Circulating triacylglycerol and apoE levels in response to EPA and docosahexaenoic acid supplementation in adult human subjects. Comparison of the effects of linseed oil and different doses of fish oil on mononuclear cell function in healthy human subjects. Docosahexaenoic acid supplementation in vegetarians effectively increases omega-3 index: A randomized trial The effect of dietary arachidonic acid on plasma lipoprotein distributions, apoproteins, blood lipid levels, and tissue fatty acid composition in humans Stearic, oleic, and linoleic acids have comparable effects on markers of thrombotic tendency in healthy human subjects. Plant- and marine-derived n-3 polyunsaturated fatty acids have differential effects on fasting and postprandial blood lipid concentrations and on the susceptibility of LDL to oxidative modification in moderately hyperlipidemic subjects. Dietary supplementation with eicosapentaenoic acid, but not with other long-chain n-3 or n-6 polyunsaturated fatty acids, decreases natural killer cell activity in healthy subjects aged >55 y. Highly purified eicosapentaenoic acid and docosahexaenoic acid in humans have similar triacylglycerol-lowering effects but divergent effects on serum fatty acids. Fatty acid saturation of the diet and plasma lipid concentrations, lipoprotein particle concentrations, and cholesterol efflux capacity. Essential fatty acid requirements in infancy. Fatty acid composition of skeletal muscle reflects dietary fat composition in humans. Effect of dietary alpha-linolenic acid on thrombotic risk factors in vegetarian men. Supplementation with an algae source of docosahexaenoic acid increases (n-3) fatty acid status and alters selected risk factors for heart disease in vegetarian subjects. Novel soybean oils with different fatty acid profiles alter cardiovascular disease risk factors in moderately hyperlipidemic subjects. Effect of a low-fat diet on fatty acid composition in red cells, plasma phospholipids, and cholesterol esters: investigation of a biomarker of total fat intake. Decreasing linoleic acid with constant alpha-linolenic acid in dietary fats increases (n-3) eicosapentaenoic acid in plasma phospholipids in healthy men. Dietary substitution with an alpha-linolenic acid-rich vegetable oil increases eicosapentaenoic acid concentrations in tissues. Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on immune cell composition and function in healthy humans. Dietary supplementation with gamma-linolenic acid alters fatty acid content and eicosanoid production in healthy humans. Total fat intake modifies plasma fatty acid composition in humans. Alpha-linolenic acid in rapeseed oil partly compensates for the effect of fish restriction on plasma long chain n-3 fatty acids. Molecular order and dynamics in bilayers consisting of highly polyunsaturated phospholipids. Aspirin use and reduced risk of fatal colon cancer. Increased arachidonate in lipids after administration to man: Effects on prostaglandin biosynthesis Arachidonic Acid Supplementation Decreases P300 Latency and Increases P300 Amplitude of Event-Related Potentials in Healthy Elderly Men Antithetic relationship of dietary arachidonic acid and eicosapentaenoic acid on eicosanoid production in vivo. Encapsulated fish oil enriched in alpha-tocopherol alters plasma phospholipid and mononuclear cell fatty acid compositions but not mononuclear cell functions. Essential Fatty Acid Deficiency During Total Parenteral Nutrition A study of evening primrose seed oil in atopic asthma. Black currant seed oil and fish oil supplements differ in their effects on fatty acid profiles of plasma lipids, and concentrations of serum total and lipoprotein lipids, plasma glucose and insulin. Dietary fatty acid supplementation alters stress reactivity and performance in man. Co-supplementation of healthy women with fish oil and evening primrose oil increases plasma docosahexaenoic acid, gamma-linolenic acid and dihomo-gamma-linolenic acid levels without reducing arachidonic acid concentrations. The influence of different combinations of gamma-linolenic, stearidonic and eicosapentaenoic acids on the fatty acid composition of blood lipids and mononuclear cells in human volunteers. Sea buckthorn berry oil inhibits platelet aggregation.
High doses of n-3 PUFA found in fish oils can reduce the circulating concentration of triacylglycerol ( TG ) , which may contribute to the positive impact of these fatty acids on the risk of CVD . The present study aim ed to establish the differential impact of EPA and docosahexaenoic ( DHA ) on plasma lipids and apo in adults . Forty-two normolipidaemic adult subjects completed a double-blind placebo controlled parallel study , receiving an EPA-rich oil ( 4.8 g EPA/d ) , DHA-rich oil ( 4.9 g DHA/d ) or olive oil as control , for a period of 4 weeks . No effects of treatment on total cholesterol , LDL-cholesterol or HDL-cholesterol were evident . There was a significant 22 % reduction in TG level relative to the control value following the DHA treatment ( P=0.032 ) , with the 15 % decrease in the EPA group failing to reach significance ( P=0.258 ) . There were no significant inter-group differences in response to treatment for plasma apoA1 , -C3 or -E levels , although a significant 15 % within-group increase in apoE was evident in the EPA ( P=0.006 ) and DHA ( P=0.003 ) groups . In addition , a within-group decrease in the apoA1:HDL-cholesterol ratio was observed in the DHA group , suggesting a positive impact of DHA on HDL particle size . The DHA intervention result ed in a significant increase in the proportion of EPA P=0.000 and DHA P=0.000 in plasma phospholipids , whilst significant increases in EPA P=0.000 and docosapentaenoic acid P=0.002 , but not DHA P=0.193 , were evident following EPA supplementation ( P<0.05 ) . Our present results indicate that DHA may be more efficacious than EPA in improving the plasma lipid profile Studies on animal and human subjects have shown that greatly increasing the amount of linseed ( also known as flaxseed ) oil ( rich in the n-3 polyunsaturated fatty acid ( PUFA ) alpha-linolenic acid ( ALNA ) ) or fish oil ( FO ; rich in the long-chain n-3 PUFA eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) ) in the diet can decrease a number of markers of immune function . The immunological effects of more modest doses of n-3 PUFA in human subjects are unclear , dose-response relationships between n-3 PUFA supply and immune function have not been established and whether ALNA has the same effects as its long-chain derivatives is not known . Therefore , the objective of the present study was to determine the effect of enriching the diet with different doses of FO or with a modest dose of ALNA on a range of functional responses of human monocytes and lymphocytes . In a r and omised , placebo-controlled , double-blind , parallel study , forty healthy males aged 18 - 39 years were r and omised to receive placebo or 3.5 g ALNA/d or 0.44 , 0.94 or 1.9 g (EPA+DHA)/d in capsules for 12 weeks . The EPA : DHA ratio in the FO used was 1.0:2.5 . ALNA supplementation increased the proportion of EPA but not DHA in plasma phospholipids . FO supplementation decreased the proportions of linoleic acid and arachidonic acid and increased the proportions of EPA and DHA in plasma phospholipids . The interventions did not alter circulating mononuclear cell subsets or