OLD AGE. - Biologists and physicians today tend to differentiate the concept of senescence from that of senility or V. Thus, according to Pende, the first term should denote the process of functional decline and structural deformation of the organism that naturally affects all parts at varying times and degrees at a certain stage of life; whereas senility or V. refers to the vital phase in which the phenomena of senescence have already become evident and definitive.
According to biologists, senescence (v.) is a characteristic and essential property of life (v. BIOLOGICAL CYCLES). However, it applies to all complex organisms. Alongside growth and death (v.), it is one of the most distinctly specific properties of organized living matter, as essential as metabolism, to which it is closely linked. The increasingly deeper understanding of the life of unicellular elements, the knowledge of the transmission of life through the fertilized ovum, CARROLL (v.), who succeeded in keeping a fragment of embryonic myocardium alive for 28 years by cultivating it under special environmental conditions, have increasingly supported the hypothesis that the phenomenon of senescence and death should not be regarded as specific to living matter but rather as a particular attribute of the organizational process by which the higher individual is constituted.
Senility was once considered a directly pathological phenomenon (senectus ipsa morbus); today, however, it is regarded as a physiological event proper to living organisms, inasmuch as, although it may be aggravated and hastened by the aftereffects of previous diseases and countless other physical and psychological factors of decline that accompany human existence, it begins at a given stage of life (60-70 years for man, 55-65 for woman) independently of any concomitant morbid factor, with a set of involutionary and degenerative phenomena that affect the entire organism, profoundly altering it from morphological, biochemical, and physiological standpoints. Pende maintains that senility is characterized by multiple deficit phenomena: circulatory stasis; toxic stasis in the interstitial lacunar system of the organs; gastrointestinal stasis with autointoxication of the organism from smoke, products of incomplete digestion of albumins, and toxins from the intestinal bacterial flora; altered neurovegetative (v. NEUROVEGETATIVE SYSTEM) and metabolic (v. METABOLISM) balance with a tendency toward sympathetic hyperfunction, acidosis, accumulation in the blood of cholesterol, glucose, nitrogen, uric acid, and a decrease in calcium; impaired function of the endocrine glands (v.), liver, and kidneys; and others.
These phenomena are due to or accompanied by alterations in certain tissues, systems, and apparatuses that are affected by the involutionary process of senescence earlier than others. Thus, the atrophy of elastic tissue, whether in the skin (facial wrinkles), blood vessels (arteriosclerosis), lungs (senile emphysema), or intestinal and abdominal walls (protrusion of the abdomen); the hypofunction of the reticuloendothelial system, which regulates thrombosis, vitality, and the body’s defensive powers against external agents, is responsible for the senescence of the more specifically differentiated tissues of the organs; the entire endocrine gland apparatus is disrupted in its hormonal correlation, with phenomena of hypofunction (insular gland, thymus, gonads) or hyperfunction (especially the adrenal cortex, the basophilic portion of the pituitary, and the thyroid) or variable alternations (hyper- or hypoparathyroidism).
According to Viale, the physiological and biochemical phenomena that characterize senility are mainly: the quantitative decrease in functions and the reduced capacity to adapt to environmental changes.
Various hypotheses have been proposed to explain the onset of V. Some consider a toxemia of intestinal (Metchnikoff) or extraintestinal (Jeckel-Ewald) origin as the basis of the senescence process; others, an endocrine disorder of the pituitary, adrenal, or complex nature (Simmonds, Lorand, Gley); others, a more or less complex metabolic disturbance (Bornstein, Pende); others, the physicochemical differentiation of tissues due to dehydration and precipitation of protoplasmic colloids; and still others, such as Carrel’s suggestive theory, consider the direct cause of senility to be an alteration of the humoral environment of cells, which would be deprived of the ‘something’ necessary for normal growth (Carrel’s ‘trefoni’).
Regarding the possibility of prolonging life and making senility less burdensome, Legrand states that ‘il n'y a pour vivre vieux, ni règle, ni méthode, ni hygiène spéciale’. However, in 1796 Hufeland published his Macrobiotics or the Art of Prolonging Life, and Lorand, in his book Rin-giovaniere (Turin 1926), listed bad habits as causes of premature senility and death (alcohol, excessive nutrition, tobacco, sexual excess, filth, ambition, avarice, anger, vanity, practices aimed at avoiding offspring). The importance of these and other factors, such as idleness, insomnia, and constipation, is undeniable; yet in the establishment of V. at an earlier or later stage of life, extra-individual factors such as heredity, race, climate, and temperature also play a role, so that it can be affirmed that each individual ages in his own way, with one or another particular organ being more predisposed to senile involution at a given stage of life.
According to Marinesco, ‘v., like death, are fatally inscribed in the vital curve of colloids and implicitly in the evolution of cells. Life and death are natural and necessary phenomena, and the hypotheses of authors who see in the phenomena of senescence an accident that can be remedied are at odds with the universal law governing the life of colloids (festschrift in honor of L. Bianchi, Catania 1913).’ Many authors in various countries, however, have tackled the problem of the possibility of rejuvenation, sometimes proposing solutions that are suggestive, even if, at least for now, only temporary.
The first to arouse interest in the problem of rejuvenation—understood as a return of the old and infirm to the bodily and spiritual conditions of youth—was Brown-Séquard, who thought of injecting subcutaneously into the elderly and sick the juice extracted from the testicles of animals, having first successfully tested it on himself at the age of 72. Since then, numerous other researchers have addressed the same problem in various ways: Steinach and Lichtenstern through vasoligation, Döppler through periarterial sympathectomy, Zucchi with a diathermic procedure, and down to our own day, which has seen staunch defenders and vehement opponents of the method proposed by Voronoff and developed by Dargues, based on the transplantation of monkey testicles into humans. It is also worth recalling two other recent methods: that of Jaworski, based on the intravenous introduction of young blood, and that of Cavazzi, who advocates the injection of testicular venous blood taken from young and healthy animals.
At the present time, however, no proposed method has yielded consistent and definitive results. According to Marinesco, even if there is an undoubted relationship between life and the sexual glands, it cannot be said that old age depends on the state of these glands. For the author, the decline of the gonads is not the cause but rather one of the signs of old age.
Kotsawski is also convinced of the impossibility of achieving rejuvenation through opotherapy and hormonal treatments, arguing (Riv. Biol., 12 [1930], p. 40) that to rejuvenate the organism there is no other way than to replace damaged and diseased organs with healthier ones.
According to Pende, prolonging human life—active and free from infirmities, that is, adding life to years rather than years to life—by at least a quarter of a century is scientifically possible, but it is a problem of constitutional, individual, biopolitical medicine that requires hygiene and a complex, multifaceted medicinal and opotherapeutic therapy. In relation to the increased average lifespan (65–67 years) and the growing percentage of elderly in the population, medicine is currently showing increasing interest in the problem of V. and its treatment, giving rise to the growing development of two new branches: “gerontology” and “gerontiatrics.”