The Consumption of Food Products from Linseed-Fed Animals Maintains Erythrocyte Omega-3 Fatty Acids in Obese Humans
The Consumption of Food Products from Linseed-Fed Animals Maintains Erythrocyte Omega-3 Fatty Acids in Obese Humans
Year: 2010
Authors: Legrand, P. Schmitt, B. Mourot, J. Catheline, D. Chesneau, G. Mireaux, M. Kerhoas, N. Weill, P.
Publication Name: Lipids
Publication Details: Volume 45; Pages 11 – 19.
Abstract:
Based on mechanistic and epidemiological data, we raise the question of the relationship between qualitative dietary polyunsaturated fatty acids (PUFA) changes and increase in obesity. In this double-blind trial, we studied the effects on 160 overweight volunteers (body mass index, BMI, 30) of a 90 days experimental diet rich principally in animal fat with a low PUFA/saturated fatty acid (SFA) ratio but a low n6/n3 ratio, using animal products obtained from linseed-fed animals. The control diet provided less animal fat, a higher PUFA/SFA ratio and a higher n6/n3 ratio. Both diets excluded seafood. In the experimental group, we observed a significant increase in red blood cell (RBC) alpha-linolenic acid content and a slight increase in EPA and DHA derivatives, while in the control group we observed a significant reduction in EPA and DHA content. Between groups now, the difference in the three n3 fatty acids changes in RBC was significant. This demonstrates that plasma EPA and DHA levels can be maintained without fish if products from linseed-fed animals are used. During the diets, we noted a significant reduction in weight, BMI and hip circumference within 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 trial (at day 240), 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 in BMI (P < 0.05) and weight (P = 0.05) appeared between the two groups, showing in both cases a smaller increase in the experimental group. During the 90 days trial, we did not observe any differences between groups in terms of total cholesterol, HDL cholesterol, LDL cholesterol or triglycerides, suggesting that the saturate content and the P/S ratio are not as important as the n6 and n3 fatty acid composition. (Authors abstract)
Obesity is a multifactorial disease. In addition to energy imbalance, different aspects of lipid metabolism such as lipid synthesis, transport, storage and catabolism are also implied in obesity development. Polyunsaturated fatty acids (PUFA) may play a qualitative role, which is less established. While n-6 PUFA are now well known as activators of adipose tissue development and their dietary excess is suspected to favor childhood adiposity and adult adiposity, n-3 PUFA seem to play a more favorable role, acting against different mechanisms leading to obesity. n-3 PUFA seem to limit metabolic syndrome and type 2 diabetes. Consumption data show that the linoleic acid (LNA) to a-linolenic acid (ALA) ratio has increased by approximately three times to reach a range of 12�25 in most of the western diets. In this double-blind trial, the effects on volunteers of a 90 days experimental diet rich in animal fat with both low PUFA/SFA and low n6/n3 ratios, using principally animal products obtained from linseed (flaxseed)-fed animals. The control diet provided less animal fat, a higher value for the PUFA/SFA ratio and a higher value for the n-6/n-3 ratio. The volunteers were overweight or obese (body mass index, BMI of 31). The main results were: (1) Plasma EPA and DHA levels can be maintained without fish, if using products from linseed-fed terrestrial animals. (2) During the diets, a significant reduction in weight, BMI, and hip circumference within both groups of volunteers, but no significant difference was observed between the control group and the experimental group. However, the experimental diet limited weight recovery after the end of the trial. (3) No comparative deleterious effect (on plasma lipid parameters) was observed between diets, suggesting that the n-6/n-3 ratio is as important as the SFA level. Another observation was an increase in the ALA content of RBC in the experimental group, whereas it did not vary in the control group. This increase in ALA is mainly due to the dietary animal products obtained from linseed-fed animals but also from linseed flour and bread included in the experimental diet. The increase in EPA and DHA content in the RBC were impressive. These contents decreased significantly in the control group, whereas they were maintained in the experimental group. Maintaining the EPA and DHA levels in the RBC in the experimental group, without consuming fish and other seafood during the trial, constitutes the major result of this study. This demonstrates the efficiency of the terrestrial animal vector for providing EPA and DHA to humans, when the animals receive small amounts of the precursor ALA alone (linseed-fed animals). This can be mainly explained by the direct intake of EPA and DHA contained in the animal products of the experimental diet since these derivatives are synthesized from ALA by the linseed-fed animals during their growth. The study also showed a decrease in EPA and DHA