K
Kev
Guest
Below is a recent study demonstrating some of the differences between fish oil and flax. Below that
is a study demonstrating some adverse effects from GLA in Borage oil, and presumably this could
include Evening Primrose oil. Fish oil consistently demonstrates positive effects.
Anyone care to comment on this?
J Nutr. 1996 Sep;126(9):2130-40.
Normal subjects consuming physiological levels of 18:3(n-3) and 20:5(n-3) from flaxseed or fish oils
have characteristic differences in plasma lipid and lipoprotein fatty acid levels.
Layne KS, Goh YK, Jumpsen JA, Ryan EA, Chow P, Clandinin MT. Nutrition and Metabolism Research
Group, University of Alberta, Edmonton, Canada.
The study assessed the effect of low doses of fatty acids from fish or flaxseed oil on plasma lipid
concentrations in normal humans consuming diets with either high (0.87, n = 11) or low (0.48, n =
15) dietary polyunsaturated/saturated fatty acid (P/S) ratios. The dose of (n-3) fatty acids
reflected an (n-3) intake that could easily be attained by selection of foods in a normal diet. The
individuals were initially supplemented with olive oil [35 mg 18:1/(kg body weight.d)], and then
were randomly assigned to either flaxseed or fish oil [35 mg 18:3(n-3) or 35 mg 20:5(n-3) +
22:6(n-3)/(kg body weight.d), respectively] treatments. Participants consumed each oil supplement
for 3 mo. Blood samples were drawn for analysis at the end of each 3-mo period. Plasma
triacylglycerol, total, LDL and HDL cholesterol concentrations, and lipoprotein fatty acid
concentrations are shown. Fish oil reduced plasma triacylglycerol and increased lipoprotein
levels of 20:5(n-3) and 22:6(n-3). The flaxseed oil did not alter plasma triacylglycerol level
and produced small changes in 20:5(n-3) and 22:6(n-3) concentrations. Total, LDL and HDL
cholesterol levels were not affected by either (n-3) fatty acid. Significant differences in
plasma triacylglycerol concentrations and total and LDL cholesterol levels were found between the
two dietary P/S groups after all oil treatment periods. Levels of 18:3(n-3),
23:4(n-6), 20:5(n-3), and 22:6(n-3) in LDL were also different in high vs. low dietary P/S groups
for all oil treatments and in the VLDL for the olive oil and fish oil supplementation. This study
indicates that low intake of purified fish oil induces changes in plasma triacylglycerol,
20:5(n-3) levels in VLDL, LDL, and HDL, and 22:6(n-3) levels in LDL and HDL that are apparent
after 3 mo and which might influence atherogenicity of lipoprotein particles in normal
free-living individuals. Publication Types:
* Clinical Trial
* Randomized Controlled Trial PMID: 8814201
Endocr Regul. 2002 Nov;36(4):143-9. Comparison of the extrapancreatic action of gamma-linolenic
acid and n-3 PUFAs in the high fat diet-induced insulin resistance.
Simoncikova P, Wein S, Gasperikova D, Ukropec J, Certik M, Klimes I, Sebokova E.
Department of Biochemical Technology, Faculty of Chemical and Food Technology, Slovak University of
Technology, 812 37 Bratislava, Slovakia. OBJECTIVE: The effect of dietary borage oil (rich in the
gamma-linolenic acid [GLA]) on insulin sensitivity and lipid metabolism was compared with that of
fish oil (rich in n-3 polyunsaturated fatty acids [PUFAs]) in high fat (HF) diet-induced insulin
resistance (IR) of rats. METHODS: Male Wistar rats were fed ad libitum for 3 weeks a standard
laboratory chow (Controls) or high fat diet consisting of 70-cal % fat. In addition, a group of rats
was fed high fat (HF) diet where a part of saturated fat was replaced with fish oil as a source of
n-3 PUFAs (HF+FO), or borage oil as a source of GLA (HF+GLA). In vivo insulin action was assessed by
the euglycemic hyperinsulinemic clamp. Glucose, insulin, free fatty acids (FFA), triglycerides (Tg)
and glycerol levels in blood and tissue depots were also measured. RESULTS: Increased levels of Tg,
FFA and glycerol in circulation after HF diet were accompanied by their raised accumulation in
insulin sensitive tissues. FO feeding lowered the concentration of all lipids in serum and prevented
their accumulation in both tissues. On the other hand GLA supplementation into the high fat diet did
not suppress increased levels of Tg, FFA and glycerol in circulation and tissue depots as well. FO
feeding significantly reduced HF diet-induced in vivo IR, while GLA supplementation did not improve
the in vivo insulin sensitivity in HF diet induced insulin resistance. CONCLUSIONS: 1. Substitution
of FO into the high fat diet led to an improvement of in vivo insulin action; 2. this insulin
sensitizing effect of FO was accompanied by a decrease of circulating Tg, FFA and glycerol levels in
the postprandial state and by a lower lipid content in liver and skeletal muscle. 3. on the
opposite, GLA treatment failed to improve in vivo insulin action; and 4. was associated with an
adverse effect on lipid levels both in circulation and tissue depots. PMID: 12466014
is a study demonstrating some adverse effects from GLA in Borage oil, and presumably this could
include Evening Primrose oil. Fish oil consistently demonstrates positive effects.
