Biologically speaking, we can define aging as the overlap of a progressive series of alterations in cells and tissues.
Such damages are the cause of the increased disease and death risk.
We can simply represent such concept with the following formula:
A (aging) = D(damages) = R (repair)
This means that if every suffered damage is followed by a correct repair of cell and tissue alterations, the possibility of a physiological aging is very high.
Normally, the most damaged parts of our organism are the following:
- Neuronal and cell membranes (like membrane receptors)
- Muscle and skin proteins
- Hormones and neurotransmitters
- Polynsaturated fat acids and lipids in general.
Damage causes can be resumed as following:
- Oxygen and nitrogen free radicals (oxidative stress)
- AGEs and ALEs (glycation and lipoperoxidation)
- Heavy metals (lead, mercury, aluminum, cadmium, etc.)
- Environmental pollution (ex.: pesticides, food additives, electromagnetic pollution)
- Sub-clinical microbial infections.
Free radicals are molecules mainly deriving from oxygen and nitrogen. They are very unstable because they lost part of themselves, that is one or more electrons. This is why they try to stabilize as soon as possible by capturing the missing electrons.
The molecules that supply electrons to free radicals are than oxidized losing their functionality.
There are many oxidized molecules, the most important of which being the following:
- Malondialdehyde (MDA): it is the result of lipid oxidation of cell membranes.
- 8-hydroxydeoxyguanosine (8OHDG): it is the result of DNA oxidation.
- Oxidized bilirubin
- Azelaic acid and glutarate: they are the result of the cellular membrane damage.
Glycation consists of the creation of molecules called AGEs.
Such AGEs are the result of the union between organism’s sugars and proteins, as if proteins were covered by a substance similar to caramel. And if proteins are located on cellular membrane, the entire cell will be covered by such substances.
As it happens in oxidized molecules, also glycated cells and proteins lose their functionality.
On the other side, there are the repair factors which are necessary to combat both damage causes and effects. Here are some of them:
- Enzyme antioxidants (glutathione, catalase, superoxide dismutase)
- Non enzyme antioxidants (A, C, E vitamins, bilirubin, albumin)
- Heavy metals chelating agents.
But what does it happen when D becomes higher than R?
There are the first generic symptoms described as vague and non-specific (MUS or medical unexplained symptoms).
At this stage it can easily happen that any routine diagnostic exam doesn’t point out important alterations.
These MUS are nearly 40; here are some of them:
- Continuous tiredness and fatigue
- Insomnia and awakenings during the night
- Continuous sleepiness
- Anxiety and apathy
- Hunger during evening or night
- Carbohydrate craving
- Heartburns, nausea, abdominal swelling
- Constipation or diarrhea
- Cold hands and feet
- Night sweat
- Difficulty in enjoying positive events
- Libido decreased.
But how do damage causes produce such symptoms?
To answer this question we have to better explain the concept of stress.
by Giorgio Crucitti