The intake of dietary fat, especially saturated fatty acid, has noticably increased in Japan as a result of the Westernization of eating habits. Itoh et al. have shown that the postprandial insulin release in healthy young women was stimulated by meals rich in saturated fatty acids (SFA). Vanadium is known to be a trace element that mimics the biological effect of insulin. The objective of this present study was to evaluate the effect of mineral water containing vanadium on the insulin insensitivity induced by a diet rich in SFA.
Twenty healthy young women participated in this crossover study. We used two kinds of mineral water containing approximately 60μg/l of vanadium (water A and B). The subjects were assigned to two groups of 10 subjects each forrespectively ingesting water A and water B. Vanadium-free mineral water was used as a control. Each subject ingested each type of water and a diet rich in SFA for 8 days. Fat constituted 30% of the total energy in the ratio of saturated fatty acid (S): monounsaturated fatty acid (M): polyunsaturated fatty acid (P)=5:4:1. On the last day, the plasma glucose level and serum insulin, triglyceride, and free fatty acid levels were measured at 0, 30, 60 and 120min after the evening meal.
Water A reduced the serum insulin level in comparison with the control value 120min after the meal. A similar effect was observed with water B. The postprandial plasma glucose level showed no significant difference between the control and mineral water containing vanadium.
Our results suggested that mineral water containing vanadium had a beneficial effect on the insulin insensitivity induced by a diet rich in SFA.