ABSTRACT
A living animal is a complex, improbable organisation which has to defend its high degree of order against forces of nature tending to equalise it with its environment by converting it into a simple, random conglomeration of matter. In addition, predators and parasites are in constant readiness to destroy a weakening organism. Lastly it may not be to the advantage of the species to let individuals outlive their usefulness. When old animals become unproductive competitors for limited natural resources, nature, in its unsentimental way, may take measures to eliminate them. To some extent, however, old age is a diet-related disease. Aging is a complex and still only incompletely understood process. One of its symptoms is the slow accumulation of an inert substance, lipofuscin, in tissue spaces, notably in the heart. Another symptom of the aging process is the oxidative cross-linking of protein fibres, resulting in loss of elasticity and increasing rigidity of tissues.
