The effect of coffee-drinking on blood composition was studied in 20 healthy volunteers who normally consumed, on average, 560 mg caffeine/day from tea and coffee. After 14 days on decaffeinated coffee (12 mg caffeine/day) there was a reduction in blood glucose, a small rise in plasma cholesterol and phospholipid, and a more substantial fall in triglycerides. The substitution of coffee for decaffeinated coffee (875 mg caffeine/day) for 20 days did not affect blood glucose, but the changes in the plasma lipids were reversed. There was no change in the level of immunoreactive insulin, in platelet adhesiveness, fibrinogen or blood clot lysis time during the course of the experiment. The part played by caffeine and by coffee solids other than caffeine in the induction of these changes does not support the hypothesis that the consumption of coffee is a significant factor in the development of coronary heart disease.

Summary A study was made of the effect of high or low intake of sucrose for periods of 14 days in a group of nineteen apparently healthy men. The high sucrose diet produced no change in blood levels of cholesterol or phospholipids, or in glucose tolerance, but it produced a significant rise in triglycerides in all nineteen men. In six of them, there was in addition a rise in serum immunoreactive insulin, especially during the glucose tolerance test, and these same six subjects also showed a considerable increase in weight and a significant increase in platelet adhesiveness. There was no difference between the six subjects and the remaining thirteen in any of the other measurements, or in the diets they consumed during the experiment. The changes produced by sucrose had disappeared, or nearly so, after 14 days of normal diet. It is suggested that the effect of sucrose in producing hyperinsulinism may be more relevant to its possible role in the aetiology of ischaemic heart disease than its effect on blood lipids. It is further suggested that only some individuals are susceptible to the development of ischaemic heart disease by dietary sucrose, and that these may be identified as those that show ‘sucrose-induced hyperinsulinism’.

Summary Both the level of serum insulin and the adhesiveness of platelets are correlated with sucrose intake in men with peripheral vascular disease. These correlations do not exist in men who have no signs or symptoms of the disease, or of predisposing conditions such as hypertension. The results support the suggestion of Szanto & Yudkin (1969) that an habitual high intake of sugar raises the insulin level in some individuals but not all, and that these individuals are susceptible to the effect of sucrose in producing occlusive arterial disease.

Plasma Insulin and II-Hydrocorticoid after Sucrose 417 that analogous repetitive cyclic pulsing for maintaining activity of bare platinum oxygen electrodes was studied by O/sen, Brackett and Crickard (1949) who applied a polarizing voltage periodically in the sequence: negative pulse-short circuit-positive pulse-short circuit. Good results for O 2 measurements were obtained with this technique in blood by Mochizuki and Barteis (1955) and Bürger, Lübbers and Ockenga (1957). The development of a combination sugar oxidation catalyst-conductive screen should make it possible to adapt an analogous tech-References Brown. H.D .. CA. Brown: New. highly active metal catalysts for the hydrolysis of borohydride. J. Amer. chem. Soc.84: 1493-1494 (1962) Brown, H. C, CA. Brown: A simple preparation of highly active platinum metal catalysts for catalytic hydrogenation.