While all this is going on it is possible for a variety of reasons for damage to occur to the cell membrane, to aspects of the cytoplasm or to the essential DNA controls. This is because while all the industrious activity is continuing round the dock, a variety of hostile factors are also present, including changes m temperature, radiation damage, free radical activity (a normal byproduct of oxygen metabolism), possible bacterial and viral assault, nutritional deficits, toxic accumulation and a host of as yet unknown hazards including the possible influence of the mind (negative emotions, poor stress coping etc.) on defensive and repair capabilities. Thus the factory in which protein is being manufactured also has a need for an efficient waste disposal system and a well-organized maintenance crew and fire brigade. In good health it has all of these in abundance.
These homoeostatic (self-regulating) functions are provided by a host of different enzymes and antioxidant substances which act to protect against toxicity and to deactivate free radical activity and repair damaged tissues, including DNA, when this is necessary. However, under adverse conditions the maintenance crew (enzymes mainly) and fire brigade (antioxidant and enzymes) can themselves be damaged and compromised and therefore become inefficient in their repair and defense functions.
This could well be the case where a diet and/or lifestyle provides an excessive quantity of free radical activity, such as derives from a diet high in fats and sugars, or an intake of excessive alcohol, tobacco smoke, environmental pollutants etc., especially when such exposure is also combined with a diet poorly supplied with anti oxidants such as are found in fresh fruits and vegetables - vitamins A, C, E etc.
All of our cells' manufacturing and defensive functions including the copying onto RNA from DNA of the master plan, the sending of the RNA to the cytoplasm and the assembly and manufacture of the new protein, requires energy, and this is constantly being provided in cells by use (burning) of fats and sugars. In the cytoplasm of our cells lie a host of miniature energy production sites called mitochondria. These bum food (fats etc.) in the presence of oxygen in order to meet the energy needs of the cell. In the manufacturing process by-products called free radicals are formed. These have the potential for causing damage unless rapidly 'switched off' or 'quenched' by antioxidant nutrients (Vitamins A, C and E) or enyzmes (such as super oxide dismutase).
The rate at which our cells operate and use energy determines what is called our basic metabolic rate (BMR) which seems to be a major feature in understanding ageing processes, since slow BMRs are associated with longer life and speedy BMRs with shorter life expectancy. The BMR to a large extent decides our core temperature, another feature of life expectancy (low core temperature = longer life expectancy) and this is itself influenced by features such as hormonal balance. I will explain this more thoroughly in later chapters.
If there are problems in the nucleus of a cell due to damaged DNA, or if energy levels are poor and transportation of RNA or raw materials becomes sluggish, or if anything at all goes wrong in the protein synthesis (manufacturing) process, or should the cell membrane become inefficient in selectively allowing the passage of only desirable substances, then the cell will become inefficient, and start producing faulty material. It might also become unable to cleanse, repair and reproduce itself and would then ultimately perish.