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Biomedical subjects

L M Smith

Publications and source records attributed to L M Smith.

At least 235 records · Page 13Linked to original sources
PubMed1977

Influence of diet on trans fatty acids in human milk.

In two experiments on relations between diet and milk lipids, subjects recorded food intake for 1 week and saved duplicate portions of foods consumed on 3 days. Diet collections were analyzed for selected nutrients and percent fatty acids. In the first experiment, for 1 week five subjects took morning and evening milk samples for fatty acid analysis. Significant differences were found in percentages of trans- 18:1 and total trans fatty acids between subjects' milks but not between morning and evening samples. In the second experiment six additional subjects collected milk samples in the morning only. Subjects were significantly different in the percentages of trans- 18:1 and total trans acids in their milks. In nine of the 11 subjects the fluctuation of percent total trans acids in the milk appeared to follow dietary trans changes after a 12 to 36 hr lag period. A significant correlation was found for diet and evening milk of the same day. Polyunsaturated/saturated ratios of the fatty acids in the diet lipids were related to those for milk lipids from the same evening and the next morning. Although other factors are involved, diet lipids influence trans fatty acids and polyunsaturated/saturated ratios of the fatty acids in human milk.

Adult↗
PubMed1976

Essential fatty acid deficiency in adults receiving total parenteral nutrition.

In seven adult patients receiving fat-free total parenteral nutrition (TPN) for 4 to 8 weeks, weekly determinations of plasma fatty acids and total plasma tocopherols were made. Four patients were deficient in essential fatty acids, as defined by triene: tetraene ratio greater than 0.4, at the end of the second week of TPN. Six patients were deficient by the end of the third week and all seven were deficient by the end of the fifth week of TPN treatment. One patient who was deficient in both essential fatty acids and zinc developed a scaling, eczemoid dermatitis that disappeared within 3 weeks after cessation of TPN and resumption of oral feedings containing both fat and zinc. After resumption of oral feedings by three patients, the triene: tetraene ratio returned to normal within 2 weeks. The mean of total plasma tocopherols fell over a period of 7 weeks and in three individuals, reached levels generally associated with deficiency. There were not any obvious clinical manifestations of vitamin E deficiency.

Adult↗
PubMed1975

Plasma lipid changes in young adult couples consuming polyunsaturated meats and dairy products.

Twenty-five young couples consumed either a saturated or polyunsaturated fat diet for a 20-week period. The polyunsaturated beef, lamb and dairy products, high in linoleic acid, were produced by feeding ruminant animals "protected lipid" feeds which prevent hydrogenation of fats in the rumen. The experimental design provided for four dietary groups: A) saturated diet for 20 weeks; B) polyunsaturated diet for 20 weeks; C) saturated diet for 10 weeks then polyunsaturated diet for 10 weeks; and D) polyunsaturated for 10 weeks then saturated diet for 10 weeks. Polyunsaturated-to-saturated ratios (linoleic: total saturated fatty acids) for the diets were: prestudy, 0.43-0.56; saturated 0.11-0.14; polyunsaturated, 0.56-0.62. Factors other than diet that appeared to affect cholesterol responses were carefully considered. During the initial 3 weeks (regimentation period) plasma cholesterol concentration decreased in all groups irrespective of diet. This was followed by two experimental periods in which the effects of the prescribed diets were readily apparent (response periods I and II). The final 4 weeks of the study were characterized by diminishing compliance with the dietary discipline (abatement period). Subjects in each group (A,B,C,D) were subdivided into high and low on a basis of each group's initial median cholesterol level. Those in the high subgroups were very responsive to dietary changes whereas those in the low subgroups were not. Combined responses of high subjects were: polyunsaturated diet, -10.7 mg/dl (P less than 0.025), saturated diet, d8 mg/dl (P less than 0.05). Combined difference between saturated and polyunsaturated diets was 18.5 mg/dl or approximately a 10% cholesterol difference between the experimental polyunsaturated and saturated diets.

Adult↗