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Health and Disease, sessions held on 19 and 21 September on various topics
Session on September 19, 2011
Vincent Richard (Concordia University, Canada) presented results of the involvement of lipid metabolism in the aging process, studied in yeasts which served as a model system. Their findings revealed two different ways for delaying aging by altering cellular lipid dynamics and thereby impairing the age-related programmed necrotic death pathway.
The presentation of Professor Kazuo Miyashita (Hokkaido University, Japan) revealed the effects of fucoxanthin, a natural antioxidant with a specific allenic bound, as an anti-obesity and anti-diabetic agent. Fucoxanthin is present in brown seaweed and micro algae. Studies on gene expression show that it improved insulin resistance and inhibited the interaction between adipose tissue and the invasion of macrophages, thereby reducing inflammation.
Paula Lopes (University of Lisbon, Portugal) presented her results of the use of conjugated linoleic acid (CLA) as a body weight reducing agent. Studies with normal and obese rats showed that the supplementation of a mixture of the most common isomers of CLA to a palm oil based diet (source of C16:0) or an ovine fat diet (source of C18:0) did differ. CLA had a contrasting effect of hepatic cell death depending on the background source of dietary fat. Moreover, CLA added to palm oil diet improved the adipocytokines profile and other inflammatory markers in obese rats compared to CLA added to the ovine fat diet. Therefore, she concluded that CLA is not feasible as a fat reducing agent in Western society, where high intake of saturated fat from animal fat is prevalent.
Dr Kalanithi Nesaretnam (Malaysian Palm Oil Board, Malaysia) presented results of her research on the involvement of tocotrienols on breast cancer. Tocotrienols are only present in palm oil, palm kernel and rice bran oils, whereas tocopherols are present in most vegetable oils. Data suggest that tocotrienols increased the survival rates from 95 to 98% in women just diagnosed with breast cancer. Future research will test the efficacy of tocotrienols in women in an advanced stage of breast cancer.
Session on September 21, 2011
This session was opened by associate professor Jeff Volek (University of Connecticut, USA). He presented his view on the unintended consequences of decreasing intake of dietary saturated fatty acids (SAFA): an overconsumption of carbohydrates and categorizing foods that naturally contain saturated fats as unhealthy. Based on observational studies, he showed that there is no association between dietary fatty acids and heart diseases and/or mortality, whereas there is evidence that the risk for chronic diseases such as cardiovascular diseases and diabetes is increased if saturated in plasma lipids are increased. He emphasised that the intake of saturated fatty acids is poorly related to their amount in plasma; nevertheless high amounts of dietary carbohydrates are a determining factor of the amount of saturated fatty acids in plasma due to de novo lipogenesis (i.e. the production of SAFA from dietary carbohydrates). He concluded that the amount of carbohydrates in the diet is important when considering the impact of saturated fatty acids in the diet.
The next speaker, Dr George van Aken (NIZO Food Research, The Netherlands), presented results from modelling studies on how fat consumption and formulation affect absorption and food intake. Our body is designed to control efficient absorption and control food intake in order to avoid that nutrients will enter the colon. Several feedback mechanisms are therefore present in the stomach and the intestines. Fat ingestion can be affected by emulsifiers through obstruction of the digestive enzymes and by colloidal destabilization processes in the stomach.
Dr Cécile Vors (INRA, France) presented results of fat emulsification and the effect on postprandial lipemia and exogenous lipid oxidation in healthy normal weight and obese subjects. Results indicated that non-emulsified spread fat resulted in a latter peak of chylomicrons during digestion compared with emulsified fats. These effects were more pronounced in obese than in lean subjects. Moreover, the appearance of labelled carbon (13C) in breath was earlier and higher after providing the emulsified fat in lean and obese subjects compared to the non-emulsified fat. Fat structuring can thus be used to control postprandial lipemia and lipid oxidation.
Dr Marie-Caroline Michalski (INRA, France) gave a presentation of the role of gut-derived endotoxemia in low-grade inflammation induced by high fat diets. A potential mechanism for the development of low-grade inflammation is the role of alterations in the composition of gut macrobiotic and the absorption of gut-derived proinflammatory endotoxins (lipopolysaccharides). Based on studies in rats and human she concluded that excessive fat intake induced endotoxemia and these effects were influenced by both fat structure and the composition of dietary fats used.
The final presentation of this congress on health and diseases came from Professor Terry Yanagati (Saga University, Japan) and he discussed the use of functional lipids in the prevention of metabolic syndrome. Dietary phospholipids contribute to 3-8% of the fat intake and they possess different functions than dietary triacylglycerols. Phosphatidylcholine enriched with DHA and phosphatidylinositol are examples of functional lipids that can exert beneficial effects with regard to the prevention of the metabolic syndrome.
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