’s NAC and glutathione levels by eating foods rich in L-cysteine and sulfur, precursors to NAC: poultry, beef, pork, dairy, legumes, eggs, whole grains, nuts & seeds, legumes, and garlic, onions, broccoli, cabbage, and Brussels sprouts.
NAC:
- Supports liver and kidney function
- Detoxifies the body from acetaminophen overdose
- Supports heart health
- Thins mucous
- Helps raise glutathione levels
- May help protect the brain from oxidative stress.
3. L-Glutamine
L-Glutamine is the most abundant amino acid in the body and accounts for 60% of the intracellular amino acid pool. It’s essential because a deficiency can occur rapidly after illness or injury. Glutamine is used as an energy source and is also the primary fuel source for rapidly dividing cells like epithelial cells during healing.6
L-Glutamine is produced in the body, available as a nutritional supplement, and is also found in these foods: beef, chicken, fish, dairy products, eggs, tofu and beans.
L-Glutamine:
- Supports the immune system
- Supports gut function
- Helps support recovery after surgery
- Helps heal burn victim
4. Leucine
Leucine helps your body make protein and growth hormones. It also helps grow and repair muscle tissue, heal wounds, and regulate blood sugar levels. It is essential; your body can’t produce it so you must get it from food and/or supplements.7
Leucine is found in: beef, chicken, salmon, eggs, dairy, whey protein Greek yogurt, lentils, edamame, tofu, and beans.
Leucine:
- Helps build and maintain muscle mass while preventing muscle breakdown
- Supports energy production during periods of high demand
- Counteracts muscle loss in older adults
- Supports recovery after strenuous exercise.
5. Lysine
Lysine is an essential amino acid. Your body can’t make it naturally so it must be obtained from food and/or supplements. Lysine is important for creating collagen, absorbing calcium, and producing carnitine for energy metabolism.8
Lysine is found in meat, chicken, lamb, mussels, shrimp, oysters, salmon, tuna, cod, milk cheese, yogurt potatoes, peppers, leek, avocado, dried apricots, pears, soy, kidney beans, chickpeas, macadamia nuts, pumpkin seeds and cashews.
Lysine:
- Supports healthy skin, bones, and cartilage
6. L-Citrulline
L-Citrulline, a non-essential amino acid, helps boost nitric oxide production, as does L-arginine. It can be taken as a supplement. Unlike other amino acids, it doesn’t build proteins. It plays a role in the urea cycle, helping the body dispose of ammonia and other harmful substances. It also supports vasodilation, relaxing and expanding blood vessels.9
Although scarce in most foods, it can be found in watermelon, cucumbers, cantaloupe, pumpkin, summer squash, zucchini, and bitter melon.
L-Citrulline:
- Supports muscle recovery and athletic performance
- Relaxes blood vessels and supports blood flow
- Supports sexual function in men
- Increases endurance by improving oxygen delivery to muscles
7. Taurine
Taurine is manufactured in your body through the synthesis of two other amino acids—methionine and cysteine. It is found in greatest concentration in the heart and brain. Like citrulline, taurine also doesn’t build proteins. It’s one of the most abundant amino acids in the brain, retina, muscle tissue, and organs in the body.
Taurine’s function includes keeping potassium and magnesium inside the cells of your body while keeping excessive sodium out. Taurine is helpful in fighting tissue swelling and fluid accumulation. People with congestive heart failure often have excess fluid accumulation inside their bodies, and taurine can help eliminate some of the fluid.10
Taurine is found in these foods: dairy, eggs, poultry, pork, wild game, and wheat germ.
An important note for vegans: Seaweed is one of the only plant foods that contains taurine. If you eat enough of taurine’s two amino acid precursors, methionine and cysteine, your body can synthesize its own taurine: soy products, legumes, nuts and seeds, and quinoa and oats.
Taurine:
- Promotes heart health
- Supports proper vision
Conclusion
You don’t need to eat foods containing amino acids at every meal. But it’s important to try to get a balance each day. It’s especially important for vegetarians who don’t eat animal foods. Ovo-lacto vegetarians can get enough amino acids by eating eggs, dairy and legumes. Vegans need to be aware of combining the correct foods to make a complete amino acid profile.
In 1971, Frances Moore Lappe published “Diet for a Small Planet, a groundbreaking book about protein combining. The book shows how to combine grains and legumes in the same meal to create a complete amino acid profile. The book is available and has been updated. It’s a classic and makes an important addition to everyone’s collection of books about health and nutrition.
