Amino Acid Supplements Rarely Needed

Q:  I heard that taking amino acids are good for you. Should I be taking them?

A:  Amino acids are the building blocks that make proteins. Proteins are essential for every function of the human body, from the muscles to the blood cells to digestion.

Certain amino acids are considered "essential" because they can't be made by the body so must be obtained in the diet. (The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.)

Average Americans get adequate amino acids from their usual diet. They are in foods that one considers protein-rich: meats, fish, dairy, eggs, nuts, seeds, and legumes like black beans. Animal sources of protein (like meat, eggs and diary) are more concentrated in essential amino acids than vegetable sources (like soybeans).

If you have enough of the 9 essential amino acids, your body can manufacture the remaining 11. Some beans do have all the essential amino acids, but it's hard to get enough from beans alone, unless you eat a lot of them.

So, in one manner, you are already "taking" amino acids whenever you eat a food with protein. But I'm sure you meant "taking" them in the form of a pill, which you can easily get anywhere they sell other "nutritional supplements." And, without even knowing in what way you may have been told that amino acids are "good for you," I would have to say, no, you shouldn't bother to take them in as a pill.

The reason I say that is not only to save you a few dollars, but because there is a (probably very small) risk with anything manufactured and sold as a supplement. The government does not require supplement manufacturers to prove that their products are safe, let alone effective for their health claim.

The manufacturer does not even have to prove that their product contains what is written on the label! For example, one study of 59 preparations labeled "Echinacea" found that half of the products did not actually contain Echinacea. More worrisome, supplements could be contaminated with something else like other herbs, pesticides, or prescription drugs.

Sometimes it may be useful to take a supplement, even with its unregulated status. Those times are when the supplement has generally been shown to be helpful for a specific problem or health concern. In the case of amino acids, however, there is no proven benefit to taking them in the form of a pill.

Julie L. Mitchell, MD, MS, is an Associate Professor of Medicine at the Medical College of Wisconsin. She practices at the Froedtert & The Medical College of Wisconsin General Internal Medicine Clinic - East. Her column appears in the Milwaukee Journal-Sentinel.