Moderation in food is necessary above all things, for much food causes an increase in the abdominal circulation and a larger amount of blood to be carried through the vessels; if the food consists of much meat, then its viscosity is augmented, as previously stated, which indicates that a vegetable diet, with milk, and little or no meat, is the best; but too large quantities of milk should not be taken at one time. Much bodily and other exercises, in excess, such as too much climbing, should be avoided, as they promote arteriosclerosis by frequent excitation of the splanchnics and adrenals. As Romberg observed, there is sclerosis of the arteries in the extremities of persons who do much physical labor, and Remlinger[209] found the same in the lower extremities of peasant women who walked a great deal. Footnote 209: Remlinger: “Dissertation on Arteriosclérose,” Marburg, 1905. Not only by a diet, chiefly vegetarian, is the viscosity of the blood diminished and the circulation facilitated as found by Determann, but also by means of iodine administered in the shape of iodide of potassium or iodide of sodium. This has been proved by the experiments of Ottfried, Müller, and Inada.[210] For many years it has been well known that iodine can greatly benefit the condition of arteriosclerotic persons. In combination with a preparation of iodine, Professor Senator[211] favors the use of nitrites, and Professor Huchard also recommends nitroglycerine in the intervals between the iodide treatment. Besides inorganic iodine, it would appear to us logical to try organic iodine preparations, such as thyroid extracts, the principal element of which is iodine. For the above reasons it is also necessary to take special care of the condition of the kidneys, which can be done, as we have shown, by hygienic and dietetic measures, already described in the special chapters of this work. An improvement in the condition of the kidneys, and probably also in the arteriosclerosis, may, in our judgment, be obtained by the administration of kidney extracts, with which we will deal more fully in the chapter on the treatment of old age by organic extracts. Footnote 210: Preface of Romberg: Deutsche Med. Wochenschrift, No. 78, 1904. Footnote 211: “Therapie der Gegenwart,” March, 1907. According to Edgreen, about 25 per cent. of the cases of arteriosclerosis is caused by alcohol. It acts by causing a constriction of the small vessels (Traube), just as does adrenalin.