Stop the clock: How to slow down the ageing process and ward off disease

Mitochondrial dysfunction is a hallmark of ageing, but it isn't inevitable

Scientists have defined 12 hallmarks of ageing. There were nine to start with, but they have helpfully found another three.

Ageing, for those of us who live long enough to enjoy the experience, is inevitable. But accelerated ageing, the type that precipitates the premature arrival of chronic diseases associated with the process, is not.

One of the major and most modifiable hallmarks of ageing is mitochondrial dysfunction. Closely linked to our internal body clock, mitochondrial dysfunction is one of the cabal of twelve that is largely within our control.

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What are mitochondria?

The mitochondrion is the energy-producing centre of the cell. The energy produced is in the form of adenosine triphosphate (ATP), which is created from the breakdown of nutrients. The process is called cellular respiration.

Reduced mitochondrial function is a normal part of the ageing process. But when reduced function goes beyond what is normal, and the mitochondria fail to produce sufficient energy to keep everything working, the cell becomes damaged and the body is left vulnerable to disease. The mitochondria are unable to handle oxidative stress and regulate cell function.

Not surprisingly, mitochondrial dysfunction can lead to chronic fatigue and brain fog. Most affected are those systems and organs that require higher amounts of energy: the muscles, heart and brain. Cardiovascular disease, heart failure, Alzheimer’s, Parkinson’s, diabetes and cancer are all associated with mitochondrial dysfunction.

The clock strikes

Everything in life is cyclical and we are all bound by the rotation of the Earth. That includes the mitochondria, which use nutrients differently, according to the time of day and in accordance with the circadian clock.

The circadian clock, present in almost every species, ticks with almost 24-hour precision, in alignment with the rotation of the Earth. Sometimes called the ‘master’ clock, it is located within the hypothalamic suprachiasmatic nucleus (SCN) of the brain.

There are peripheral clocks ticking in almost every cell of the body and they feed back to this master clock.

These ‘local’ clocks regulate mitochondrial function. The mitochondria constantly change their shape from tubular (fusion) to fragmented (fission). In healthy people, these two activities (aka the mitochondrial dynamics) are equally balanced.

If the clock malfunctions, the mitochondria can lose their circadian rhythm and balance and become disordered. There is excessive production of reactive oxidative species (ROS), or free radicals. Energy production is disrupted.

What causes this malfunction?

Disrupt the clock and you disrupt cellular metabolism. This is something seen in shift workers, who have a much higher risk of metabolic disorders, including obesity, diabetes, and insulin resistance. Jet lag and social jet lag (staying up late, using electronic devises at night) also disrupt the clock and can ‘critically influence physiological homeostasis.’

Ageing is associated with deterioration of circadian rhythms. In later life we wake earlier, and we wake during the night. There is a reduction in the deeper states of non-REM sleep. Even middle-aged adults can experience age-related changes in sleep patterns. Why this occurs is largely unknown.

But we do have a certain amount of fight-back. There is ‘mounting evidence’ that dietary interventions have a powerful effect on the circadian clock and the metabolic pathways under its control.