Effect of dietary animal products obtained from flaxseed feed animals on red blood cell fatty acid composition, weight and plasma lipid parameters in obese human
Résumé
The Fatty Acid (FA) composition of the diet changed significantly during the explosion of obesity since the 1960th . Based on mechanistic and epidemiological datas, the question of the relationship between the qualitative dietary PUFA evolution and obesity development is raised, precisely when the decrease of dietary SFA / PUFA ratio is almost associated by a large increase of dietary n-6 / n-3 FA ratio. In the present double blind trial, we studied the effects on 160 obese (BMI>30) volunteers of an experimental diet rich in animal fat with a high SFA / PUFA ratio but a low n-6 / n-3 ratio, using animal products obtained from flaxseed fed animals. The control diet provided less animal fat, a lower SFA /PUFA ratio and a higher n-6 / n-3 ratio. Both regimen excluded seafood. In the experimental group, we observed a significant increase of ALA content of the redblood cells, a slight increase of the EPA and DHA derivatives, whereas a significant reduction ofEPA and DHA content appeared in the control group. Between groups now, the content difference was significant for the three n-3 fatty acids in RBC. This demonstrates that the plasma status of EPA and DHA can be maintain without fish, but when using products from flaxseed fed animals. Over the period of the regimens, we noted a significant reduction of weight, Body Mass Index (BMI) and hip circumference inside both groups of volunteers. However, no significant difference was observed between the control group and the experimental group. Interestingly, 150 days after the end of the regimens, we noted a significant weight gain in the control group, whereas no significant weight gain was observed in the experimental group. This was also observed for the BMI and hip circumference. Moreover, significant differences for the BMI (P < 0.05) and the weight (P = 0.05) occurred between the two groups, showing in both cases a lower increase in the experimental group. We do not observe any difference between groups for total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides. This is a novel result when considering that the experimental regimen exhibited (i) a higher level of saturated FA (31% FA vs 24% ) (ii) a lower polyunsaturated/saturated ratio (P/S) (0.3 vs 0.7) and (iii) a higher amount of animal lipids (76% vs 49%), as compared to the control regimen. None of these characteristics causes any deleterious effect on the blood lipid parameters, suggesting that the saturates content and the P/S ratio are not as important as the fine n-6 and n-3 fatty acids composition.