AMINO ACIDS

Proteins are made up of Amino Acid molecules. There are 9 essential amino acids, and they are essential because your body CAN'T make them. Included among these 9 are 3 Branched-Chain Amino Acids (BCAAs), so-called because of their structure, which differs from that of the others.

Consider Amino Acids the rebuild crew. Like Lego.

Every day, your body breaks down muscle, tendon, enzymes, and more. It needs raw materials to rebuild them, and these are Amino Acids. Functions like protein synthesis, tissue repair, and nutrient absorption. They can also help prevent muscle loss and help with sleep, mood, athletic performance, and fat loss. The big question is, which amino acids are optimal for men and women over 50?

Read more about the benefits of protein here.

Branched Chain Amino Acids - BCAAs

The BCAAs are Leucine, Isoleucine, and Valine. They are called branched because their chemical structure contains a branch. Go figure, and they are a subset of the Essential Amino Acids (EAAs) listed below.

Essential Amino Acids - EAAs

There are around 20 amino acids, of which nine are essential amino acids that the body cannot synthesize. These are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. 

Non-Essential Amino Acids

Your body can make these. It doesn't mean they are less important, just that you're not totally reliant on food for them. 

Conditional Amino Acids

Not essential, until life gets real, so to speak. At times, it could be due to illness, training, stress, or aging; your body may not produce enough and may need support.

BCAA v EAA

Leucine helps flip the switch to start muscle protein synthesis. Then the EAAs provide the building blocks needed to build and repair muscle. If you only have BCAAs, you might flick the switch but be short of building materials. That's why a complete protein is important. A complete protein means all the EAAs are present.

Leucine is like the site supervisor, EAAs are the building bricks.

Your nutrition should include protein to keep your body functioning optimally.

BCAAs form 40% of all amino acids in the body, and 18% are found in your muscles. BCAAs include leucine, isoleucine, and valine. 

DAILY USE 

Daily intake falls into 2 areas. Meals and supplements. Both are important, the latter if you're active.

Meal target: 30g plus high-quality protein, 3-4x/ day

Leucine target per meal: 2.5-3 g. 100 g of chicken or red meat contains 25-30 g of protein, with chicken breast slightly higher, pork at 25 g, and mince in the range of 20-27 g. The Leucine content is around the following:

As noted in the table above, it will vary with the meat cut and quality. Easy to get a reckoner of how much protein and leucine you get in a meal.

Don't forget your daily protein intake per kg body weight.

Supplements can then support exercise and activity, and/ or an insufficient dietary protein intake. A complete protein isolate is generally the best option. 

 EAA Limits

1. Histidine: 
   14 mg – Helps digestion, libido, and sleep-wake cycles.
2. Isoleucine:
   19 mg – Helps control blood sugar, healing, muscle development, maintain lean body mass, and boost energy and performance.
3. Leucine:
   42 mg – Helps provide energy during exercise to muscles, muscle growth, and lean body mass, production of HGH (Human Growth Hormone), and the control and regulation of blood sugar.
4. Lysine:
   38 mg – Helps the body absorb calcium, iron, and zinc, promotes the production of collagen, and reduces blood pressure.
5. Methionine + Cysteine:
   19 mg – Helps improve healing, liver detoxification, and copper accumulation.
6. Phenylalanine + Tyrosine:
   33 mg – Helps with pain relief, alcohol withdrawal, and regulating thyroid and adrenal gland hormones.
7. Threonine:
   20 mg – Helps with the production of collagen and elastin for healthy skin.
8. Tryptophan:
   5 mg – Helps control several functions in the central nervous system and contributes to the production of niacin.
9. Valine:
   24 mg – Helps stimulate muscle growth, produce energy, and maintain physical stamina, and also supports the central nervous system in stressful times.

* (The guidance above may change over time as research continues. The mg represents the US RDI per kg body weight, and this will be affected by your age and weight, so please use the above as a guideline only.

WHEN IS TOO MUCH?

Our bodies efficiently dispose of excess nitrogen, so protein intakes above the daily recommendations are believed to be safe.

Some researchers have postulated that excess protein intake can accelerate aging, but no human studies support this claim. It has also been suggested that habitual high intake may contribute to osteoporosis, but this seems unlikely based on current evidence in the United States, where intakes are substantially above requirements. There is no firm evidence that this is harmful. 

More about protein and protein intake in our Protein Guide. 

Excessive intakes are considered over 35% of total calories, and symptoms of protein poisoning include an upset tummy, headaches, mood changes, tiredness, low blood pressure, and low heart rate. High-protein diets may also worsen kidney function in people with kidney disease.  

Find out more about the amino acid profiles in protein supplements, what you should be looking for, and also find out more about some of the benefits of having protein and the different types of protein that are available.