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Biomedical subjects

M J Gibney

Publications and source records attributed to M J Gibney.

At least 91 records · Page 5Linked to original sources
PubMed1996

Postprandial triacylglycerolaemia: the effect of low-fat dietary treatment with and without fish oil supplementation.

OBJECTIVE: This study investigated whether a low-dose of fish oil had the ability to prevent the adverse effects associated with low-fat dietary treatment, namely elevated plasma triacylglycerol (TAG) and reduced high density lipoprotein (HDL) cholesterol concentrations. DESIGN: Thirty-two healthy volunteers participated in the trial, which consisted of four study groups (n = 8): low-fat diet with fish oil supplementation, low-fat diet without fish oil supplementation, full-fat diet with fish oil supplementation and full-fat diet without fish oil supplementation. Low-fat dietary treatment reduced dietary energy derived from fat by at least 10% and the low-dose of fish oil provided 1 g n-3 polyunsaturated fatty acids (PUFA) daily. The postprandial response to a fat-rich test meal (0.5 g/kg pre-trial body weight) was investigated before and after 16 weeks dietary intervention. RESULTS: Fasting plasma TAG concentrations were significantly (P < or = 0.05) reduced by fish oil supplementation and significantly (P < or = 0.05) increased by the low-fat diet alone but not significantly affected following the low-fat diet with fish oil supplementation. The postprandial TAG response was significantly (P < or = 0.05) increased following the low-fat diet with fish oil supplementation. CONCLUSION: This study demonstrated that some of the deleterious effects of a low-fat diet, reduced concentrations of the cardioprotective HDL2 cholesterol fraction and increased fasting plasma TAG concentrations were prevented when a low dose of fish oil was provided with a low-fat diet. However postprandial triacylglycerolaemia is adversely affected when the low-fat diet was supplemented with fish oil.

Adult↗
PubMed1996

Women's dietary fat and sugar intakes: implications for food based guidelines.

OBJECTIVE: To examine how women's dietary data can be used to formulate food based dietary guidelines for fat. DESIGN: Dietary intake data was assessed cross-sectionally using the 7 d diet history method. Subjects were divided into quartiles on the basis of their intakes of total fat and saturated fatty acids (% energy) and the diets of those in the lowest and highest quartiles were compared. SUBJECTS AND SETTING: Subjects studied were socially advantaged and disadvantaged women (n = 83, mean age 35 years) recruited from their workplaces. RESULTS: The inverse relationship between intakes of sugar and total fat (P < 0.0001) found in this study also extended to saturated fatty acids (P = 0.0007). Women in the lowest quartile of total fat, in common with those in the lowest quartile of saturated fatty acids, were found to have higher intakes of fibre (P < 0.005), vitamin C (P < 0.01), folate (P < 0.005) and vitamin B6 (P < 0.05) while their intakes of vitamin A were lower (P = 0.01). Most (76%) of the differences in sugars intake between women of low and high total fat consumption were accounted for by added sugars, particularly non-fat containing confectionery/drink food sources where median daily intake values were 15 g vs 7 g sugars (P = 0.05) respectively. The finding that at best only 62% of the women had total fat and saturated fatty acids intake in similar quartiles, together with the differences that emerged in their food intake patterns, indicate that the goals for these nutrients may be separately achieved. CONCLUSION: Existing dietary data can be useful for the formulation of specific food based dietary guidelines and diets higher in sugar are not necessarily more dilute in micronutrients.

Adult↗
PubMed1994

The effect of consumption of fish oil-enriched spreadable fats on platelet phospholipid fatty acid composition in human volunteers.

