Biomedical subjects

Catherine E Roynette

Publications and source records attributed to Catherine E Roynette.

6 recordsLinked to original sources

PubMed2006

Age- and dose-dependent effects of an eicosapentaenoic acid-rich oil on cardiovascular risk factors in healthy male subjects.

Supplementation with fish oils, rich in n-3 polyunsaturated fatty acids, modifies cardiovascular risk factors. However, dose-response relationships are poorly defined and whether similar effects are seen in young and older subjects is not known. This study determined the effect of supplementing the diet of young and older male subjects with different amounts of an eicosapentaenoic acid (EPA)-rich oil. Healthy young (18-42 years) and older (53-70 years) males were randomized to placebo or 1.35, 2.7 or 4.05 g EPA/day for 12 weeks. There was no effect of EPA on blood pressure or on plasma total, LDL or HDL cholesterol. EPA lowered plasma triacylglycerols, with the maximal effect at the lowest dose. Plasma lipoperoxides decreased in all groups. EPA decreased the lag time of copper-induced lipoprotein peroxidation and the ratio of reduced to total glutathione in the older subjects. The highest dose of EPA increased soluble E-selectin in young subjects, while increasing EPA tended to decrease soluble intercellular adhesion molecule 1 in young and older subjects. Young and older males will gain cardiovascular benefit from increased intake of EPA. Young males are unlikely to suffer adverse consequences from high EPA intake, whereas older males may have an increased risk of lipoprotein peroxidation.

Adolescent↗

PubMed2006

Phytosterols mixed with medium-chain triglycerides and high-oleic canola oil decrease plasma lipids in overweight men.

Phytosterols (PSs) have been recently added to various mediums. Nevertheless, matrices with functional properties, such as medium-chain triglycerides (MCTs), should be precisely examined for supplementary advantages. The objective of this study was to identify the existence of combined biological actions of a functional oil enriched in PSs within MCTs and high-oleic canola (HOC), relative to a control (olive oil), in overweight, hyperlipidemic men using a rigorously controlled dietary intervention. Twenty-three overweight, hyperlipidemic men consumed both types of oil in a randomized, crossover trial for 6 weeks each. Fasted plasma samples were collected on the first and last 2 days of each study period. Body weight decreased -1.22 +/- 0.35 kg (P = .0019) and -1.68 +/- 0.47 kg (P = .0016) after the 6-week study period in the olive oil and functional oil groups, respectively. The end points for total cholesterol and low-density lipoprotein cholesterol (LDL-C) in the functional oil group (P = .0006) were lower than in the olive oil group (P = .0002). Total cholesterol values decreased from comparable baseline to end point of 4.71 +/- 0.16 mmol/L (P < .0001) in the functional oil phase and 5.14 +/- 0.19 mmol/L (P = .0001) in the olive oil phase (P = .0592). In addition, LDL-C demonstrated a similar drop, to an end point of 3.12 +/- 0.16 mmol/L (P < .0001) and 3.54 +/- 0.18 mmol/L (P = .0002), for the functional oil and olive oil groups, respectively, with significant changes (P = .0221). High-density lipoprotein cholesterol levels did not change in either treatment. Triacylglycerol end points decreased in functional oil and olive oil groups (P = .0195 and .0105, respectively) to the same extent from baseline. Results indicate that PSs mixed within an MCT- and HOC-rich matrix lower plasma LDL-C, without significantly changing the high-density lipoprotein cholesterol concentrations, in hyperlipidemic, overweight men, and may therefore decrease the risk of cardiovascular events.

Adolescent↗

PubMed2006

Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men.

