L-lysine is commonly referred to as lysine and is an essential amino acid, which means it’s essential for human health. However, the body can’t synthesise it, so it must be obtained from food or from supplementation. Like all amino acids, it is a building block for all protein within the body. It was first isolated in 1889 from the milk protein, casein.
Cold sores and more
Lysine is particularly useful for the treatment and prevention of herpes simplex, the virus that causes cold sores and genital herpes. The herpes simplex virus requires the amino acid arginine to replicate and cause symptoms. Lysine competes with arginine for absorption into cells and tissues, thus limiting the amount of arginine available for the virus to use to replicate itself. In this way, lysine works by cutting off the food supply to the virus.
In a study of 41 patients it was found that oral ingestion of 1248mg a day of lysine decreased the recurrence rate of herpes simplex attacks, thereby rendering it an effective preventative. In another study, 52 subjects took 1000mg of lysine three times daily over a period of six months. It was found to not only decrease recurrence rates but also significantly diminish the severity and healing time of symptoms.
Heart health
Lysine is also effective in helping to reduce the risk of atherosclerosis through its ability to bind to lipoprotein(a). High levels of Lp(a) in the bloodstream are associated with a high incidence of coronary artery disease. When a lesion occurs in the wall of a blood vessel, Lp(a) binds to the damaged blood vessel and begins to form an atherosclerotic plaque. The sites where Lp(a) binds to the blood vessel are known as lysine binding sites, a discovery by Linus Pauling that won him a Nobel Prize.
Pauling found that increasing the amount of lysine circulating in the blood caused Lp(a) to bind with the lysine rather than binding to the blood vessel wall and causing an atherosclerotic plaque. It was also found that lysine can cause Lp(a) to be released from the arterial wall and may even help dissolve the plaque.
When your coronary arteries are narrowed or blocked, oxygen-rich blood can’t reach your heart muscle. This can cause angina or a heart attack. Dr Linus Pauling also reported on several cases of angina being relieved by lysine.
Bone strength
Lysine improves the ability of your body to absorb, regulate and utilise calcium, thus promoting growth and maintenance of bones. Studies on the effect of lysine on the prevention of osteoporosis found that supplementation significantly increased the intestinal absorption of calcium while decreasing the renal excretion of calcium in both healthy women and those with osteoporosis.
Lysine also helps to form collagen, thereby helping to strengthen your bone cartilage and connective tissue such as ligaments, joints, skin and teeth.
Lysine is required for the synthesis of carnitine, an amino acid involved in, among other things, fatty acid metabolism. Lysine also helps to build muscle protein and is useful in supporting the health and recovery of lean muscle mass. It is therefore beneficial in recovering from surgery and sports injuries.
As research emerges, it appears lysine may be even more versatile than previously thought. Certain studies have suggested it may play a role in helping with symptoms of asthma, migraines, nasal polyps and post-episiotomy pain.
Food sources
The best food sources include meat, particularly red meats, legumes, cheeses (especially parmesan), poultry, nuts, eggs and certain fish such as cod and sardines.
A deficiency of lysine is linked to a variety of symptoms such as fatigue, inability to concentrate, irritability, dizziness, appetite loss, decreased antibody formation, decreased immunity, bloodshot eyes, slow growth, hair loss & reproductive problems. However, incidence of marked lysine deficiency in the diet is rare in developed countries such as Australia.
Strict vegetarians who consume limited dairy and legumes as well as athletes who undertake strenuous exercise may be at increased risk of deficiency.
Cold sore treatment
For prevention of cold sore outbreaks take 1g of lysine a day and, if outbreaks occur, the dose should be increased to at least 1g taken three times daily. When deciding on which brand of lysine to take, try to find one that is manufactured from natural L-lysine sourced from foods rather than a synthetic version that has been manufactured in a laboratory; and, if possible, one that also contains other beneficial nutrients such as zinc, vitamin C and bioflavonoids. These compounds work in synergy with each other, being more effective in your body when taken together.
There are no known adverse effects when taken within the recommended dose range. Doses greater than 10–15mg may cause nausea, vomiting or diarrhoea. High-dose lysine supplementation should be used with caution if you have high blood levels of calcium. Caution is also advised if you have liver or kidney disease.
Versatile lysine
- Prevents and treats herpes virus outbreaks
- Reduces risk of coronary artery disease
- Improves calcium absorption
- Helps to form collagen
- Required for carnitine synthesis
- Aids muscle recovery
Saskia Brown is a qualified naturopath. She is currently practising in Neutral Bay specialising in weight loss, allergies and asthma. W: www.saskiabrown.com.
