Lysine is one of numerous amino acids that the body needs for growth and tissue repair. It is classified as one of the nine "essential" amino acids because you need to get it from outside sources such as foods or supplements – your body can't make it on its own.
As an amino acid
, it is found in a host of foods and is not normally deficient in the diet. Many foods supply lysine
, but the richest sources by far include red meats, fish, and dairy products (milk, eggs, cheese). Vegetables, on the other hand, are generally a poor source of lysine, with the exception of legumes (beans, peas, lentils).
Of all the amino acids
, lysine is the most sensitive to the effects of food processing, such as dry heat. The amount of protein available in legumes and other sources of lysine can be significantly reduced if they have been toasted or roasted.
While many people satisfy their need for lysine through dietary sources, supplements are now popular for treating and preventing specific ailments as well.
Supplements come in various forms: tablet, powder, liquid, and capsule.
Function; Why it is Recommended
Like all amino acids
functions as a building block for proteins. It is also a key player in the production of various enzymes, hormones, and disease-fighting antibodies
. It is necessary for proper growth and helps form collagen
which comprises bone cartilage
and connective tissues.
Researchers are exploring the value of lysine
supplementation and the consumption of lysine-rich foods for lowering cholesterol
, improving athletic performance, and enhancing recovery after surgery. Because Lysine helps repair tissue, it is a good supplement for anyone recovering from surgery and injuries.
Lysine is helpful in lowering triglycerides
and as an anti-aging factor. It is involved in the structural repair of damaged blood vessels.
Recently it has been shown that L-Lysine can inhibit the growth of the herpes
virus. Herpes virus requires many proteins with the amino acid arginine
, and lysine competes directly with arginine in many of these processes. This competition is thought to slow down the growth of the herpes virus. While high doses (500-1500 mg/day) are beneficial during the suppression of viral growth, lesser amounts should be taken, if taking on an on going basis to prevent an amino acid imbalance problem.
At the time of writing there is no official RDA for lysine
. It is estimated, however, that the daily requirement for an adult is approximately 12mg per kilogram (2.2lb) of body weight.
Side-Effects; Counter-Indicators and Warnings
Side-effects are rare with lysine
supplements, although a few cases of abdominal cramps
have been reported with very high doses (more than 10gm per day).
In very large doses (10 to 30gm per day), lysine
increases the toxicity of aminoglycoside antibiotics, such as gentamicin, neomycin, and streptomycin.
References & Further InformationA comprehensive list of foods and their lysine/arginine content can be found here