What Are Amino Acids?

Medically Reviewed

Called the "building blocks of life," amino acids can be obtained in healthy amounts by eating foods that contain them.

Amino acids are compounds that combine to form proteins.

Naturally found in our bodies, they're often referred to as the "building blocks of life."

Amino acids are needed for the production of enzymes, as well as some hormones and neurotransmitters.

They're also involved in numerous metabolic pathways within cells throughout the body.

You can obtain amino acids through the foods you eat.

After your body digests and breaks down protein, amino acids are left in the body to help do the following:

  • Break down food
  • Grow and repair body tissue
  • Provide a source of energy
  • Perform other bodily functions

Types of Amino Acids

Amino acids can be placed in three different groups:

Nonessential amino acids: These are produced naturally by your body and have nothing to do with the food you eat.

The following are examples of nonessential amino acids:

  • Alanine
  • Asparagine
  • Aspartic acid
  • Glutamic acid

Essential amino acids: These can't be produced by the body and must come from the food you eat.

If you don't eat foods that contain essential amino acids, your body won't have them. The following are essential amino acids:

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

It isn't necessary to eat essential amino acids at every meal. You can get healthy amounts by eating foods containing them throughout the day.

Animal-based foods such as meat, milk, fish, and eggs provide essential amino acids.

Plant-based foods such as soy, beans, nuts, and grains also contain essential amino acids.

Over the years, there has been controversy about whether vegetarian diets can provide adequate amounts of essential amino acids.

Many experts believe that while it may be harder for vegetarians to maintain an adequate intake, they should be able to do so if they follow the American Heart Association's guidelines of 5 to 6 servings of whole grains, and 5 or more servings of vegetables and fruits, per day.

Conditional amino acids: These are usually not essential to everyday living but are important when you're sick, injured, or stressed.

Conditional amino acids include:

  • Arginine
  • Cysteine
  • Glutamine
  • Tyrosine
  • Glycine
  • Ornithine
  • Proline
  • Serine

When you're ill or injured, your body may not be able to produce enough conditional amino acids, and you may need to give your body what it needs through diet or supplements.

Talk with your doctor about the safest way to do this.

Can Amino Acids Be Harmful?

When your body has too much of amino acids, the following effects can occur:

  • Gastrointestinal distress, such as bloating
  • Abdominal pain
  • Diarrhea
  • Increased risk of gout (buildup of uric acid in the body, leading to joint inflammation)
  • Unhealthy drop in blood pressure
  • Changes in eating patterns
  • Need for your kidneys to work harder to maintain balance

Most diets provide safe amounts of amino acids.

Still, talk with your doctor if you plan to follow a diet that's very high in protein or one that includes amino acid supplements for any reason — including any supplements taken to support intense athletic training.

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