The Toll of Neuro-Degenerative Disease

Ageing is characterised by a progressive decline in the efficiency of cellular function and the increased risk for disease and death – not a happy future!

At the very heart of the ageing process is the balance between cellular stressors and our ability to maintain biochemical balance and avoid cellular damage in the face of those stressors.

The “free radical theory of ageing” suggests that reactive oxygen molecules (free radicals) produced during cellular energy metabolism have damaging effects on all cells and across all tissue in the body – causing cumulative damage over time that ultimately results in ageing, dysfunction, and death. 

Each of our cells has a built-in system of defence to protect from damage by cellular stressors – called the Nrf2 pathway. In the ageing (healthy) brain, as well as in the cases of several neurodegenerative diseases, there is a dramatic decline in the body’s ability to mount a robust defence against cellular stressors, which increases the vulnerability of the brain and the entire nervous system to damage.

For example, oxidative damage to the DNA and cell membranes has been detected at levels more than 10 times higher in the brains of Alzheimer’s disease patients and 17 times higher in the brains of Parkinson’s disease patients compared to healthy subjects. Brain neurones and nerve cells are comprised of lipids (fats) that are highly susceptible to attack by free radicals.

High levels of damaged fatty acids (damaged proteins) have been identified in ageing brains and associated with cognitive deficits. In the brain, such damage to fatty acids and proteins is known to set off an immune/inflammatory response that often leads to further cellular damage when prolonged. Elevated levels of inflammatory cytokines leads to a vicious cycle of further cellular damage that propagates through a chain reaction across tissues.