BACKGROUND: Increasing intakes of long-chain n-3 polyunsaturated fatty acids (PUFAs) can decrease markers of immunity. However, dose- and age-related responses have not been identified. OBJECTIVE: The objective was to determine the effects of different amounts of eicosapentaenoic acid (EPA) on innate immune outcomes in young and older males. DESIGN: In a controlled, double-blind study, healthy young and older men consumed 1 of 4 supplements provided as capsules: placebo (corn oil) or different amounts of an oil providing 1.35, 2.7, or 4.05 g EPA/d for 12 wk. Blood samples were collected at baseline and after 12 wk. RESULTS: EPA was incorporated in a linear dose-response fashion into plasma and mononuclear cell (MNC) phospholipids; incorporation was greater in the older men. EPA treatment did not alter neutrophil or monocyte phagocytosis, monocyte respiratory burst, or the production of inflammatory cytokines by MNCs in the young or older men. EPA treatment caused a dose-dependent decrease in neutrophil respiratory burst only in the older men. Increased incorporation of EPA into plasma or MNC phospholipids was associated with decreased production of prostaglandin E2 by MNCs from both young and older men. CONCLUSIONS: Older subjects incorporate EPA into plasma and MNC phospholipids more readily than do younger subjects. Other than prostaglandin E2 production, innate immune responses in young subjects are not affected by an EPA intake of < or =4.05 g/d. Older subjects are more sensitive to the immunologic effects of EPA, and the neutrophil respiratory burst is lower at higher EPA intakes.

Adolescent↗

PubMed2005

Diacylglycerol: efficacy and mechanism of action of an anti-obesity agent.

Obesity is at the forefront of global health issues and directly contributes to many chronic illnesses. Several dietary components show promise in the treatment of obesity, one of which is oil rich in diacylglycerols (DAGs). Present objectives are to examine scientific knowledge concerning DAG to assess evidence supporting the effects on substrate oxidation rates, body weight and fat mass, and blood lipids, and to assess safety, as well as elucidate potential mechanisms of action. DAG can be synthesized by an enzymatic process to produce mainly 1,3-isoform DAG. This 1,3-DAG oil is believed to have the ability to increase beta-oxidation, to enhance body weight loss, to suppress body fat accumulation, and to lower serum triacylglycerol levels postprandially. While certain animal and human studies indicate that consumption of 1,3-DAG has positive physiological effects, others report no effect. The mechanisms of action of DAG are suggested to decrease the resynthesis of chylomicrons as well as shunting them directly to the liver through the portal vein, where they are oxidized. This increased fat oxidation may influence control of food intake by increasing satiety. Further study into the precise mechanism is required to understand its effects. Safety studies show no risks in consuming a diet rich in DAG oil. Overall, consumption of oils with higher amounts of DAG, specifically 1,3-DAG, may be useful in the battle against obesity.

Animals↗

PubMed2004

n-3 polyunsaturated fatty acids and colon cancer prevention.

The incidence of colon cancer in industrialised countries has increased since the early 1970s. It is estimated that more than one-third of cases are associated with factors related to a Western diet. Both the type and amount of dietary fats consumed have been implicated in colon cancer aetiology. Recent studies have demonstrated that n-3 polyunsaturated fatty acids (PUFAs), commonly found in fish oil (FO), could prevent colon cancer development. Evidences show that n-3 PUFAs act at different stages of cancer development and through several mechanisms including the modulation of arachidonic acid-derived prostaglandin synthesis, and Ras protein and protein kinase C expression and activity. As a result, n-3 PUFAs limit tumour cell proliferation, increase apoptotic potential along the crypt axis, promote cell differentiation and possibly limit angiogenesis. The modulatory actions of n-3 PUFAs on the immune system and their anti-inflammatory effects might also play a role in reducing colon carcinogenesis. There remains, nevertheless, some ambiguity over the safety of n-3 PUFAs with respect to secondary tumour formation. However, it appears that n-3 PUFAs may be of use in colon cancer prevention.

Animals↗

PubMed2003

[Determination of energy expenditure in the clinical setting].

A patient's nutritional support is a critical part of his general health care scheme. It aims to prevent or correct malnutrition, reduce morbidity, length of hospital stay and treatment costs. It equally optimises the patient's convalescence and quality of life. An optimal support requires the nutritional evaluation of the patient which includes determination of the energy expenditure. Once the energy needs have been evaluated, the clinician is then able to treat any nutritional deficiencies. This article therefore looks at the different methods available for predicting and measuring energy expenditure. The clinical limitations of these techniques and particular cases encountered (intensive care unit, anorexia and severe obesity, geriatrics, HIV infection, etc) will also be discussed.

Critical Care↗