J R Mahalko

Increased cholesterol in plasma in a young man during experimental copper depletion

Signs of copper depletion were produced in a healthy man by an amount of dietary copper (0.83 mg/day) similar to that in some contemporary diets. Urinary and fecal loss of copper exceeded intake. Plasma copper, ceruloplasmin, and superoxide dismutase activity in erythrocytes decreased. Cholesterol in plasma increased, and hematologic indices were unchanged. Lipid metabolism may be a more sensitive index of copper nutriture than are changes in hematology. The findings support the hypothesis that inadequate copper nutriture or altered copper metabolism contributes to the occurrence of ischemic heart disease.

Dietary Fiber and Personality Factors as Determinants of Stool Output

We examined effects of fiber on stool output, since this is one of the primary mediating variables for the hypothesized relationship between fiber and disease. Total neutral detergent fiber in the dietary fiber source was predictive of stool weight but not frequency. Substantial individual differences in stool output remained when dietary factors were controlled. Personality measures were used to predict stool weight and frequency independently of diet, and accounted for about as much variance in stool output as did dietary fiber. These results suggest that personality factors predispose some persons to low stool output. These individuals may benefit particularly from dietary fiber.

Effects of Modest Amounts of Wheat Bran and Dietary Protein on Mineral Metabolism of Humans

Adverse effects of whole meal wheat bread on retention of calcium and iron by men were reported by McCance and Widdowson in the early 1940’s.1,2 Since then, their findings have been confirmed by others. One of these later investigators was Reinhold who showed that common whole meal wheat bread of Iranian villagers and Mexican tortilla impaired retention of various essential minerals. 3–6 His findings provided substantial support for the hypothesis that habitual consumption of large amounts of such breads is an important factor in the occurrence of zinc deficiency among the poor of Third World countries. Because the poor of Third World countries subsist in large part on cereals, the relevance of these findings for persons who consume western type diets which include only modest amounts of whole-grain cereal products is unclear.