the production of tumour necrosis factor-alpha , interleukin ( IL ) 1beta , IL-2 , IL-4 , IL-10 or interferon-gamma by stimulated mononuclear cells . There was little effect of the interventions on lymphocyte proliferation . The two higher doses of FO result ed in a significant decrease in IL-6 production by stimulated mononuclear cells . It is concluded that , with the exception of IL-6 production , a modest increase in intake of either ALNA or EPA+DHA does not influence the functional activity of mononuclear cells . The threshold of EPA+DHA intake that results in decreased IL-6 production is between 0.44 and 0.94 g/d Low red blood cell ( RBC ) membrane content of FPA+DHA ( hereafter called omega-3 index ) has recently been described as an indicator for increased risk of death from coronary heart disease . The relationship between plasma and RBC FA , focusing on omega-3 index , and the response to DHA supplementation were investigated in a double-blind , r and omized , placebo-controlled , intervention study . Healthy vegetarians ( 87 f , 17 m ) consumed daily a microalgae oil from Ulkenia sp. ( 0.94 g DHA/d ) or olive oil ( placebo ) for 8 wk . DHA supplementation significantly increased DHA in RBC total lipids ( 7.9 vs. 4.4 wt% ) , in RBC PE ( 12.1 vs. 6.5 wt% ) , in RBC PC ( 3.8 vs. 1.4 wt% ) , and in plasma phospholipids ( PL ) ( 7.4 vs. 2.8 wt% ) , whereas EPA levels rose to a much lesser extent . Microalgae oil supplementation increased the omega-3 index from 4.8 to 8.4 wt% . After intervention , 69 % of DHA-supplemented subjects ( but no subject of the placebo group ) reached an omega-3 index above the desirable value of 8 wt% . Omega-3 index and EPA+DHA levels in RBC PE , RBC PC , and plasma PL were closely correlated ( r always > 0.9 ) . We conclude that an 8-wk supplementation with 0.94 g DHA/d from microalgae oil achieves a beneficial omega-3 index of ≥8 % in most subjects with low basal EPA+DHA status . RBC total FA analyses can be used instead of RBC lipid fraction analyses for assessing essential FA status , e.g. , in clinical studies Normal healthy male volunteers ( n=10 ) were fed diets ( high-AA ) containing 1.7 g/d of arachidonic acid ( AA ) for 50 d. The control ( low-AA ) diet contained 210 mg/d of AA . Dietary AA had no statistically significant effect on the blood cholesterol levels , lipoprotein distribution , or apoprotein levels . Adipose tissue fatty acid composition was not influenced by AA feeding . The plasma total fatty acid composition was markedly enriched in AA after 50 d ( P<0.005 ) . The fatty acid composition of plasma lipid fractions , cholesterol esters , triglycerides , free fatty acids , and phospholipid ( PL ) showed marked differences in the degree of enrichment in AA . The PL plasma fraction from the subjects consuming the low-AA diet contained 10.3 % AA while the subjects who consumed the high-AA diet had plasma PL fractions containing 19.0 % AA . The level of 22:4n-6 also was different ( 0.67 to 1.06 % ) in the plasma PL fraction after 50 d of AA feeding . After consuming the high-AA diet , the total red blood cell fatty acid composition was significantly enriched in AA which mainly replaced linoleic acid . These results indicate that dietary AA is incorporated into tissue lipids , but selectively into different tissues and lipid classes . Perhaps more importantly , the results demonstrate that dietary AA does not alter blood lipids or lipoprotein levels or have obvious adverse health effects at this level and duration of feeding Because human studies concerning the effects of stearic acid on thrombotic tendency are inconsistent , we compared the effects of stearic acid with those of its unsaturated derivatives , oleic acid and linoleic acid . In this r and omized , crossover study , 45 subjects ( 27 women and 18 men ) consumed , in r and om order , 3 experimental diets , each for 5 wk . Diets contained approximately 38 % of energy as fat . Dietary compositions were the same except for 7 % of energy from stearic , oleic , or linoleic acids . At the end of each period , ex vivo and in vitro platelet aggregation , and variables of coagulation , fibrinolysis , and hematology were evaluated . In men , ex vivo platelet aggregation time as measured by filtragometry ( P = 0.036 for diet effects ) was favorably prolonged during consumption of the linoleic acid diet compared with the stearic acid diet ( P = 0.040 ) , but there was no difference with consumption of the oleic acid diet ( P = 0.198 ) . In vitro platelet aggregation induced by collagen and ADP , and variables of coagulation ( factor VII amidolytic activity and concentrations of fibrinogen and prothrombin fragment 1 and 2 ) and fibrinolysis [ plasminogen activator inhibitor ( PAI ) activity and concentrations of tissue plasminogen activator (tPA)/PAI-1 complexes ] did not differ among the 3 diets . The mean platelet volume of the subjects decreased during consumption of the stearic acid diet by 0.32 fL compared with the oleic acid diet ( P < 0.001 ) and by 0.35 fL compared with the linoleic acid diet ( P < 0.001 ) . In conclusion , our results do not suggest that stearic acid is highly thrombogenic compared with oleic and linoleic acids BACKGROUND Dietary alpha-linolenic acid ( ALA ) can be converted to long-chain n-3 polyunsaturated fatty acids ( PUFAs ) in humans and may reproduce some of the beneficial effects of eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) on cardiovascular disease risk factors . OBJECTIVE This study aim ed to compare the effects of increased dietary intakes of ALA and EPA+DHA on a range of atherogenic risk factors . DESIGN This was a placebo-controlled , parallel study involving 150 moderately hyperlipidemic subjects r and omly assigned to 1 of 5 interventions :  0.8 or 1.7 g EPA+DHA/d  , 4.5 or 9.5 g ALA/d , or an n-6 PUFA control for 6 mo . Fatty acids were incorporated into 25 g of fat spread and 3 capsules to be consumed daily . RESULTS The change in fasting or postpr and ial lipid , glucose , or insulin concentrations or in blood pressure was not significantly different after any of the n-3 PUFA interventions compared with the n-6 PUFA control . The mean ( + /- SEM ) change in fasting triacylglycerols after the 1.7-g/d EPA+DHA intervention ( -7.7 + /- 4.99 % ) was significantly ( P < 0.05 ) different from the change after the 9.5-g/d ALA intervention ( 10.9 + /- 4.5 % ) . The ex vivo susceptibility of LDL to oxidation was higher after the 1.7-g/d EPA+DHA intervention than after the control and ALA interventions ( P < 0.05 ) . There was no significant change in plasma alpha-tocopherol concentrations or in whole plasma antioxidant status in any of the groups . CONCLUSION At estimated biologically equivalent intakes , dietary ALA and EPA+DHA have different physiologic effects BACKGROUND Animal studies showed that dietary flaxseed oil [ rich in the n-3 polyunsaturated fatty acid alpha-linolenic acid ( ALA ) ] , evening primrose oil [ rich in the n-6 polyunsaturated fatty acid gamma-linolenic acid ( GLA ) ] , and fish oil [ rich in the long-chain n-3 polyunsaturated fatty acids eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) ] can decrease natural killer ( NK ) cell activity . There have been no studies of the effect on NK cell activity of adding these oils to the diet of humans . OBJECTIVE Our objective was to determine the effect of dietary