A practical approach to increasing intakes of n-3 polyunsaturated fatty acids: use of novel foods enriched with n-3 fats

ObjectivesTo assess the effects of providing a wide range of foodstuffs containing n-3 polyunsaturated fatty acids (PUFA), occurring naturally or from fortification, on intake and blood and tissue proportions of n-3 PUFA.DesignBefore/after dietary intervention study.SettingAdelaide, Australia.Subjects16 healthy males recruited from the community.InterventionsSubjects were provided with a range of foodstuffs naturally containing n-3 PUFA (fresh fish, canned fish, flaxseed meal, canola oil) and items fortified with fish oil (margarine spread, milk, sausages, luncheon meat, french onion dip). Food choices were left to the discretion of each subject. Intake was estimated by diet diary. Blood was collected at-2, 0, 2, and 4 weeks for fatty acid analysis.Main outcome measuresDietary intakes; plasma, platelet, and mononuclear cell phospholipid fatty acids.ResultsConsumption of n-3 PUFA increased significantly: alpha-linolenic acid (ALA) from 1.4 to 4.1 g/day (PConclusionIncorporating fish oil into a range of novel commercial foods provides the opportunity for wider public consumption of n-3 PUFA with their associated health benefits.SponsorshipDawes Scholarship, Royal Adelaide Hospital

A suplementação com ácido linoléico conjugado reduziu a gordura corporal em ratos Wistar Conjugated linoleic acid suplementation decreased the body fat in Wistar rats

O ácido linoléico conjugado, um conjunto de isômeros geométricos e de posição do ácido linoléico, vem sendo muito estudado devido ao seu efeito sobre a composição corporal, promovendo redução da massa gorda. O objetivo deste trabalho foi avaliar o efeito da suplementação com ácido linoléico conjugado sobre a composição corporal de ratos Wistar saudáveis em crescimento. Um total de 40 ratos, divididos em quatro grupos, foram suplementados diariamente durante três semanas com AdvantEdge® ácido linoléico conjugado (EAS TM) nas concentrações 1,0%, 2,0% e 4,0% sobre o consumo diário de dieta, constituindo, respectivamente, os grupos AE1, AE2 e AE4, e com ácido linoléico na concentração de 2% sobre o consumo diário de dieta, constituindo o grupo-controle. Os animais foram suplementados por meio de entubação orogástrica. Para a avaliação da composição corporal centesimal foi removido o conteúdo intestinal para obtenção da carcaça vazia. Em seguida, a carcaça foi congelada em nitrogênio líquido, fatiada, liofilizada, moída e armazenada a -25&deg;C, até o momento das determinações de umidade, cinzas, proteína bruta e gordura. O grupo AE1 apresentou maior consumo de dieta e ganho de peso, mas não diferiu quanto à eficiência alimentar dos demais grupos (p< 0,05). Em relação à composição corporal, constatou-se redução dos teores de gordura corporal dos grupos AE2 (11,2%) e AE4 (11,6%), quando comparados ao teor do grupo-controle (13,9%). A suplementação com ácido linoléico conjugado nas concentrações de 2,0% e 4,0% sobre o consumo diário de dieta promoveu redução de gordura corporal de 18,0% nos ratos Wistar.<br>Conjugated linoleic acid, a group of positional and geometric isomers of linoleic acid, has been greatly investigated due to its effect on body composition, mainly the reduction of body fat. The purpose of this study was to evaluate the effect of conjugated linoleic acid supplementation on the body composition of healthy, growing Wistar rats. Forty male Wistar rats were divided into 4 groups and supplemented daily for 3 weeks with AdvantEdge® conjugated linoleic acid (EAS TM) at concentrations of 1.0%, 2.0% and 4.0% of the daily feed intake, corresponding to groups AE1, AE2 and AE4, and with linoleic acid at 2.0% (control) corresponding to group C. The animals were supplemented via a stomach tube. For the body composition analyses, the gut contents were removed to obtain the empty carcass weight. The carcasses were then frozen in liquid nitrogen, chopped, dried, ground and stored at -25ºC, until analyzed for water, ash, protein and fat. The AE1 group showed higher feed intake and weight gain, but did not differ in food efficiency from the other groups (p< 0.05). In terms of body composition, body fat reduced in groups AE2 (11.2%) and AE4 (11.6%), as compared to the control (13.9%). Conjugated linoleic acid supplementation at a rate of 2.0% and 4.0% with respect to the daily feed intake, decreased body fat by 18.0% in Wistar rats

Understanding omega-3 polyunsaturated fatty acids

Current intakes of very long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are low in most individuals living in Western countries. A good natural source of these fatty acids is seafood, especially oily fish. Fish oil capsules contain these fatty acids also. Very long-chain omega-3 fatty acids are readily incorporated from capsules into transport (blood lipids), functional (cell and tissue), and storage (adipose) pools. This incorporation is dose-dependent and follows a kinetic pattern that is characteristic for each pool. At sufficient levels of incorporation, EPA and DHA influence the physical nature of cell membranes and membrane protein-mediated responses, lipid-mediator generation, cell signaling, and gene expression in many different cell types. Through these mechanisms, EPA and DHA influence cell and tissue physiology and the way cells and tissues respond to external signals. In most cases the effects seen are compatible with improvements in disease biomarker profiles or health-related outcomes. As a result, very long-chain omega-3 fatty acids play a role in achieving optimal health and in protection against disease. Long-chain omega-3 fatty acids not only protect against cardiovascular morbidity but also against mortality. In some conditions, for example rheumatoid arthritis, they may be beneficial as therapeutic agents. On the basis of the recognized health improvements brought about by long-chain omega-3 fatty acids, recommendations have been made to increase their intake. The plant omega-3 fatty acid, alpha-linolenic acid (ALA), can be converted to EPA, but conversion to DHA appears to be poor in humans. Effects of ALA on human health-related outcomes appear to be due to conversion to EPA, and since this is limited, moderately increased consumption of ALA may be of little benefit in improving health outcomes compared with increased intake of preformed EPA + DHA