What is protein crosslink?

All the proteins in our cells are replaced quite regularly because they get damaged. But some of the proteins outside our cells aren’t replaced or only very slowly. The overall structure of our tissues is a network of structural proteins linked together in regular rows and columns to give both support and elasticity where it is needed. This elasticity diminishes with age, largely as a result of the accumulation of additional linking between adjacent strands of protein in the network called protein cross linking. You can think of this as the handcuffing together of adjacent proteins: crosslinking prevents them from going their own way to carry out their function.

How does the damage set in?

Most of the energy we get from bread, cereals, pasta and many other foods is broken down into simpler sugars like glucose for delivery to our cells through the blood. Unfortunately, in addition to being a vital cellular fuel, glucose is also a substance that can cause damage by randomly reacting with proteins in a process called “glycation.” Sometimes glycation can lead to two strands of protein getting linked together into a “crosslink.” Cigarette smoke and fried foods also contribute to crosslinking. The process happens gradually, so that crosslinking accumulates over the years on the longest-lived proteins which do not get recycled very often. Crosslinking reduces the flexibility, elasticity, and functionality of the proteins.
When cross-linked, artery walls become hard, brittle and less able to pulsate. This prevents the arteries from cushioning the pounding pulse as the blood leaves the pumping chamber of the heart, causing a gradual rise in blood pressure as we age and damage to organs as the pulse pounds harder and harder on them.

Resultant diseases

The chemical modifications of glycation and crosslinking can initiate harmful inflammatory and autoimmune responses. More importantly, the rise in blood pressure and loss of cushioning caused by crosslinking in the arteries causes damage to the kidneys and brain as the pulse hammers harder and harder on them, increases the risk of suffering a stroke, and accelerates atherosclerosis in the arteries themselves.

Solution

Research is on for drugs or substances that can break these cross links, restoring the supple elasticity of youth to aging arteries. Certain substances have been identified as particularly effective in breaking certain types of these links, but not yet for the most important kinds – the ones that add the most to the stiffening of the arteries.