supplementation with oil blends rich in ALA , GLA , arachidonic acid ( AA ) , DHA , or EPA plus DHA ( fish oil ) on the NK cell activity of human peripheral blood mononuclear cells . DESIGN A r and omized , placebo-controlled , double-blind , parallel study was conducted . Healthy subjects aged 55 - 75 y consumed 9 capsules/d for 12 wk ; the capsules contained placebo oil ( an 80:20 mix of palm and sunflower seed oils ) or blends of placebo oil and oils rich in ALA , GLA , AA , DHA , or EPA plus DHA . Subjects in these groups consumed 2 g ALA , 770 mg GLA , 680 mg AA , 720 mg DHA , or 1 g EPA plus DHA ( 720 mg EPA + 280 mg DHA ) daily , respectively . Total fat intake from the capsules was 4 g/d . RESULTS The fatty acid composition of plasma phospholipids changed significantly in the GLA , AA , DHA , and fish oil groups . NK cell activity was not significantly affected by the placebo , ALA , GLA , AA , or DHA treatment . Fish oil caused a significant reduction ( mean decline : 48 % ) in NK cell activity that was fully reversed by 4 wk after supplementation had ceased . CONCLUSION A moderate amount of EPA but not of other n-6 or n-3 polyunsaturated fatty acids can decrease NK cell activity in healthy subjects To compare the effects of highly purified ethyl ester concentrates of eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) on serum lipids , apolipoproteins , and serum phospholipid fatty acids in humans , we conducted a double-blind , placebo-controlled , parallel design intervention study . Healthy nonsmoking men ( n = 234 ) aged 36 - 56 y were r and omly assigned to dietary supplementation with 3.8 g EPA/d , 3.6 g DHA/d , or 4.0 g corn oil/d ( placebo ) for 7 wk . Serum triacylglycerols decreased 26 % ( P < 0.0001 ) in the DHA group and 21 % ( P = 0.0001 ) in the EPA group compared with the corn oil group . Although not significant , net decreases in serum triacylglycerols were consistently greater in the DHA group across all quartiles of baseline triacylglycerol concentrations . Serum high-density-lipoprotein cholesterol increased 0.06 mmol/L ( P = 0.0002 ) in the DHA group . In the EPA group , serum total cholesterol decreased 0.15 mmol/L ( P = 0.02 ) and apolipoprotein A-I decreased 0.04 g/L ( P = 0.0003 ) . In the DHA group , serum phospholipid DHA increased by 69 % and EPA increased by 29 % , indicating retroconversion of DHA to EPA . In the EPA group , serum phospholipid EPA increased by 297 % whereas DHA decreased by 15 % , suggesting that EPA is not elongated to DHA in humans . The serum phospholipid ratio of n-3 to n-6 fatty acids increased in both groups , whereas the relative changes in n-6 fatty acids suggested possible alterations in liver desaturation activity in the DHA group . We conclude that both DHA and EPA decrease serum triacylglycerols , but have differential effects on lipoprotein and fatty acid metabolism in humans BACKGROUND The fatty acid content and saturation degree of the diet can modulate HDL composition and cholesterol efflux . OBJECTIVE We studied the modifications in plasma lipoprotein particles and serum capacity to stimulate cholesterol efflux induced by different fatty acids . DESIGN Seventeen women and 24 men followed in the same sequence 4 diets containing 35 % of total energy as fat . The saturated fat diet contained 17 % palm oil ; the monounsaturated fat diet , 20.9 % olive oil ; the n-6 polyunsaturated fat diet , 12.5 % sunflower oil ; and the n-3 polyunsaturated fat diet , sunflower oil supplemented with 4 - 4.5 g fish oil/d . Each phase lasted 4 - 5 wk . RESULTS In both sexes , apolipoprotein ( apo ) A-I concentrations were significantly lower with unsaturated fat diets than with the saturated fat diet , but concentrations of lipoproteins containing only apo A-I ( Lp A-I ) were lower only in the men . Concentrations of lipoproteins containing both apo A-I and apo A-II ( Lp A-I : A-II ) were lower with both polyunsaturated fat diets in the women but significantly higher in the men . Lp E concentrations were significantly higher with the 2 polyunsaturated fat diets . Lp E non-B particle concentrations were not modified in the men but were significantly higher in the women in both polyunsaturated fat phases . Lp C-III concentrations were higher with the saturated fat diet only in the men . The serum sample s taken after the n-3 polyunsaturated fat phase were the most efficient for extracting cellular cholesterol in both sexes . CONCLUSIONS The monounsaturated and polyunsaturated fat diets were healthier , producing a better lipid profile . The n-3 polyunsaturated fat diet increased the capacity of serum to promote the efflux of cholesterol from cells in culture The view expressed by Cuthbertson that essential fatty acid needs of human infants have been overestimated is contested . In our view Cuthbertson 's assessment of essential fatty acid requirements of infants is too low because 1 ) consideration of the omega3 fatty acids is omitted ; 2 ) the biological value of long-chain essential fatty acids is wrongly assessed ; and 3 ) the significance of variations in composition of r and om human milk sample s is misunderstood BACKGROUND It is still unknown whether the fatty acid composition of human skeletal muscle lipids is directly influenced by the fat composition of the diet . OBJECTIVE We investigated whether the fatty acid composition of the diet is reflected in the fatty acid profile of skeletal muscle phospholipids and triacylglycerols . DESIGN Thirty-two healthy adults ( 25 men and 7 women ) included in a larger controlled , multicenter dietary study were r and omly assigned to diets containing a high proportion of either saturated fatty acids ( SFAs ) [ total fat , 36 % of energy ; SFAs , 18 % of energy ; monounsaturated fatty acids ( MUFAs ) , 10 % of energy ] or MUFAs ( total fat , 35 % of energy ; SFAs , 9 % of energy ; MUFAs , 19 % of energy ) for 3 mo . Within each diet group , there was a second r and om assignment to supplementation with fish oil capsules [ containing 3.6 g n-3 fatty acids/d ; 2.4 g eicosapentaenoic acid ( 20:5n-3 ) and docosahexaenoic acid ( 22:6n-3 ) ] or placebo . A muscle biopsy sample was taken from the vastus lateralis muscle after the diet period . Parallel analyses of diet and supplementation effects were performed . RESULTS The proportions of myristic ( 14:0 ) , pentadecanoic ( 15:0 ) , heptadecanoic ( 17:0 ) , and palmitoleic ( 16:1n-7 ) acids in the skeletal muscle phospholipids were higher and the proportion of oleic acid ( 18:1n-9 ) was lower in the SFA group than in the MUFA group . The proportion of total n-3 fatty acids in the muscle phospholipids was approximately 2.5 times higher , with a 5 times higher proportion of eicosapentaenoic acid ( 20:5n-3 ) , in subjects supplemented with n-3 fatty acids than in those given placebo . Similar differences were observed in the skeletal muscle triacylglycerols . CONCLUSION The fatty acid composition of skeletal muscle lipids reflects the fatty acid composition of the diet in healthy men and women BACKGROUND Vegetarians have lower platelet and plasma concentrations of n-3 polyunsaturated fatty acids ( PUFAs ) than do omnivores . We recently showed that male vegetarians have higher platelet aggregability than do omnivores . OBJECTIVE We investigated whether male vegetarians ( n = 17 ) who consumed an increased amount of dietary alpha-linolenic acid ( ALA )  showed any changes in their tissue profile of PUFAs , plasma thromboxane concentrations , platelet aggregability , or hemostatic factors . DESIGN During the study , all subjects maintained their habitual vegetarian diets except that a proportion of dietary fat was replaced with vegetable oils and margarines that were provided . Initially , all subjects consumed a low-ALA diet ( containing safflower oil and safflower oil-based margarine ) for 14 d ; they then consumed either a moderate-ALA diet ( containing canola oil and canola oil-based margarine ) or a high-ALA diet ( containing linseed oil and linseed oil-based margarine ) for 28 d. Blood sample s were collected at day 0 ( baseline ) , day 14 , and day 42 . RESULTS Eicosapentaenoic acid , docosapentaenoic acid , total n-3 PUFAs , and the ratio of n-3 to n-6 PUFAs were significantly increased ( P < 0.05 ) , whereas the ratio of arachidonic acid to eicosapentaenoic acid was decreased ( P < 0.05 ) , in platelet phospholipids , plasma phospholipids , and triacylglycerols after either the moderate-ALA or high-ALA diet compared with the low-ALA diet . No significant differences were observed in thrombotic risk factors . CONCLUSION ALA from vegetable oils ( canola and linseed ) has a beneficial effect on n-3 PUFA concentrations of platelet phospholipids and plasma lipids in vegetarian males The purpose of this double-blind study was to investigate the influence of dietary supplementation with an algae source of docosahexaenoic acid [ DHA ; 22:6(n-3 ) ] , devoid of any eicosapentaenoic acid [ EPA ; 20:5(n-3 ) ] , on serum/platelet DHA status , the estimated retroconversion of DHA to EPA , and risk factors for heart disease in vegetarian subjects . Healthy vegetarians ( 12 male , 12 female ) consumed nine capsules daily of either DHA ( 1.62 g/d ) or corn oil for 6 wk . Consumption of DHA capsules increased DHA levels in serum phospholipid by 246 % ( from 2.4 to 8.3 g/100 g fatty acids ) and in platelet phospholipid by 225 % ( from 1.2 to 3.9 g/100 g fatty acids ) . EPA levels increased in serum phospholipid by 117 % ( from 0.57 to 1.3 g/100 g fatty acids ) and in platelet phospholipid by 176 % ( 0.21 to 0.58 g/100 g fatty acids ) via metabolic retroconversion ; the estimated extent of DHA retroconversion to EPA was 11.3 and 12.0 % , based on the serum and platelet analyses , respectively . Arachidonic acid [ AA ; 20:4(n-6 ) ] levels in serum and platelet phospholipids decreased moderately during the trial period ( DHA group ) as did both docosapentaenoic acids [ 22:5(n-6 ) and 22:5(n-3 ) ] . Although no significant changes were found in the total and LDL-cholesterol levels with DHA supplementation , the total cholesterol : HDL-cholesterol ratio showed a moderate decrease over time as did the LDL-cholesterol : HDL-cholesterol ratio and serum triglyceride concentrations . DHA supplementation did not alter the various thrombogenic factors measured . In conclusion , DHA supplementation markedly enhanced the DHA status ( of serum and platelets ) , provided for the formation of substantial EPA , and lowered the total and LDL-cholesterol : HDL-cholesterol ratios BACKGROUND A variety of soybean oils were developed with improved oxidative stability and functional characteristics for use as alternatives to partially hydrogenated fat . OBJECTIVE The objective was to assess the effect of selectively bred and genetically modified soybean oils with altered fatty acid profiles , relative to common soybean and partially hydrogenated soybean oils , on cardiovascular disease risk factors . DESIGN Thirty subjects ( 16 women and 14 men ) aged > 50 y with LDL-cholesterol concentrations > 130 mg/dL at screening consumed 5 experimental diets in r and om order for 35 d each . Diets contained the same foods and provided 30 % of energy as fat , of which two-thirds was either soybean oil ( SO ) , low-saturated fatty acid soybean oil ( LoSFA-SO ) , high-oleic acid soybean oil ( HiOleic-SO ) , low-alpha-linolenic acid soybean oil ( LoALA-SO ) , or partially hydrogenated soybean oil ( Hydrog-SO ) . RESULTS Plasma phospholipid patterns reflected the predominant fat in the diet . LDL-cholesterol concentrations were 3.66 + /- 0.67(b ) , 3.53 + /- 0.77(b ) , 3.70 + /- 0.66(b ) , 3.71 + /- 0.64(a , b ) , and 3.92 + /- 0.70(a ) mol/L ; HDL-cholesterol concentrations were 1.32 + /- 0.32(a , b ) , 1.32 + /- 0.35(b ) , 1.36 + /- 0.33(a ) , 1.32 + /- 0.33(b ) , and 1.32 + /- 0.32(a , b ) mol/L for the SO , LoSFA-SO , HiOleic-SO , LoALA-SO , and Hydrog-SO diets , respectively ( values with different superscript letters are significantly different , P < 0.05 ) . No significant effects were observed on VLDL-cholesterol , triacylglycerol , lipoprotein(a ) , and C-reactive protein concentrations or on ratios of LDL cholesterol to apolipoprotein B ( apo B ) and HDL cholesterol to apo A-I. Total cholesterol : HDL cholesterol was lower after subjects consumed the unhydrogenated soybean oils than after they consumed the Hydrog-SO diet . CONCLUSIONS All varieties of soybean oils result ed in more favorable lipoprotein profiles than did the partially hydrogenated form . These soybean oils may provide a viable option for reformulation of products to reduce the content of trans fatty acids BACKGROUND The utility of fatty acids ( FAs ) as biomarkers of total fat intake is unknown . OBJECTIVE We compared FA changes in red cells ( RCs ) , plasma phospholipids ( PLs ) , and cholesterol esters ( CEs ) in response to a low-fat diet ( LFD ) and a moderate-fat diet ( MFD ) and assessed whether individual or combination of FAs predict LFD . DESIGN Postmenopausal women ( n = 66 ) were r and omly assigned to receive an LFD ( 17 % of energy from fat ) or an MFD ( 34 % of energy from fat ) for 6 wk . All foods were provided . FAs in diets and blood were determined by gas-liquid chromatography .  FA changes between baseline and end of study were compared across diets by using t tests . FA predictors of an LFD were selected by logistic regression . RESULTS Many FAs in RCs , PLs , and CEs responded differently to the 2 diets . Changes from baseline with an LFD for palmitic acid ( 16:0 ) ( 3 - 11 % increase ) , behenic ( 22:0 ) and lignoceric ( 24:0 ) acids ( 3 - 20 % decrease , in RCs and PLs only ) , cis-monounsaturated FA ( MUFA ) ( 25 - 35 % increase ) , linoleic acid ( 18:2n-6 ) ( 11 - 13 % decrease ) , trans octadecanoic acids ( trans 18:1 ) ( 7 - 20 % decrease ) , and n-6 highly unsaturated FA ( HUFA ) ( 2 - 8 % increase ) were significantly different from changes with an MFD . Individually , 18:2n-6 and trans 18:1 were strong predictors of an LFD [ receiver operating characteristic ( ROC ) curves : 0.92 - 0.80 ) . A logistic regression model with trans 18:1 , 18:2n-6 , and vaccenic acid ( 18:1n-7 ) predicted an LFD with high specificity and sensitivity ( ROC curves : 0.99 ) . CONCLUSIONS Saturated FA , cisMUFA , n-6 HUFA , and exogenous FAs greatly differed in their response to the LFD and MFD . Parallel responses were observed in RCs , PLs , and CEs . A model with a combination of FAs almost perfectly differentiated the consumption of 34 % fat from that of 17 % fat High linoleic acid ( LA ) intakes have been suggested to reduce alpha-linolenic acid [ ALA , 18:3(n-3 ) ] metabolism to eicosapentaenoic acid [ EPA , 20:5(n-3 ) ] and docosahexaenoic acid [ DHA , 22:6(n-3 ) ] , and favor high arachidonic acid [ ARA , 20:4(n-6 ) ] . We used a r and omized cross-over study with men ( n = 22 ) to compare the effect of replacing vegetable oils high in LA with oils low in LA in foods , while maintaining constant ALA , for 4 wk each , on plasma ( n-3 ) fatty acids . Nonvegetable sources of fat , except fish and seafoods , were unrestricted . We determined plasma phospholipid fatty acids at wk 0 , 2 , 4 , 6 , and 8 , and triglycerides , cholesterol , serum CRP , and IL-6 , and platelet aggregation at wk 0 , 4 , and 8 .  