Thirty-three male subjects were randomly allocated to one of three treatments which involved the consumption of 50 g/d of either one of three spreadable fats for twelve weeks. Group A consumed their normal spreadable fat; group B consumed a low-fat spread (40% fat wt/wt) which contained 8 g of fish oil per 100 g of product; group C consumed a high-fat spread (80% fat wt/wt) which contained 8 g of fish oil per 100 of product. Baseline levels of platelet phospholipid eicosapentaenoic acid (C20:5 n-3) were < 1.0% wt/wt at baseline in all groups and increased significantly (p < 0.05) in both groups receiving fish-oil containing spreads (12 week values of 1.5 +/- 0.5 for group B and 2.4 +/- 1.3 for group C). There was no change in the control group receiving their normal spreads. The ratio of all n-6; n-3 polyunsaturated fatty acids fell significantly in group B (12.5 +/- 3.1 v 1.7 +/- 1.9) and in group C (8.2 +/- 3.9 v 6.7 +/- 2.6), both of whom received fish oil. These two groups also achieved a significant (p < 0.05) increase in platelet phospholipid docosahexaenoic acid (C22: 6 n-3): 2.3 +/- 0.5 v 2.9 +/- 0.9 in group B and 2.3 +/- 0.6 v 3.1 +/- 0.9 in group C. The subjects encountered no important palatability or acceptability difficulties. These data show that, in individuals with low intakes of fatty fish, spreadable fats enriched with fish oil are a useful vehicle for ensuring adequate intakes of n-3 polyunsaturated fatty acids.

Blood Platelets↗
PubMed1994

The incorporation of n-3 polyunsaturated fatty acids into plasma lipid and lipoprotein fractions in the postprandial phase in healthy volunteers.

OBJECTIVE: To examine the movement of long-chain polyunsaturated n-3 fatty acids across plasma lipoprotein fractions in the postprandial phase. DESIGN: Eight healthy volunteers ingested a test meal (% energy: protein 11, carbohydrate 16, fat 73) after an overnight fast where fish oil provided the sole fat source. Blood samples were taken at baseline and at hourly intervals thereafter for 12 h. Blood lipoprotein fractions were separated and analysed for triacylglycerol fatty acid compositions. These were also determined in non-esterified fatty acid and phospholipid fractions. RESULTS: All n-3 polyunsaturated fatty acids accumulated in all plasma lipoprotein fractions and in non-esterified fatty acids. The ratios of concentrations of docosahexaenoic acid (DHA) to eicosahexaenoic acid (EHA) were higher in chylomicrons (1.4 +/- 0.4) than in very low density lipoproteins (0.9 +/- 0.5) and particularly higher than in the non-esterified fatty acid fractions (0.8 +/- 0.4). The level of eicosapentaenoic acid (EPA) rose significantly in plasma phospholipids while that of docosahexaenoic acid (DHA) did not. CONCLUSIONS: All n-3 polyunsaturated fatty acids are rapidly incorporated into all plasma lipid fractions with the exception of uptake of DHA into plasma phospholipids. There is a clear tendency for EPA and DHA to partition differently into the different plasma lipid fractions.

Adult↗
PubMed1994

The effects of altered frequency of eating on plasma lipids in free-living healthy males on normal self-selected diets.

OBJECTIVE: To examine the effects of modifying meal consumption frequency on blood lipids in free-living healthy male volunteers on self-selected diets. DESIGN: Cross-over study of snacking to non-snacking and non-snacking to snacking patterns. SETTING: Civic Offices, Dublin. SUBJECTS: 12 men with a mean (SD) eating frequency of 6.0 +/- 0.8 times per day ('snacking') and 11 men with a frequency of 3.1 +/- 0.1 meals per day ('non-snackers'). INTERVENTION: The 'snackers' moved from 6.0 to 3.3 +/- 0.3 meal-eating occasions per day while the 'non-snackers' moved from 3.1 to 5.9 +/- 0.9 times per day. It was intended that these modifications of eating frequency would not be the cause of modified nutrient intake in the cross-over period. MAIN OUTCOME MEASURES: Nutrient intake, plasma total, high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol, plasma triglyceride and apoproteins A-I and B. RESULTS: There was a significant treatment (cross-over) effect on plasma total cholesterol (P = 0.038), LDL cholesterol (P = 0.038), HDL/LDL cholesterol ratio (P = 0.013) and apo A-I/B (P = 0.029). There were no significant nutrient changes on moving from meal-eating to snacking but on moving from snacking to meal-eating there were significant changes (P < 0.005) in the % energy from protein, fat, saturated fatty acids and alcohol. These changes accounted for all the changes in blood cholesterol in this group. When the data for meal-eating to snacking were analysed separately, given that nutrient intakes did not change, a significant effect of altered meal-eating frequency was found for total cholesterol (P = 0.027) and HDL/LDL (P = 0.015). CONCLUSION: These data on free-living subjects following normal self-selected diets support the hypothesis and the substantial related literature that more frequent meal consumption has a favourable effect on lowering plasma cholesterol and raising the HDL/LDL cholesterol ratio.

