Ageing We Can See - Or Can We?
Getting older is something no human can avoid, but we can influence our biological ageing rate. The best example of visible ageing is our own skin. Simply compare the quality of the skin of the face or the back of the hands compared to the quality of the skin under our armpits or inner thighs; this skin can be as smooth as the skin on a "new babies bum" whereas the facial skin is more wrinkled and marked.
The important point of the video is that the damage when we are young is invisible to the naked eye, and that there are no symptoms (pain, itching and so on). We are unaware of the cell damage being done, and it is the accumulation of "invisible" cell damage over decades that results in skin aging as we get older.
What About Our Insides?
Skin damage is caused by our suns "ionizing" UV radiation. We can't see our insides but over time the cells that make us (about 60 to 80 trillion cells depending on our size) are damaged by "ionizing molecules" of various types like free radicals, reactive oxygen species, super oxides, peroxides and Advanced Glycation End Products (AGE's). Cells are being damaged every single millisecond, this is unavoidable; but to manage this our cells also have wonderful repair mechanisms. Even so, over time a cell can be damaged to the point where it is too dysfunctional. At this time it may be killed by the immune system, or commit suicide.
This is a good thing we don't want bad cells to survive that aids disease and ageing. Dead cells need to be replaced, so another cell of the same type divides into two to replace the cell that has been lost. So far so good, except that errors can and do occur during the process of cell division, and damage already accrued in the cell may be inherited by the new cell. As a tissue cell divides over and over gain there is a risk that the errors and damage can accumulate and be replicated. This could eventually result in the accumulation of dysfunctional cells, resulting in ageing and disease.
To combat this nature has provided us with a fail safe system. The number of times a cell (a liver cell, brain cell, virtually any type of mature fully defined cell) can divide is strictly limited by "telomeres" at the end of the cells chromosomes. Once that limit is reached the cell survives but can longer divide. These are called "senescent" cells, the more of these that our tissues contain "the older our tissue is". Our bodies are amazing. As these senescent cells accumulate in a tissue and dying cells need to be replaced adult "stem cells" come to the rescue. Stem cells can move around the tissue, divide to replicate themselves, and give birth to a brand spanking new tissue cell. As with normal cell division, adult stem cell division errors can and do occur. Unlike normal cell division there is no limit (fail safe system) as to the number of times an adult stem cell can divide. The more times stem cells divide the greater the risk of mutation errors. Some research has shown that the number of adult stem cell divisions that occur in a particular tissue is directly related to risk of cancer forming in that tissue. It is suspected that this cell "ageing" process is responsible for up to 80% of tissue tumours.
Can We Slow The Ageing Process?
Yes we can by simply slowing the rate of cell damage and division. We can slow the rate at which our skin ages by reducing our exposure to the Sun. But its a double edged sword; we need some sunshine to stay healthy (Vitamin D) but too much accelerates skin aging. It's all about balance and this is particularly important with food. It has been known since 1934 that limiting food consumption to just enough to maintain a healthy lean body weight in laboratory rats, could increase their lifespan by twofold. We now know that food consumption also affects the lifespan of primates, see the "The Tale of Two Monkeys" blog HERE. The over consumption of food causes cell damage and cell damage is ageing. This is due to the overproduction of "ionising" molecules as a result of normal metabolism of food.
The degree of cell damage is also affected by what mix of foods we eat, as well as when we eat (cell repair mechanisms need times of rest to do their job) as well as stress. Emotional and physical stress causes molecules to be released within our bodies that cause cell damage and inflammation.
As with the Sun, food is double edged sword, we need it to survive but too much increases the rate of ageing, and the risk of age related disease.
A quick word on exercise, it's good for us; but we cannot "run off" a bad diet, and exercise is the least effective practice to manage weight.
Understanding and implementing balanced food consumption, rest, and stress, significantly increases our chances of adding more years to our lives and putting more life into those years.