LA and ALA intakes were 3.8 + /- 0.12 % and 1.0 + /- 0.05 % , and 10.5 + /- 0.53 % and 1.1 + /- 0.06 % energy with LA : ALA ratios of 4:0 and 10:1 during the low and high LA diets , respectively . The plasma phospholipid LA was higher and EPA was lower during the high than during the low LA diet period ( P < 0.001 ) , but DHA declined over the 8-wk period ( r = -0.425 , P < 0.001 ) . The plasma phospholipid ARA : EPA ratios were ( mean + /- SEM ) 20.7 + /- 1.52 and 12.9 + /- 1.01 after 4 wk consuming the high or low LA diets , respectively ( P < 0.001 ) ; LA was inversely associated with EPA ( r = -0.729 , P < 0.001 ) but positively associated with ARA : EPA ( r = 0.432 , P < 0.001 ) . LA intake did not influence ALA , ARA , DPA , DHA , or total , LDL or HDL cholesterol , CRP or IL-6 , or platelet aggregation . In conclusion , high LA intakes decrease plasma phospholipid EPA and increase the ARA : EPA ratio , but do not favor higher ARA Thirty healthy male volunteers were r and omly allocated into two dietary treatment groups . The  flaxseed group ( n = 15 ) maintained a diet high in alpha-linolenic acid ( alpha-LA ; 18:3n-3 ) and low in linoleic acid ( LA ; 18:2n-6 ) by using a flaxseed oil and spread that are high in alpha-LA . The  control group ( n = 15 ) maintained a diet high in LA and low in alpha-LA , typifying a Western diet . Both groups maintained their diets for 4 wk , followed by another 4-wk period in which they supplemented the diets with fish oil [ 1.62 g eicosapentaenoic acid ( EPA , 20:5n-3 ) daily and 1.08 g docosahexaenoic acid ( DHA , 22:6n-3 ) daily ] in a triglyceride form . The flaxseed oil-containing diet result ed in significant increases in alpha-LA concentrations in the plasma phospholipid , cholesteryl ester , and triglyceride fractions ( eightfold increase ) and neutrophil phospholipids ( 50 % increase ) . EPA concentrations increased by 2.5-fold in the plasma lipid fractions and neutrophil phospholipids . After fish-oil supplementation  EPA concentrations increased in parallel in both dietary groups , remaining higher in the flaxseed group for both the plasma lipid fractions and neutrophil phospholipids . The results indicate that alpha-LA-rich vegetable oils can be used in a domestic setting ( in conjunction with a background diet low in LA ) to elevate EPA in tissues to concentrations comparable with those associated with fish-oil supplementation BACKGROUND Supplementation of the diet with fish oil , which is rich in the long-chain n-3 polyunsaturated fatty acids eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) , is reported to decrease several markers of immune function . However , whether EPA , DHA , or a combination of the 2 exerts these immunomodulatory effects is unclear . OBJECTIVE The objective of the study was to determine the effects of supplementation with an EPA-rich or DHA-rich oil on a range of immune outcomes representing key functions of human neutrophils , monocytes , and lymphocytes in healthy humans . DESIGN In a placebo-controlled , double-blind , parallel study , 42 healthy subjects were r and omly allocated to receive supplementation with either placebo ( olive oil ) , EPA ( 4.7 g/d ) , or DHA ( 4.9 g/d ) for 4 wk . Blood sample s were taken before and after supplementation . RESULTS The fatty acid composition of plasma phospholipids and neutrophils was dramatically altered by supplementation with EPA or DHA , and the effects of EPA differed notably from those of DHA . DHA supplementation decreased T lymphocyte activation , as assessed by expression of CD69 , whereas EPA supplementation had no significant effect . Neither the EPA-rich oil nor the DHA-rich oil had any significant effect on monocyte or neutrophil phagocytosis or on cytokine production or adhesion molecule expression by peripheral blood mononuclear cells . CONCLUSIONS Supplementation with DHA , but not with EPA , suppresses T lymphocyte activation , as assessed by expression of CD69 . EPA alone does not , therefore , influence CD69 expression . No other marker of immune function assessed in this study was significantly affected by either EPA or DHA To underst and the in vivo metabolism of dietary gamma-linolenic acid ( GLA ) , we supplemented the diets of 29 volunteers with GLA in doses of 1.5 - 6.0 g/d . Twenty-four subjects ate controlled eucaloric diets consisting of 25 % fat ; the remaining subjects maintained their typical Western diets .  GLA and dihomo-gamma-linolenic acid ( DGLA ) increased in serum lipids of subjects supplemented with 3.0 and 6.0 g/d ; serum arachidonic acid increased in all subjects . GLA supplementation with 3.0 and 6.0 g/d also result ed in an enrichment of DGLA in neutrophil phospholipids but no change in GLA or AA levels . Before supplementation , DGLA was associated primarily with phosphatidylethanolamine ( PE ) of neutrophil glycerolipids , and DGLA increased significantly in PE and neutral lipids after GLA supplementation . Extending the supplementation to 12 wk did not consistently change the magnitude of increase in either serum or neutrophil lipids in subjects receiving 3.0 g/d . After GLA supplementation , A23187-stimulated neutrophils released significantly more DGLA , but AA release did not change . Neutrophils obtained from subjects after 3 wk of supplementation with 3.0 g/d GLA synthesized less leukotriene B4 ( P < 0.05 ) and platelet-activating factor . Together , these data reveal that DGLA , the elongase product of GLA , but not AA accumulates in neutrophil glycerolipids after GLA supplementation . The increase in DGLA relative to AA within inflammatory cells such as the neutrophil may attenuate the bio synthesis of AA metabolites and may represent a mechanism by which dietary GLA exerts an anti-inflammatory effect Plasma fatty acid composition reflects dietary fatty acids . Whether the total fat content of the diet alters the fatty acid composition of plasma phospholipid , cholesteryl ester , triacylglycerol and free fatty acids is unknown . To evaluate the effects of low versus high fat diets on plasma fatty acids , a 12-wk , r and omized , crossover , controlled feeding trial was conducted in healthy men and women with isoenergic low fat ( 20 % energy ) and high fat ( 45 % energy ) diets containing constant proportions of fatty acids . Ten subjects consumed one  experimental diet  for 28 d , their usual diet for 4 wk and the alternate experimental diet for 28 d.  