Adult↗
PubMed1994

Food and nutrient intakes and eating patterns in functional and organic dyspepsia.

Forty organic dyspepsia patients and 40 functional dyspepsia patients, endoscopically diagnosed, were recruited from a gastroenterology outpatient unit and were age- and sex-matched with an equal number of patient controls. A diet history of typical eating patterns for a 7-day period was taken and food portions quantified using a photographic atlas. An interviewer-assisted questionnaire was used to identify present eating habits, dietary patterns reported to exacerbate or relieve symptoms and alterations in eating habits as a result of symptoms. Females with organic or functional dyspepsia reported significantly lower energy intakes (P < 0.01) than controls. Females with organic dyspepsia had significantly lower intakes of fat, carbohydrate, fibre and a wide range of micronutrients compared to controls. Females with functional dyspepsia had significantly lower intakes of fat, sugars and vitamin C (P < 0.05) than controls. Organic dyspepsia patients (male and female) had significantly lower intakes of alcohol and vitamin C than controls (P < 0.05). Patients with organic dyspepsia had higher intakes of milk and lower intakes of fresh fruit and/or fruit juice than controls. The main difference in eating pattern noted was that a significantly lower percentage (P < 0.05) of functional dyspepsia patients than controls regularly ate three meals per day. Large numbers of dyspepsia patients in both groups associated certain eating habits and the consumption of specific foods with exacerbation of dyspeptic symptoms and over 80% of both groups reported food avoidance as a result of this.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Indices of obesity and body fat distribution in arteriographically defined coronary artery disease in men.

Anthropometric measurements descriptive of obesity, body fat distribution and body build were made in 186 males undergoing diagnostic coronary arteriography. Using stepwise multiple logistic regression analysis, two indices of body fat distribution were independently associated with coronary disease, while the widely used indices of obesity, namely body mass index and percentage body fat, were not. A significant association with disease was found for the ratio of waist to thigh circumferences (waist/thigh ratio), which emerged in the first step of the multivariate model (p < 0.005). The ratio of waist to hip circumferences (waist/hip ratio), a widely used index of body fat distribution, was found to have a negative association with disease (p < 0.05). This study suggests that use of body fat distribution indices may assist in the assessment of the risk factor profile of cardiac patients.

Adipose Tissue↗
PubMed1993

Inter- and intra-fat pad variation in vascularization and the release of 14C-labelled fatty acids in mice.

Adult laca mice were dosed orally with 150 microliters whole milk containing 2.5 microCi of either labelled stearic acid ([1-14C]18:0; n 20) or labelled linoleic acid ([1-14C]18:2; n 20). The mice were killed in groups of four at 6, 12, 24, 48 and 96 h following dosing and samples of perirenal and epididymal fat pads were taken from both inner and outer sites at each location. Significant differences in the rate of loss of label between sites were found. No differences (P = 0.018) between fat pad locations (epididymal v. perirenal) were found. A significant interaction between rate of loss of labelled fatty acid and site (P = 0.019) reflected the fact that between-site variations in this context were confined to labelled linoleic acid. In a second study weanling adult (n 10) and adult (n 10) mice were killed and their epididymal and perirenal fat pads prepared for histological examination. Both transverse and longitudinal sections were taken at the inner and outer sites of each fat pad location. Following staining, both the size and number of blood vessels were measured using computer-linked microscopy. In all instances there were significant differences between sites with the inner site consistently showing greater numbers and areas of blood vessels. In general the number of blood vessels in the inner site tended to be greater in older mice, while the reverse was seen for younger mice. The results lend support to the concept of multiple pools of triacylglycerol-fatty acids in adipose tissue such that the main determinant of short-term supply of essential fatty acids is the quantity recently ingested.

Adipose Tissue↗
PubMed1993

Calcium intakes in individuals on diets for the management of cows' milk allergy: a case control study.

