Lysine is found in most protein food sources but is not as readily available from the grain cereals or peanuts. Lysine is particularly high in fish, meats, and dairy products and higher than most other amino acids in wheat germ, legumes, and many fruits and vegetables. Lysine has many functions. It is concentrated in muscle tissue and helps in the absorption of calcium from the intestinal tract, the promotion of bone growth, and the formation of collagen. Collagen is an important body protein that is the basic matrix of the connective tissues, skin, cartilage, and bone. Vitamin C is needed to convert lysine into hydroxylysine, which is then incorporated into collagen. Lysine is also metabolized by transaminase enzymes in the liver; its metabolism depends on vitamins B6, B3, B2, and C and on iron and glutamic acid. Dietary needs for lysine are estimated to be 750–1000 mg. daily. A deficiency may contribute to reduced growth and immunity along with an increase in urinary calcium. This latter fact suggests that adequate lysine may help prevent osteoporosis through better absorption and utilization of calcium.
Lysine has recently become popular in the prevention and treatment of Herpes simplex infections. Though research has been somewhat contradictory, most studies claimed good success, particularly for cold sores (herpes type 1). Nearly 80 percent of patients studied believed that taking 1–2 grams of L-lysine each day helped them reduce outbreaks and symptoms. The percentage was lower for genital herpes (type 2), a finding that my clinical experience supports. For people who seem to respond to lysine treatment, recent research suggests that an effective dose is 1500 mg. a day (usually 500 mg. three times daily) during an infection and 500 mg. daily when no symptoms are present. Please remember, though, that recurrent herpes outbreaks can be a complex problem relating to stress, weakened immunity, a diet too high in acid-forming foods, and nutritional deficiencies and that lysine therapy is not a substitute for dealing with these factors.
Another aspect of herpes infections involves the ratio of lysine to arginine in the diet. A higher lysine to arginine ratio seems to help many patients reduce the incidence of herpes outbreaks. Animal proteins provide a ratio of about 3 or 4:1, while vegetables are closer to a 1:1 ratio.
Thus, in herpes prevention and treatment, avoiding arginine-rich foods and eating more lysine-rich foods may be helpful.
Interestingly, recent research has suggested that therapy using L-lysine and L-arginine (see later discussion) together is useful and possibly even better than the arginine/ornithine combination in stimulating growth hormone, muscle building, weight loss, and immune support. A dosage of 500 mg. twice daily, or 1000–1500 mg. taken before bed, of each amino acid would help in these functions.
Lysine has little or no toxicity. Not uncommonly, when one stops therapy for herpes, he or she has an outbreak. Lysine is fairly safe, although I do not believe that any amino acid should be used over a long time without a break or without supporting the diet with the other amino acids as well.