Endpoint measures of plasma fatty acids were determined at the end of each experimental period . The effects of the two diets were compared within subjects by analysis of variance . Plasma fatty acids ( % ) varied in response to total dietary fat with significantly greater total polyunsaturated fat , ( n-6 ) and 18:2(n-6 ) levels in phospholipids and cholesteryl esters after high fat dietary consumption . The low fat diet was associated with significantly greater total ( n-3 ) fatty acids , 20:5(n-3 ) and 22:6(n-3 ) levels in plasma phospholipid fatty acids and cholesteryl esters . Consumption of a low fat diet alters fatty acid patterns in a manner similar to that observed with feeding of ( n-3 ) long-chain fatty acids . This change is likely related to decreased competition for the enzymes of elongation and desaturation , with reduced total intake of 18:2(n-6 ) favoring elongation and desaturation of available ( n-3 ) fatty acids OBJECTIVE To examine the ability of alpha-linolenic acid ( ALA ) in low erucic acid rapeseed oil ( RO ) to compensate for the effects of a restriction in fish intake on plasma fatty acid composition . DESIGN AND SUBJECTS Two times 6 weeks ' r and omized dietary intervention was used with blind crossover design in 40 healthy unconfined women and men ( age 20 - 46y ) . INTERVENTIONS Subjects were assigned to two fish restricted diets , namely RO diet and Trisun-sunflower oil ( TSO ) diet , with similar proportions of saturated : monounsaturated : polyunsaturated fatty acids ( 11.5:17.5:8.5 % of total energy , En% ) , but differing in their ALA content ( 2.2 and 0.3 En% ) and n-6 : n-3-ratio ( 3 : 1 and 23 : 1 , respectively ) . The fatty acid compositions of plasma triglycerides ( TG ) , cholesterol esters ( CE ) , and phospholipids ( PL ) were analyzed by gas chromatography . Dietary intake was evaluated based on 3- to 7-day food records . RESULTS The proportion of TG and CE ALA decreased on the TSO diet ( from 1.6 % to 0.9 % and from 0.9 % to 0.4 % , respectively , P < 0.001 ) and increased on the RO diet ( from 1.7 % to 3.4 % and from 0.9 % to 1.3 % , respectively , P < 0.001 ) compared to the baseline level . The proportion of eicosapentaenoic acid ( EPA ) in all three plasma fractions decreased on the TSO diet but not on the RO diet . The proportions of docosa-hexaenoic acid ( DHA ) decreased on both experimental diets and there was no difference in CE DHA between the diets . PL docosa-pentaenoic acid ( DPA ) and PL DHA remained at a higher level on the RO diet compared to the TSO diet ( P < 0.001 and P < 0.05 , respectively ) . CONCLUSIONS ALA is metabolized to EPA in humans to a significant extent . The degree to which rapeseed oil ( ca 50g/day ) affects the proportion of EPA resembled the effect of a weekly portion ( 50 - 100 g ) of fatty fish depending on the fat content of the fish The time-resolved fluorescence emission and decay of fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene ( DPH ) was used to characterize equilibrium and dynamic bilayer structural properties of symmetrically substituted phosphatidylcholines ( PCs ) with acyl chains containing no , one , four , or six double bonds and mixed-chain phosphatidylcholines with a saturated sn-1 chain and one , four , or six double bonds in the sn-2 chain . Both the Brownian rotational diffusion ( BRD ) model and the wobble-in-cone model were fit to all differential polarization data , and the descriptions of the data provided by the BRD model were found to be statistically superior . Global analysis of differential polarization data revealed two statistically equivalent solutions . The solution corresponding to a bimodal orientational distribution function , f(theta ) , was selected based on the effects of temperature on f(theta ) and previous measurements on fixed , oriented bilayers . The overall equilibrium acyl chain order in these bilayers was analyzed by comparing the orientational probability distribution for DPH , f(theta ) sin theta , with a r and om orientational distribution . Orientational order decreased and probe dynamics increased in mixed-chain species as the unsaturation of the sn-2 chain was increased . The degree of orientational order dropped dramatically in the dipolyunsaturated species compared with the mixed-chain phosphatidylcholines , which contained a polyunsaturated sn-2 chain . In terms of both orientational order and probe dynamics , the differences between the highly polyunsaturated species and the monounsaturated species were much greater than the differences between the monounsaturated species and a disaturated PC BACKGROUND AND METHODS Experiments in animals and two epidemiologic studies in humans suggest that aspirin and other nonsteroidal antiinflammatory drugs ( NSAIDs ) may be protective against colon cancer . We tested this hypothesis in a prospect i ve mortality study of 662,424 adults who provided information in 1982 on the frequency and duration of their aspirin use .  Death rates from colon cancer were measured through 1988 . The possible influence of other risk factors for colon cancer was examined in multivariate analyses for 598 case patients and 3058 matched control subjects drawn from the cohort . RESULTS Death rates from colon cancer decreased with more frequent aspirin use in both men and women . The relative risk among persons who used aspirin 16 or more times per month for at least one year was 0.60 in men ( 95 percent confidence interval , 0.40 to 0.89 ) and 0.58 in women ( 95 percent confidence interval , 0.37 to 0.90 ) . The risk estimates were unaffected when we excluded persons who reported at entry into the study that they had cancer , heart disease , stroke , or another condition that might influence both their aspirin use and their mortality . Adjustment for dietary factors , obesity , physical activity , and family history did not alter the findings significantly . No association was found between the use of acetaminophen and the risk of colon cancer . CONCLUSIONS Regular aspirin use at low doses may reduce the risk of fatal colon cancer . Whether this is due to a direct effect of aspirin , perhaps mediated by the inhibition of prostagl and in synthesis , or to other factors indirectly associated with aspirin use is unclear Ethyl arachidonate was administered orally to 4 healthy male volunteers in a dose of 6 gm daily for a 2 to 3 wk period after a 1O‐day control period . The increased intake of this precursor of the dienoic prostagl and ins result ed in significant increases in the relative and absolute amount of arachidonate in plasma triglycerides , phospholipids , and cholesteryl esters . Similar changes in lipid composition were noted in platelets . The excretion of 7 α‐hydroxy‐5 , 11‐diketotetranorprostane‐1 , 16‐dioic acid , the major urinary metabolite of E prostagl and ins in man , was increased by an average of 47 % in 3 of the 4 volunteers .  