Three hundred and twenty-three individuals with self-reported food allergy were recruited by media advertisements. Questionnaire information was collected on all respondents. Chocolate (57%), milk (47%), wheat (36%) and food additives (35%) were the most frequently implicated foods. The most frequently reported symptoms were itching (43%), skin rash (43%) and tiredness (43%). Food avoidance was the most common form of food allergy diagnosis (33%) with only 8% of respondents reporting food challenge in food allergy diagnosis. Self-diagnosis was reported by 34% of respondents with 29% and 24% reporting diagnosis by a general practitioner or a homeopath, respectively. Twenty-four per cent of respondents 'always' avoided and a further 57% 'nearly always' avoided the implicated food(s). A group of 38 adults with self-reported 'milk allergy' was selected for further study. Dietary assessments, using the dietary history method, were carried out on this subgroup and on age-, sex- and occupation-matched controls. The results of the dietary assessments revealed that the 'milk allergy' group had significantly higher intakes of fibre, beta-carotene, vitamin C, vitamin E, iron and folic acid (P < 0.05) and significantly lower intakes of calcium (P < 0.002) in comparison to controls. Eighteen per cent of the group used milk alternatives. Thirty-four per cent of the 'milk allergy' group took calcium-containing supplements. Even after calcium supplementation, the mean calcium intake of those who completely avoided milk was unacceptably low (441 mg/d).

Adult↗
PubMed1993

The effects of short- and long-term supplementation with fish oil on the incorporation of n-3 polyunsaturated fatty acids into cells of the immune system in healthy volunteers.

Eight healthy male volunteers supplemented their normal diet with 10-15 g/d of a fish oil supplement (MaxEPA) to provide 1.4-4.2 g/d of eicosapentaenoic acid (EPA; C20:5 n-3) for a period of 12 weeks. Blood samples were taken at weeks 0, 2 and 12 and the fatty acid compositions of the phospholipids of plasma, platelets, neutrophils, monocytes and T- and B-lymphocytes were determined. In all instances the level of EPA increased significantly (P < 0.05) by 2 weeks and remained so without a further increase for the ensuing 10 weeks. Beyond that, few consistent patterns in fatty acid composition were observed. Arachidonic acid (C20:4 n-6) fell significantly (P < 0.05) in plasma, platelets, neutrophils and T- and B-lymphocytes, but generally tended to do so only by week 12. Given the wide variability in the half-life of these cells (minutes for neutrophils, months for lymphocytes) it is evident that uptake of plasma EPA occurs by phospholipid exchange into preformed mature cells and does not require incorporation during cell genesis.

Adult↗
PubMed1992

The effects of acute and chronic administration of n-6 and n-3 polyunsaturated fatty acids on ethanol-induced gastric haemorrhage in rats.

Female weanling rats in three equal groups (n 12) were given orally by intubation 1 ml micellar solution of taurocholic acid (10 mM) and either arachidonic acid (20:4 n-6), linoleic acid (18:2 n-6) or eicosapentaenoic acid (20:5 n-3) at a concentration of 120 mM. After 1 h the rats were given intragastrically 2 ml absolute ethanol and were killed 1 h later. Rats given oral 20:4 n-6 showed a significant reduction (P less than 0.05) in the extent (%) of gastric mucosal haemorrhage compared with either the rats given 20:5 n-3 or 18:2 n-6 (8.3 (SD 7.3), 23.2 (SD 10.4) and 21.4 (SD 10.4) respectively. In a second experiment, four equal groups (n 12) of female Wistar rats were fed for 5 weeks on either a control diet of standard laboratory rat food, or the same diet enriched with either maize oil or fish oil or butterfat at a level of 100 g/kg. Following a 24 h fast the rats received an intragastric dose of 2 ml ethanol and were killed 1 h later. Examination of the extent (%) of gastric lesion showed a significant reduction (P less than 0.05) with the feeding of either maize oil or fish oil compared with the controls (12.2 (SD 8.2), 15.3 (SD 13.2) and 29.3 (SD 14.0) respectively). The butterfat diet was not significantly different from the control diet (23.8 (SD 8.1)).

Animals↗