Anyone care to comment on this?
J Nutr. 1996 Sep;126(9):2130-40.
Normal subjects consuming physiological levels of 18:3(n-3) and 20:5(n-3) from flaxseed or fish oils
have characteristic differences in plasma lipid and lipoprotein fatty acid levels.
Layne KS, Goh YK, Jumpsen JA, Ryan EA, Chow P, Clandinin MT. Nutrition and Metabolism Research
Group, University of Alberta, Edmonton, Canada.
The study assessed the effect of low doses of fatty acids from fish or flaxseed oil on plasma lipid
concentrations in normal humans consuming diets with either high (0.87, n = 11) or low (0.48, n =
15) dietary polyunsaturated/saturated fatty acid (P/S) ratios. The dose of (n-3) fatty acids
reflected an (n-3) intake that could easily be attained by selection of foods in a normal diet. The
individuals were initially supplemented with olive oil [35 mg 18:1/(kg body weight.d)], and then
were randomly assigned to either flaxseed or fish oil [35 mg 18:3(n-3) or 35 mg 20:5(n-3) +
22:6(n-3)/(kg body weight.d), respectively] treatments. Participants consumed each oil supplement
for 3 mo. Blood samples were drawn for analysis at the end of each 3-mo period. Plasma
triacylglycerol, total, LDL and HDL cholesterol concentrations, and lipoprotein fatty acid
concentrations are shown. Fish oil reduced plasma triacylglycerol and increased lipoprotein
levels of 20:5(n-3) and 22:6(n-3). The flaxseed oil did not alter plasma triacylglycerol level
and produced small changes in 20:5(n-3) and 22:6(n-3) concentrations. Total, LDL and HDL
cholesterol levels were not affected by either (n-3) fatty acid. Significant differences in
plasma triacylglycerol concentrations and total and LDL cholesterol levels were found between the
two dietary P/S groups after all oil treatment periods. Levels of 18:3(n-3),
23:4(n-6), 20:5(n-3), and 22:6(n-3) in LDL were also different in high vs. low dietary P/S groups
for all oil treatments and in the VLDL for the olive oil and fish oil supplementation. This study
indicates that low intake of purified fish oil induces changes in plasma triacylglycerol,
20:5(n-3) levels in VLDL, LDL, and HDL, and 22:6(n-3) levels in LDL and HDL that are apparent
after 3 mo and which might influence atherogenicity of lipoprotein particles in normal
free-living individuals. Publication Types:
* Clinical Trial
* Randomized Controlled Trial PMID: 8814201
Endocr Regul. 2002 Nov;36(4):143-9. Comparison of the extrapancreatic action of gamma-linolenic
acid and n-3 PUFAs in the high fat diet-induced insulin resistance.
Simoncikova P, Wein S, Gasperikova D, Ukropec J, Certik M, Klimes I, Sebokova E.
Department of Biochemical Technology, Faculty of Chemical and Food Technology, Slovak University of
Technology, 812 37 Bratislava, Slovakia. OBJECTIVE: The effect of dietary borage oil (rich in the
gamma-linolenic acid [GLA]) on insulin sensitivity and lipid metabolism was compared with that of
fish oil (rich in n-3 polyunsaturated fatty acids [PUFAs]) in high fat (HF) diet-induced insulin
resistance (IR) of rats. METHODS: Male Wistar rats were fed ad libitum for 3 weeks a standard
laboratory chow (Controls) or high fat diet consisting of 70-cal % fat. In addition, a group of rats
was fed high fat (HF) diet where a part of saturated fat was replaced with fish oil as a source of
n-3 PUFAs (HF+FO), or borage oil as a source of GLA (HF+GLA). In vivo insulin action was assessed by
the euglycemic hyperinsulinemic clamp. Glucose, insulin, free fatty acids (FFA), triglycerides (Tg)
and glycerol levels in blood and tissue depots were also measured. RESULTS: Increased levels of Tg,
FFA and glycerol in circulation after HF diet were accompanied by their raised accumulation in
insulin sensitive tissues. FO feeding lowered the concentration of all lipids in serum and prevented
their accumulation in both tissues. On the other hand GLA supplementation into the high fat diet did
not suppress increased levels of Tg, FFA and glycerol in circulation and tissue depots as well. FO
feeding significantly reduced HF diet-induced in vivo IR, while GLA supplementation did not improve
the in vivo insulin sensitivity in HF diet induced insulin resistance. CONCLUSIONS: 1. Substitution
of FO into the high fat diet led to an improvement of in vivo insulin action; 2. this insulin
sensitizing effect of FO was accompanied by a decrease of circulating Tg, FFA and glycerol levels in
the postprandial state and by a lower lipid content in liver and skeletal muscle. 3. on the
opposite, GLA treatment failed to improve in vivo insulin action; and 4. was associated with an
adverse effect on lipid levels both in circulation and tissue depots. PMID: 12466014