Platelet reactivity was assessed by determining the threshold concentration of adenosine diphosphate ( ADP ) necessary to induce secondary , irreversible aggregation of platelet‐rich plasma . This threshold concentration dropped significantly in all volunteers ( 10 % to 60 % of control values ) . It is concluded that the bio synthesis and function of prostagl and ins can be augmented in man by oral administration of an esterified precursor fatty acid In the present study , we examined the effects of arachidonic acid ( ARA ) on age-related event-related potential ( ERP ) changes in 25 healthy elderly men . This study was performed using a double-blind crossover design . The subjects were administered 600 mg/day of ARA-enriched triglyceride ( SUNTGA40S ; containing 240 mg ARA ) in capsules or the same amount of olive oil in capsules as an inactive placebo for 1 month . ERPs were measured before capsule administration and after 1 month of administration , and P300 latency and amplitude were also measured . In subjects administered 240 mg/day ARA , P300 latency was significantly shorter , and P300 amplitude was significantly higher than in those administered olive oil capsules , and they exhibited a significant increase in ARA content in serum phospholipids . These findings suggest that supplementation of ARA can improve cognitive function in healthy elderly men Eicosanoids are oxidative derivatives of arachidonic acid . When produced in excessive amounts , many are proinflammatory and /or prothrombotic agents . N-3 polyunsaturated fatty acids ( PUFA ) have been used to attenuate tissue arachidonic acid ( AA , 20:4 n-6 ) levels and thus modulate eicosanoid production . However , there is growing evidence that dietary arachidonic acid may also be able to modulate eicosanoid formation by enriching tissue phospholipids with AA . Therefore , the effects of dietary AA and n-3 PUFA are in diametric opposition . This study investigates the antithetic relationship of dietary AA and eicosapentaenoic acid ( EPA , 20:5 n-3 ) on fatty acid composition of hepatic phospholipids and eicosanoid production in vivo . Forty-nine CD-1 male mice were r and omly divided into four dietary groups . Identical diets were supplemented with ethyl esters ( 1.5 % w/w ) of the following fatty acids : oleic acid ( OA , 18:1 n-9 ) , AA , EPA or AA+EPA . After 4 weeks on diet , peritoneal cells were stimulated in vivo with opsonized zymosan and the peritoneal exu date s were analyzed for eicosanoid production ( PGE2 , 6-keto-PGF1 alpha , TXB2 , LTB4 , LTE4 , and LTE5 ) . Hepatic phospholipids were enriched with AA when AA was included in the diet , and EPA was enriched at the expense of AA when EPA was added to the diet . However , when AA was added to the diet containing equivalent amounts of EPA ( AA+EPA ) , any effect EPA had on modulating hepatic phospholipid fatty acid composition was almost completely eliminated . Similar effects were observed with eicosanoid production . The pooled eicosanoid production in the AA group was 41 % and 300 % higher compared to the OA ( control ) and EPA groups , respectively . ( ABSTRACT TRUNCATED AT 250 WORDS BACKGROUND Several studies have reported that dietary fish oil ( FO ) supplementation alters cytokine production and other functional activities of peripheral blood mononuclear cells ( P BMC ) . However , few of these studies have been placebo controlled and few have related the functional changes to alterations in P BMC fatty acid composition PATIENTS AND METHODS Healthy subjects supplemented their diets with 9 g day-1 of encapsulated placebo oil ( 3 : 1 mix of coconut and soybean oils ) , olive oil ( OO ) , safflower oil ( SO ) , evening primrose oil ( EPO ) or FO [ providing 2.1 g eicosapentaenoic acid ( EPA ) plus 1.1 g docosahexaenoic acid ( DHA ) per day ] for 12 weeks ; the capsules also provided 205 mg alpha-tocopherol per day . Blood was sample d at 4-weekly intervals and plasma and P BMC prepared . Plasma phospholipid and P BMC fatty acid composition , plasma alpha-tocopherol and thiobarbituric acid-reactive substance concentrations , plasma total antioxidant capacity , the proportions of different P BMC subsets , the proportions of P BMC expressing the adhesion molecules CD2 , CD11b and CD54 , and P BMC functions ( lymphocyte proliferation , natural killer cell activity , cytokine production ) were measured . All measurements were repeated after a ' washout ' period of 8 weeks . RESULTS The placebo , OO and SO capsules had no effect on plasma phospholipid or P BMC fatty acid composition . The proportion of dihomo-gamma-linolenic acid in plasma phospholipids was elevated in subjects taking EPO and was decreased in subjects taking FO . There was no appearance of gamma-linolenic acid in the plasma phospholipids or P BMC in subjects taking EPO . There was a marked increase in the proportion of EPA in the plasma phospholipids ( 10-fold ) and P BMC ( four-fold ) of subjects taking FO supplements ; this increase was maximal after 4 weeks of supplementation . There was an increase in the proportion of DHA in plasma phospholipids and P BMC , and an approximately 20 % decrease in the proportion of arachidonic acid in plasma phospholipids and P BMC , during FO supplementation . Plasma concentrations of alpha-tocopherol were significantly elevated during supplementation in all subjects and returned to baseline values after the washout period . There were no effects of supplementation with any of the capsules on total plasma antioxidant activity or plasma thiobarbituric acid-reactive substances or on the proportion of different P BMC subsets , on the proportion of P BMC expressing adhesion molecules , on natural killer cell activity , on the proliferation of mitogen-stimulated whole blood cultures or P BMC , or on the ex vivo production of a range of cytokines by whole blood cultures or P BMC cultures stimulated by either concanavalin A or lipopolysaccharide . CONCLUSION Supplementation of the diet with 3.2 g EPA plus DHA per day markedly alters plasma phospholipid and P BMC fatty acid compositions . The lack of effect of FO upon P BMC functions may relate to the level of alpha-tocopherol included in the supplements Essential fatty acid ( EFA ) deficiency has become a clinical problem since the advent of fat-free total parenteral nutrition ( TPN ) . The following study was done to determine the minimum fat requirements for patients receiving continuous TPN solution . Seventy-seven patients who had 97 courses of TPN of at least 14 days duration were prospect ively studied . The following fat supplementation was given : a ) none , b ) 10 % soybean oil emulsion intravenously at fixed dosage , c ) fat from an oral diet , or d ) intravenous and oral fat . No patient was EFA deficient before the onset of TPN . EFA deficiency was prevented when at least 3.2 % of total calories were given as intravenous fat or at least 15 % as oral fat . Lesser amounts of fat decreased the rate of EFA deficiency development but did not prevent it from occurring . The 7.7 g/day of linoleic acid provided in 1000 ml per week of 10 % soybean oil emulsion provides adequate fat to prevent EFA deficiency It has shown recently that Evening Primrose Oil ( Efamol ) produces a significant clinical improvement in atopic eczema .  Efamol contains gamma-linolenic acid which is a precursor to PGE1 a more consistent bronchodilator than PGE2 . We have conducted a double blind placebo controlled study in atopic asthmatics given Efamol  for an eight week period looking at the control of asthma , including histamine challenge tests . We have found no effect on the asthma or challenge tests although Efamol produced an alteration in fatty acid profile . The patients showed an abnormal fatty acid profile . We speculate that such fatty acid abnormalities could be important in the aetiology of asthma European diets provide a suboptimal intake of eicosapentaenoic ( 20:5n3 ) and docosahexaenoic ( 22:6n3 ) acids , which are derived mainly from fish oils . The present study indicates that black currant seed oil , which contains 14.5 % alpha-linolenic ( 18:3n3 ) , 12.6 % gamma-linolenic ( 18:3n6 ) , 47.5 % linoleic ( 18:2n6 ) and 2.7 % stearidonic ( 18:4n3 ) acids , could potentially serve as alternative to fish oil as a n3 fatty acid source . Fifteen healthy females participated in a r and omized , double-blind , crossover study including two 4-week periods with either 3 g/day of black currant seed oil or 2.8 g/day of fish oil separated by a 4-week washout period . The results show that black currant seed oil supplementation increased the proportion of 18:3n6 in triacylglycerols ( TAG ) and cholesteryl esters ( CE ) , and that of dihomo-gamma-linolenic ( 20:3n6 ) in TAGs , CEs and glycerophospholipids ( GPL ) ( P<.05 ) . Proportion of 18:3n6 was higher ( P<.05 ) after black currant seed oil than after fish oil in TAGs and CEs , and that of 20:3n6 in TAGs , CEs and GPLs . Black currant seed oil supplementation caused only minor changes in the proportions of 20:5n3 or 22:6n3 . Serum levels of LDL cholesterol were lower ( P<.05 ) after black currant seed oil compared to fish oil .  