Commercial soybean starch blocker consumption: impact on weight gain and on copper, lead and zinc status of rats.

A commercial 'starch blocker' was used to study the digestion of starch (potato) in mature female rates for four weeks. Two levels of 'starch blocker' were used. The first level was calculated to inhibit starch digestion at 50%, the second was calculated to inhibit starch digestion at 100%. No significant effects on the body weights (271.10 +/- 29, 277.7 +/- 43, 259.1 +/- 25 g) were found among the groups of rats at 0%, 50% and 100% inhibition levels, respectively. Feed intakes were not affected. However, fecal copper and zinc excretions increased significantly (p less than 0.05) due to the inhibitors. Fecal copper excretions were 0.468 +/- 0.14, 0.578 +/- 0.09, 0.617 +/- 0.07 mg/rat/week, while fecal zinc values were 0.625 +/- 0.14, 0.859 +/- 0.32 and 0.778 +/- 0.26 mg/rat/week when no inhibitor was fed, at 50% inhibition and at 100% inhibition respectively. Thus, while use of 'starch blockers' did not promote weight loss in the mature female rats, utilization of copper and zinc were negatively affected.

Inhibitors of copper bioutilization: fiber, lead, phytate and tannins.

Considerable evidence suggests that copper intakes of Americans have declined in recent years to levels that might be considered seriously low. Under such conditions, other dietary factors which inhibit copper utilization might be of concern since otherwise marginally adequate copper diets might be made copper deficient. A large number of mineral nutrients have been found to interact with copper. Non-nutrient substances in food also may affect copper utilization. Evidence suggesting that lead, certain kinds of dietary fiber, phytates and tannins inhibit copper utilization are reviewed in this paper.

Serum total cholesterol and HDL-cholesterol levels as associated with copper and zinc intake in physically active and sedentary elderly men and women.

The relationship of copper and zinc intake with serum total cholesterol, and HDL-cholesterol was studied in physically active and sedentary elderly men and women (N = 63). Three-day diet records over a period of twelve months and fasting blood samples were collected from each subject. Physical activity was associated with higher copper and zinc intakes, lower serum total cholesterol and higher serum copper levels. Higher copper intakes were associated with lower serum total cholesterol. Higher zinc intakes were associated with lower HDL-cholesterol levels. Higher copper serum levels were associated with lower serum total cholesterol. These results appeared inconsistent with the reports from animal studies. However, with it should be noted that the subjects in this study had copper and zinc intakes below the recommended dietary allowances and the calculated zinc to copper ratios were within the desired ranges.