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In an attempt to improve the nutritional value of animal fats (including milkfat and lard), two technological approaches (i.e., cholesterol removal by steam distillation and linoleic acid enrichment by addition of safflower oil) were tested for cholesterolemic effects in a cohort of 29 older women (age 68 +/- 7 years).Test fat sources were incorporated into crackers, cookies, cheese, ice cream, whipped topping, sour cream, baking shortening, and table spreads. Subjects were permanent residents of a convent where meals were prepared in a centralized kitchen, allowing test fats to be provided in daily food menu items. The foods containing test fats were introduced into three sequential dietary treatment periods, each lasting 4 weeks, in the following order: cholesterol-reduced animal fat (CRAF): fatty-acid modified, cholesterol-reduced animal fat (FAMCRAF); and-unaltered animal fat (AF). Subjects were offered menu items cafeteria style and encouraged to make food selections consistent with their habitual diets, which were recorded daily.Fasted blood lipid profiles determined at the end of each treatment period showed that FAMCRAF reduced mean plasma total cholesterol, LDL cholesterol, and apolipoprotein B concentrations relative to AF (p0.05). Mean HDL cholesterol concentrations were not influenced by diet.Relative to native products, animal fats modified by cholesterol removal and linoleic acid enrichment reduced plasma total and LDL cholesterol concentrations in a predictable manner similar to that based on studies of men.

Although there is general agreement that saturated fatty acids elevate plasma cholesterol concentrations, the relative effects of individual fatty acids on cholesterol and bile acid metabolism are less clear. In this study, cholesterol and bile acid responses to diets enriched in different saturated fatty acids were investigated in hamsters. The six diets examined were as follows: 5% fat (g/100 g) enriched in palmitic acid (16:0) with no cholesterol, 5% fat 16:0-enriched, 0.05% cholesterol (wt/wt), and four diets containing 0.05% cholesterol and 15% fat with each diet enriched in lauric (12:0), myristic (14:0), palmitic (16:0), or stearic acid (18:0). Total plasma cholesterol concentration was significantly greater in hamsters fed the 14:0-enriched diet relative to those fed the 18:0-enriched diet (P0.05). Both plasma and liver cholesterol concentrations of hamsters fed 18:0 did not differ from those of the group fed no dietary cholesterol. In all instances, differences in total plasma cholesterol were accounted for within the HDL fraction; no significant treatment differences in VLDL or LDL cholesterol were found. Total daily fecal bile acid excretion was higher in hamsters fed the 15% fat 16:0 diet compared with those fed no dietary cholesterol (P0.05), but not significantly different from other treatment groups. There was greater deoxycholic acid excretion (P0.05) from hamsters fed the 14:0 and 16:0 diets compared with those fed the 18:0-enriched diet. Small intestinal + gallbladder bile acids, an index of pool size, did not differ significantly among the groups. The observed relative hypocholesterolemic effect of stearic acid was not mediated by increased bile acid excretion.

The attribute(s) of soluble dietary fibers responsible for cholesterol lowering is currently uncertain. A series of experiments were conducted in which viscosity and fermentability was assessed independently for their effect on plasma and liver cholesterol concentration. Hamsters were divided into four dietary groups and fed diets containing 0.12% cholesterol and 5% fiber as high viscosity hydroxypropyl methylcellulose (HV-HPMC group), low viscosity hydroxypropyl methylcellulose (LV-HPMC group), high viscosity guar gum (HV-GG group) or low viscosity guar gum (LV-GG group). Hydroxypropyl methylcellulose is essentially nonfermentable, whereas guar gum is highly fermentable. Plasma cholesterol concentrations at 3, 6 and 11 wk and liver cholesterol concentrations at 6 and 11 wk were significantly lower in the HV-HPMC group relative to the LV-HPMC group (P0.05). Intestinal content viscosities of the LV-HPMC and HV-GG groups were similar; consequently, these two groups were compared to examine the independent effect of fermentation. Plasma and liver cholesterol were significantly lower in the HV-GG group compared with the LV-HPMC group at 6 wk (P0.05), but not at 3 or 11 wk. Hepatic sterol synthesis rates were not affected by any of the diets. This study shows that greater viscosity of intestinal contents is strongly associated with cholesterol reduction, but that the contribution of fiber fermentation remains uncertain.

Thirty male weanling Sprague-Dawley rats were fed either a copper deficient diet (0.85 mg Cu/kg) or a copper-adequate diet (8 mg Cu/kg). After 7 weeks, the rats were fasted for 12 hours, and injected intravenously with thyrotropin-releasing hormone (TRH, 30 ng/100 g body weight). Six rats from each treatment were killed at 0, 0.5, 1, 2 and 4 hours after TRH injection. Sera obtained at 0, 0.5 and 1 hour, and at 0.2 and 4 hours were used for the radioimmunoassay of thyroid-stimulating hormone (TSH) and thyroxine (T4), respectively. Reduction in liver copper content confirmed that the rats fed the test diet were copper-deficient. Serum TSH levels appeared to have peaked at 30 minutes but declined to a level higher than basal at 1 hour. No difference in TSH response was observed between the 2 treatments. Serum T4 response to TRH was reduced in the copper-deficient as compared to the adequate rats at all time intervals. After 2 hours a slight elevation was observed in the controls, but marked elevations in T4 were observed in both treatments at 4 hours. This reduction in T4 levels could be due to an impaired T4 synthesis or release in copper-deficient rats.

Phenylpyruvic oligophrenia 1 is a rare, inherited, metabolic fault that appears first in childhood. It involves inability to convert properly the essential amino acid, phenylalanine, into tyrosine and is associated with excretion of phenylpyruvic acid and other abnormal metabolites in the urine. Affected persons are invariably mentally deficient or idiotic 2-6 and are almost uniformly blond, light-skinned, and blue-eyed. 3,5,7 The etiologic relationship to mental deficiency is unexplained 6 ; the relationship to blondness is thought to lie in the inability to convert phenylalanine properly into tyrosine in the process of forming melanin. Certain peculiarities of the skin also have been described in association with phenylketonuria, but this paper is chiefly concerned with the pigmentary aspects of the disorder. In 1934, Folling, 8 of Norway, first described the presence of phenylpyruvic acid in the urine of certain mentally defective patients. A characteristic deep green color appeared