Plasma glucose concentration decreased during the fish oil supplementation ( P<.05 ) Certain dietary polyunsaturated fatty acids , gamma linolenic ( 18:3n-6 ) and eicosapentaenoic ( 20:5n-3 ) acid , attenuate  cardiovascular reactivity  to stress in rats . To study their effects on cardiovascular reactivity to acute stress in man , 30 men were r and omly assigned to one of three groups and given 28 day supplements of borage oil ( containing 18:3n-6 ) , fish oil ( containing 20:5n-3 ) , or olive oil ( placebo ) .  Reactivity to the Stroop colour-word conflict test was assessed prior to and following treatment . Borage oil alone attenuated blood pressure and heart rate responses to stress , increased skin temperature , and improved task performance . These data suggest that diet may be used to alter  stress reactivity  in man Fish oil supplementation during pregnancy not only improves maternal and neonatal DHA status , but often reduces gamma-linolenic acid ( GLA ) , dihomo-GLA ( DGLA ) , and arachidonic acid ( ARA ) levels also , which may compromise foetal and infant development . The present study investigated the effects of a fish oil/evening primrose oil ( FSO/EPO ) blend ( 456 mg DHA/d and 353 mg GLA/d ) compared to a placebo ( mixture of habitual dietary fatty acids ) on the plasma fatty acid ( FA ) composition in two groups of twenty non-pregnant women using a r and omised , double-blind , placebo-controlled parallel design . FA were quantified in plasma total lipids , phospholipids , cholesterol esters , and TAG at weeks 0 , 4 , 6 and 8 . After 8 weeks of intervention , percentage changes from baseline values of plasma total lipid FA were significantly different between FSO/EPO and placebo for GLA ( + 49.9 % v. + 2.1 % , means ) , DGLA ( + 13.8 % v. + 0.7 % ) and DHA ( + 59.6 % v. + 5.5 % ) , while there was no significant difference for ARA ( - 2.2 % v. - 5.9 % ) . FA changes were largely comparable between plasma lipid fractions . In both groups three subjects reported mild adverse effects . As compared with placebo , FSO/EPO supplementation did not result in any physiologically relevant changes of safety parameters ( blood cell count , liver enzymes ) . In women of childbearing age the tested FSO/EPO blend was well tolerated and appears safe . It increases plasma GLA , DGLA , and DHA levels without impairing ARA status . These data provide a basis for testing this FSO/EPO blend in pregnant women for its effects on maternal and neonatal FA status and infant development This study set out to identify whether stearidonic acid ( 18:4n-3 ; STA ) can be used to increase the eicosapentaenoic acid ( 20:5n-3 ; EPA ) content of plasma lipids and cells in humans and to underst and more about the effects of increased consumption of gamma-linolenic acid ( 18:3n-3 ; GLA ) , STA and EPA in humans . Healthy young males were r and omised to consume one of seven oil blends for a period of 12 weeks ( 9 g oil/day ) ( n = 8 - 12 subjects/group ) . Palm oil , sunflower oil , an EPA-rich oil , borage oil ( rich in GLA ) , and Echium oil ( rich in STA ) were blended in various combinations to generate a placebo oil and oils providing approximately 2 g GLA + STA + EPA per day , but in different combinations . Blood was collected at 0 , 4 , 8 and 12 weeks and the fatty acid compositions of plasma triacylglycerols , cholesteryl esters and phospholipids and of peripheral blood mononuclear cells ( P BMC s ) determined . Significant effects were observed with each lipid fraction . Neither STA nor its derivative 20:4n-3 appeared in any of the lipid fractions studied when STA ( up to 1g/day ) was consumed . However , STA ( 1g/day ) , in combination with GLA ( 0.9 g/day ) , increased the proportion of EPA in some lipid fractions , suggesting that STA-rich plant oils may offer a novel means of increasing EPA status . Furthermore , this combination tended to increase the dihomo-gamma-linolenic acid ( 20:3n-6 ; DGLA ) content of P BMC s , without an increase in arachidonic acid ( AA ) ( 20:4n-6 ) content . EPA consumption increased the EPA content of all lipid fractions studied . Consumption of GLA ( 2g/day ) , in the absence of STA or EPA , increased DGLA content with a tendency to increase AA content in some fractions . This effect was prevented by inclusion of EPA in combination with GLA . Thus , this study indicates that STA may be used as a precursor to increase the EPA content of human lipids and that combinations of GLA , STA and EPA can be used to manipulate the fatty acid compositions of lipid pools in subtle ways . Such effects may offer new strategies for manipulation of cell composition in order to influence cellular responses and functions in desirable ways A small-scale preliminary cross-over study was conducted to investigate the effects of supercritical CO(2)-extracted sea buckthorn berry oil ( SBO ) on some  risk factors  of  cardiovascular disease .  Special features of the oil are high proportions of palmitic ( 16:0 ) , oleic ( 18:1n-9 ) , palmitoleic ( 16:1n-7 ) , linoleic ( 18:2n-6 ) , and alpha-linolenic ( 18:3n-3 ) acids as well as vitamin E , carotenoids , and sterols . Twelve healthy normolipidemic men were recruited and each volunteer consumed SBO and fractionated coconut oil ( control ) 5 g per day for a period of 4 weeks in a r and om order ( wash-out 4 - 8 weeks ) . Phospholipid fatty acids , plasma lipids , and glucose were unaffected by SBO supplementation . Instead , a clear decrease in the rate of adenosine-5'-diphosphate-induced platelet aggregation and maximum aggregation were found . This suggested the beneficial effects of SBO on blood clotting , but further studies on the dose-response effects are needed to assess the practical use of SBO supplements
Background Linoleic acid , with a DRI of 12 - 17 g/d , is the most highly consumed polyunsaturated fatty acid in the Western diet and is found in virtually all commonly consumed foods .
The concern with dietary linoleic acid , being the metabolic precursor of arachidonic acid , is its consumption may enrich tissues with arachidonic acid and contribute to chronic and overproduction of bioactive eicosanoids .
However , no systematic review of human trials regarding linoleic acid consumption and subsequent changes in tissue levels of arachidonic acid has been undertaken .
Objective In this study , we review ed the human literature that reported changes in dietary linoleic acid and its subsequent impact on changing tissue arachidonic acid in erythrocytes and plasma/serum phospholipids .