Lysine is an essential amino acid.  It is a described as a  “ base, as are arginine and histidine”. It is one of those fundamental building blocks on which life itself is based.  Animals are made of lysine in various forms, but so are plants and bacteria.  Human beings obtain lysine by eating animals or animal by-products or eating plants.  But plants and bacteria, which also use lysine, obtain it from a long complex process in which it is synthesized from aspartic acid, minerals, water and a large number of enzymes.

Collagen is dependent on lysine.  Elastin is dependent on lysine.  Allysine, which is a derivative of lysine, is used in the production of both elastin and collagen. Lysine is used to build hormones and even enzymes in the body. 

Despite some rather confusing research which appears to indicate lysine has some antiviral or antibacterial role, it doesn’t.  It can repair the damage, but it does not actively fight against disease.  The amino acids are the building blocks of life. 

Most of the anti-viral, anti-bacterial and anti-fungal activity is found in plants and is obtained via other substances such as the vitamins or polyphenols.

Functions

 

Collagen  - is the main structural protein in the extracellular space in the various connective tissues in animals. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content.  Collagen is formed of elongated fibrils.  It is mostly found in fibrous tissues such as tendons and ligaments. It is found in the artery walls, skin, intestines and the uterus.  It is also abundant in corneas, cartilage, bones, blood vessels, intervertebral discs and the dentin in teeth.  Collagen constitutes one to two percent of muscle tissue, and accounts for 6% of the weight of strong, tendinous muscles.  So as you can see lysine is pretty essential to the workings of our bodies.  Collagen has an unusual amino acid composition and sequence:

• Glycine is found at almost every third residue.
• Prolinemakes up about 17% of collagen.

Collagen contains two uncommon derivative amino acids not directly inserted during translation. These amino acids are found at specific locations relative to glycine and are modified post-translationally by different enzymes, both of which require vitamin C as a cofactor.

• Hydroxyproline is derived from proline
• Hydroxylysine is derived from lysine.

Thus to make collagen you need glycine, proline, vitamin C and lysine.

Elastin  - is, as its name suggests,  a highly elastic protein in connective tissue.  It enables many tissues in the body to resume their shape after stretching or contracting and helps skin to return to its original position when it is poked or pinched. The total elastin ranges from 58 to 75% of the weight of the dry defatted artery in normal [canine] arteries, for example,  so you can see it has a multiplicity of uses.  Elastin is also an important load-bearing tissue in the bodies of vertebrates and used in places where mechanical energy is required to be stored.
“A minimum of 48% of the arterial load is carried by elastin, and a minimum of 43% of the change in stiffness of arterial tissue is due to the change in elastin stiffness”

A substance called elastic fibre is used in the body and it is composed of ‘extensively cross-linked’ elastin, and a ‘fibrillar component’ – fibrillin!  Both these are made of simple amino acids such as glycine, valine, alanine, and proline.

In effect, Elastin is produced by the actions of the enzyme lysyl oxidase on lysine in the extracellular matrix and is essential in the crosslink formation that stabilizes collagen and elastin.

Calcium absorption - Lysine also appears to play a major role in calcium absorption.

Lysine deficiency

One way of seeing what lysine does is also to look at what happens when people [or animals] suffer from lysine deficiency.

Anger and stress - In one study it was demonstrated that lysine deficiency led to “a pathological increase in serotonin in the amygdala”.  The amygdala governs the emotions and a deficiency resulted in stress, anxiety and anger.  Other human studies have also shown correlations between reduced lysine intake and anxiety. A population-based study in Syria, for example, which  included 93 families whose diet was primarily grain-based and therefore likely to be deficient in lysine, came to the same conclusions, lysine deficiency causes anger and stress.

Impaired immune system - Lysine deficiency also causes an impaired immune system.  And this is serious, truly serious.  This has been shown in humans, but has also been shown to be true in chickens!  What has not yet been studied is whether an overdose causes excessive immune reactions.  This is a serious point, as overdose can often be as bad and occasionally worse than deficiency.

For reasons which completely elude us, for example, lysine is manufactured and then added to animal feed that is fed to poorly farmed intensively reared chickens and cattle.  These poor animals then – because of the conditions in which they are being kept, become sick and are fed antibiotics.  But feed laced with manufactured  lysine [or no lycine!] can’t be helping. 

Go organic and free range and start to give animals a decent life!

Macular degeneration and blindness – our eyes and colour vision depend on lysine

Thus to call lysine essential is perhaps rather underestimating its importance, not just essential but crucial!!

Sources of Lysine in Food

We have provided an observation derived from Dr Duke’s phytochemical database that shows the plants that have lysine.  The table below shows the other foods and is ordered by nutrient content. 

It comes from the USDA Nutrients database, which produces a list some 100  plus pages long and which also has a fair amount of repetition, caused by the fact that each product has to have labelling whereas we are looking for broad guidelines we can use in cooking and preparing balanced meals. 

It also includes processed food, which we have excluded. We have included no vegetables generally, as these are in Dr Duke’s list.

Overall in order to get adequate lysine input, a vegetarian needs to concentrate on eggs, fish and hard full fat cheese.  A meat eater has a very easy time, unless of course they have become allergic to gelatine.  In this case, they might be better to go vegetarian and eat more oily fish.