Our previous studies show that a formulation composed of inhibitors of the gastrointestinal absorption of starch and sucrose were effective at lessening their absorption in rats and pigs 26
. To determine whether the CHO blocking effects persisted, rats were followed for nine weeks with daily gavages of a formula containing so called starch and sucrose blockers. Over this time period, we found no significant changes in the rate of body weight gain compared to control, although there was a tendency to see a lower gain in the group receiving the formula. Continuation of this study might have resulted in a significant difference. When the drinking water was changed to 10% w/v sucrose in week 5, the systolic blood pressure (SBP) of the control rats began to rise, whereas the SBP of the test rats showed no such elevation. In our experience, changes in the SBP are a very sensitive marker of insulin sensitivity, i.e., a rise in SBP correlates with the development of insulin resistance 27
. The prevention of the blood pressure elevation suggests that the CHO blockers overcame the induction of insulin resistance brought on by refined CHO.
In the seventh through ninth week, the rats exposed daily to a combination of carb blockers received acute challenges of starch, sucrose and glucose in the same manner as the first acute studies 26
. After weeks of receiving the formula containing carb blockers, it was still able to lessen CHO absorption similar to that seen in the acute studies 26
. The utility of combining natural products containing inhibitors of both starch and sucrose absorption was strengthened when a combined starch-sucrose challenge, simulating a meal containing both, was influenced favorably by the novel formulation (Fig. ).
In the previous acute study 26
, we had not seen any effects on circulating glucose levels in rats receiving only CHO blockers with no CHO challenge. These results suggested that the CHO inhibitors were not working on overall CHO metabolism. Findings in the present study corroborate that opinion. Unlike the challenges with rice starch and sucrose, glucose challenge was not affected by the formulation of natural products, suggesting little direct effect on exogenous glucose absorption or endogenous metabolism (Fig. ) 28
. The latter finding in vivo
again supports an effect of the natural products on the enzymes amylase and sucrase rather than on glucose absorption or metabolism 29-37
After nine weeks of daily intake of carb blockers, there was a significant lowering of circulating glucose levels in the test compared to the control rats. This finding is consistent with the trend to have lower circulating HbA1C levels in rats consuming carb blocking formulation. Perhaps only a trend was seen In HbA1C levels, because the time of imbibing the sucrose solution was not long enough to produce large differences in the latter measurement.
The decrease in serum sodium and chloride concentrations coinciding with the increase in potassium levels suggests an effect of the formula on the renin-angiotensin-aldosterone system 38
. Because angiotensin 2 can influence water intake 39
, a decrease in circulating angiotensin 2 might explain, at least in part, both the lower water intake and the decrease in SBP. Dietary CHO have long been known to influence hormonal systems such as the renin-angiotensin-aldosterone and catecholamine systems 40,41
These results support the hypothesis that CHO blockers like those examined in the present investigation will theoretically lower glycemic indices of various foods. Their activity continues even after weeks of constant intake. Further studies are needed to determine these ingredients will have a significant role in the therapy of various facets of the metabolic syndrome -- including the aging process.