What is Lysine?
L-lysine, commonly known as lysine, is one of the indispensable, essential amino acids for humans. Lysine is not produced in the body and thus we have to obtain it from dietary sources or as a supplement. Lysine is one of the amino acids that constitute proteins.
Health Benefits of Lysine
Lysine is used for the prevention and treatment of herpes: cold sores, (caused by herpes simplex virus-1) and genital herpes (caused by herpes simplex virus-2). Lysine may also increase absorption of calcium and reduce excretion of calcium, and possibly lower the severity of osteoporosis. Lysine is also the substrate for the synthesis of amino acid carnitine, which in turn is an important substrate in the process of energy generation. Other lysine benefits include improving the immune system and promotion of overall well-being.
There is also a hypothesis that suggests an association between consumption of foods high in lysine and low in arginine and lower risks of incidence of Alzheimer’s disease.
Lysine, Arginine and Herpes
L-arginine is an amino acid required by the herpes virus for its reproduction. And the mechanism by which lysine helps in the treatment of cold sores and genital herpes is by reducing the availability of arginine for the herpes virus. Both lysine and arginine compete for absorption in the intestine, re-absorption in the kidney and transport vehicles to the cell. Thus, a high lysine to arginine ratio allows lysine to outcompete arginine and starve the herpes virus the amino acid required for its replication. Besides, lysine increases the breakdown of arginine by stimulating the enzyme arginase, an enzyme that breaks down arginine.
Food Sources High in Lysine Content
Lysine is found in high amounts in high protein foods. It is generally low in cereal foods, except in wheat germ. Based on the USDA Nutrition Laboratory analysis of common foods in the US, high lysine foods include seal and whale meat, soy protein isolate, egg (the white part), cod, and parmesan cheese.
On average, a Western diet, for adults, provides 6 – 10 grams per day.
The tables below show the top highest lysine foods (Table 1) of all food categories and also top highest lysine food sources in each food category (Tables 3 - 6).
Table: List of foods high in Lysine content.
| Lysine food source | Lysine content (g/100g of edible food portion) |
|---|---|
| Seal, bearded (Oogruk), meat, dried (Alaska Native) | 6.69 |
| Whale, beluga, meat, dried (Alaska Native) | 6.31 |
| Fish, cod, Atlantic, dried and salted | 5.77 |
| Egg, white, dried | 5.52 |
| Soy protein isolate | 5.33 |
| Egg, white, dried, powder, glucose reduced | 5.08 |
| Seal, bearded (Oogruk), meat, partially dried (Alaska Native) | 5.05 |
| Fish, whitefish, dried (Alaska Native) | 4.77 |
| Egg, white, dried, flakes, glucose reduced | 4.74 |
| Soy protein concentrate, produced by acid wash | 3.93 |
| Cheese, parmesan | 3.84 |
| Smelt, dried (Alaska Native) | 3.69 |
| Protein powder soy based (beverage) | 3.55 |
| Gelatins, dry powder, unsweetened | 3.46 |
| Egg, whole, dried | 3.34 |
| yeast (leavening agent), baker's, active dry | 3.28 |
| Tofu, dried-frozen (koyadofu) | 3.16 |
In the next page are vegetarian foods high in lysine.