Tous les acides gras saturés ont-ils le même effet métabolique ?

Fish Oil and Microalga Omega-3 as Dietary Supplements: A Comparative Study on Cardiovascular Risk Factors in High-Fat Fed Rats

Dietary supplementation with marine omega-3 polyunsaturated fatty acids (n-3 PUFA) can have beneficial effects on a number of risk factors for cardiovascular disease (CVD). We compared the effects of two n-3 PUFA rich food supplements (freeze-dried Odontella aurita and fish oil) on risk factors for CVD. Male rats were randomly divided into four groups of six animals each and fed with the following diets: control group (C) received a standard diet containing 7 % lipids; second group (HF high fat) was fed with a high-fat diet containing 40 % lipids; third group (HFFO high fat+fish oil) was fed with the high-fat diet supplemented with 0.5 % fish oil; and fourth group (HFOA high fat+O. aurita) received the high-fat diet supplemented with 12 % of freeze-dried O. aurita. After 8 weeks rats fed with the high-fat diet supplemented with O. aurita displayed a significantly lower bodyweight than those in the other groups. Both the microalga and the fish oil significantly reduced insulinemia and serum lipid levels. O. aurita was more effective than the fish oil in reducing hepatic triacyglycerol levels and in preventing high-fat diet-induced steatosis. O. aurita and fish oil also reduced platelet aggregation and oxidative status induced by high fat intake. After an OA supplementation, the adipocytes in the HFOA group were smaller than those in the HF group. Freeze-dried O. aurita showed similar or even greater biological effects than the fish oil. This could be explained by a potential effect of the n-3 PUFA but also other bioactive compounds of the microalgae.

[Relation between structure and function, of the cerebral artery "carotid" in laboratory rat submitted to atherogenic diet]

OBJECTIVE OF THE STUDY

The aim of our investigation was the study of the pathophysiology of the carotid artery in cases of nutritional stress in male atheroresistant Wistar rats.

MATERIALS AND METHODS

Were administered daily by gavage to experimental rats a high fat diet consisting of peanut oil, cholesterol (3%) and sodium cholate (1%). Throughout this experiment, we conducted monitoring of some biochemical parameters and the morpho-histopathology of the carotid cerebral artery. The results obtained are compared to those of control rats in the same experimental conditions.

RESULTS

We found that this fat diet resulted in experimental rats disruption of biochemical tests and tissular and cellular alterations in carotid wall. Indeed, the biochemical examination shows a significant increase of the parameters studied. Morphological examination revealed thickening of the carotid wall and histopathological examination of this artery, highlights the installation of a vascular remodeling from thickening of the intima-media to the installation of a probable atherosclerosis accompanied by a possible hyalinization and a net fibrosis.

CONCLUSION

At the end of this study, although notes that our fat diet could cause a metabolic disorder that can cause multiple tissue and cell damage observed in cerebral artery "carotid" of atheroresistant rats.

Short-term and mid-term effects of fasting and downset meal pattern on lipid profile in Iranian fasted women

It is not clear that whether the effects of fasting and downset meal pattern on lipid profile are limited only to Ramadan or do they remain after that month. The cohort study was conducted on 49 women aged 20-45 who worked at Shahid Motahari hospital in Isfahan. They put on groups of 23 consuming downset meal and 26 non-consuming downset meal persons. Serum triglyceride, cholesterol, LDL, and HDL were measured on the 3 days before the beginning, 3 and 30 days after the end of Ramadan. Repeated measure test was used to determine the changes during times and the interaction effects between times and nocturnal eating pattern. This study showed that fasting causes some short-term and mid-term changes in triglyceride and HDL that is mostly attributable to changes in dietary habits during Ramadan, rather than downset meal pattern.

Seasonal and stage of lactation effects on milk fat composition in northern Victoria

Effect of herd nutrition, time of year and season of calving on milk fat composition and physical properties were examined on irrigated commercial dairy farms in northern Victoria that made use of split-calving and a diverse range of feeding systems. Twenty-four farms were included in the study, and from each farm, morning and evening milk samples were collected from 16 cows that calved in autumn and 16 cows that calved in spring. There were no significant effects of season of calving on the concentration of fatty acids or phospholipids in milk fat, but there were interactions between season of calving and time of year (P < 0.001). These differences could be attributed to changes in energy balance and body condition with stage of lactation. The phospholipids comprising mainly phosphotidylcholine (PC), phosphtidylethanolamine (PE) and sphingomyelin (SP) also varied, with PC and PE being highest in late lactation and SP lowest during peak and mid lactation for both calving groups. Milk fat colour and the concentrations of free fatty acids were more influenced by factors associated with time of year rather than stage of lactation. Milk fat colour in particular showed strong seasonal variation being distinctly lighter in summer–early autumn when compared with rest of the year. Increasing the amount of concentrates fed was associated with decreases in short-chain fatty acid concentration and increases in the solid fat content of milk fat. Variations in nutritional management practices had only small (non-significant) effects on fat composition.