derivatives in the control group, suggesting (at least in the absence of fish consumption) that the average ALA intake in France is not sufficient to maintain correct EPA and DHA levels by ALA conversion alone, especially with a high dietary LNA/ALA ratio. The results obtained at day 240 (in only 72% of the day 90 population) showed a weight gain in the control group, whereas no weight gain was seen in the experimental group. Between groups, the BMI was significantly lower at day 240 in the experimental group and weight tended to be lower in the experimental group than in the control group. The results suggest the enrichment of tissues in n-3 fatty acids improves various metabolic syndrome parameters. Observing the inhibiting effect on weight gain recovery in the long term after the end of the trial is a new and interesting observation. The results in terms of plasma lipid parameters suggest that a diet containing 76% animal lipids (experimental diet) does not appear to be more deleterious than a diet containing 49% animal lipids only (control diet). (Editors comments)
Obesity is a multifactorial disease. In addition to energy imbalance, different aspects of lipid metabolism such as lipid synthesis, transport, storage and catabolism are also implied in obesity development. Polyunsaturated fatty acids (PUFA) may play a qualitative role, which is less established. While n-6 PUFA are now well known as activators of adipose tissue development and their dietary excess is suspected to favor childhood adiposity and adult adiposity, n-3 PUFA seem to play a more favorable role, acting against different mechanisms leading to obesity. n-3 PUFA seem to limit metabolic syndrome and type 2 diabetes. Consumption data show that the linoleic acid (LNA) to a-linolenic acid (ALA) ratio has increased by approximately three times to reach a range of 12�25 in most of the western diets. In this double-blind trial, the effects on volunteers of a 90 days experimental diet rich in animal fat with both low PUFA/SFA and low n6/n3 ratios, using principally animal products obtained from linseed (flaxseed)-fed animals. The control diet provided less animal fat, a higher value for the PUFA/SFA ratio and a higher value for the n-6/n-3 ratio. The volunteers were overweight or obese (body mass index, BMI of 31). The main results were: (1) Plasma EPA and DHA levels can be maintained without fish, if using products from linseed-fed terrestrial animals. (2) During the diets, a significant reduction in weight, BMI, and hip circumference within both groups of volunteers, but no significant difference was observed between the control group and the experimental group. However, the experimental diet limited weight recovery after the end of the trial. (3) No comparative deleterious effect (on plasma lipid parameters) was observed between diets, suggesting that the n-6/n-3 ratio is as important as the SFA level. Another observation was an increase in the ALA content of RBC in the experimental group, whereas it did not vary in the control group. This increase in ALA is mainly due to the dietary animal products obtained from linseed-fed animals but also from linseed flour and bread included in the experimental diet. The increase in EPA and DHA content in the RBC were impressive. These contents decreased significantly in the control group, whereas they were maintained in the experimental group. Maintaining the EPA and DHA levels in the RBC in the experimental group, without consuming fish and other seafood during the trial, constitutes the major result of this study. This demonstrates the efficiency of the terrestrial animal vector for providing EPA and DHA to humans, when the animals receive small amounts of the precursor ALA alone (linseed-fed animals). This can be mainly explained by the direct intake of EPA and DHA contained in the animal products of the experimental diet since these derivatives are synthesized from ALA by the linseed-fed animals during their growth. The study also showed a decrease in EPA and DHA derivatives in the control group, suggesting (at least in the absence of fish consumption) that the average ALA intake in France is not sufficient to maintain correct EPA and DHA levels by ALA conversion alone, especially with a high dietary LNA/ALA ratio. The results obtained at day 240 (in only 72% of the day 90 population) showed a weight gain in the control group, whereas no weight gain was seen in the experimental group. Between groups, the BMI was significantly lower at day 240 in the experimental group and weight tended to be lower in the experimental group than in the control group. The results suggest the enrichment of tissues in n-3 fatty acids improves various metabolic syndrome parameters. Observing the inhibiting effect on weight gain recovery in the long term after the end of the trial is a new and interesting observation. The results in terms of plasma lipid parameters suggest that a diet containing 76% animal lipids (experimental diet) does not appear to be more deleterious than a diet containing 49% animal lipids only (control diet). (Editors comments)
