EPA

Common Name: EPA

Clinical Name: Eicosapentaenoic acid

Summary

EPA

chemical name: Eicosapentaenoic acid.

overview of interactions:
• nutrient affecting drug performance and toxicity: Chemotherapy

• EPA and DHA (Omega-3 Fish Oil) affecting drug toxicity: Cyclosporine

chemistry/function: Eicosapentaenoic acid is a polyunsaturated omega-3 fatty acid.

dietary sources: The richest dietary sources of EPA (and DHA) are cold-water fish, such as mackerel, salmon, herring, sardines, black cod, anchovies, and albacore tuna. Supplemental sources of fish oil typically contain 18% EPA. Adequate levels of DHA are difficult to obtain from a vegetarian diet.

known or potential therapeutic uses: Angina, asthma, Crohn’s disease, chronic kidney disease, diabetes mellitus, eczema, elevated triglycerides, hypertension, multiple sclerosis, osteoarthritis, psoriasis, Raynaud’s disease, rheumatoid arthritis, schizophrenia, SLE (lupus), ulcerative colitis. Research has also shown potential benefits in the treatment of chronic obstructive pulmonary disease (COPD) due to smoking.

mechanism: EPA modulates clotting and has a significant anti-inflammatory effect through its impact on prostaglandin metabolism.

maintenance dose: No maintenance dose has been established. Many physicians experienced in nutritional therapy suggest 100-200 mg per day.

therapeutic dose: Most research has been done with EPA at levels of 3 grams per day, usually in combination with DHA.
Note: It is usually advisable to take vitamin E with EPA to protect it from oxidative damage.

side effects: Digestive upset is possible for some individuals at higher doses. Weight gain and elevations in blood sugar levels have been reported. Increased frequency of epistaxis (nose bleeds) has been observed in some individuals.

toxicity: No toxicities have been reported or suspected as being associated with EPA. Some fish oil-based supplements may contain mercury or other toxins in concentrated forms.

contraindications: Diabetes due to impairment of glucose tolerance, though regular exercise (one half hour, three times per week) has been shown to prevent that outcome for many individuals.



Interactions

nutrient affecting drug performance and toxicity: Chemotherapy

• mechanism: Dietary intake of essential fatty acids (EFA) may play a role in both the prevention and treatment of cancer. For example, epidemiological studies have demonstrated that men whose dietary intake is high in omega-3 fatty acid (FA) composition have a lower incidence of prostate cancer.

• research: Several key oils, particularly the fish oils DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), have demonstrated beneficial effects for patients receiving chemotherapy for cancer. Most dramatically researchers have found that they can significantly slow the rate of weight loss associated with most forms of chemotherapy and stabilize adipose tissue and muscle mass. Wigmore reported findings of a significant positive effect of polyunsaturated fatty acids on the progress of cachexia in patients with pancreatic cancer.

Furthermore essential fatty acids have been shown to be cytotoxic to a variety of tumor cells in vitro. Iigo and other researchers, especially among those from Japan, have been reporting that DHA itself can exert marked antimetastatic activity associated with pronounced change in the fatty acid component of tumor cells. The results indicate that uptake of DHA into tumor cells results in altered tumor cell membrane characteristics and a decreased ability to metastasize. Likewise, tumor cell drug resistance is a major problem in cancer chemotherapy. Das et al have reported that gamma-linolenic acid (GLA) of the n-6 series and eicosapentaenoic acid (EPA) of the n-3 series can potentiate the cytotoxicity of anti-cancer drugs: vincristine, cis-platinum and doxorubicin on human cervical carcinoma (HeLa) cells in vitro. Alpha-linolenic acid (ALA), GLA, EPA and docosahexaenoic acid (DHA) enhanced the uptake of vincristine by HeLa cells. In addition, DHA, EPA, GLA and DGLA were found to be cytotoxic to both vincristine-sensitive (KB-3-1) and -resistant (KB-ChR-8-5) human cervical carcinoma cells in vitro. Pre-incubation of vincristine-resistant cells with sub-optimal doses of fatty acids enhanced the cytotoxic action of vincristine. GLA, DGLA, AA, EPA and DHA enhanced the uptake and inhibited the efflux of vincristine and thus, augmented the intracellular concentration of the anti-cancer drug(s).
(Barber MD, et al. J Nutr 1999 Jun;129(6):1120-1125; Iigo M, et al. Br J Cancer 1997;75(5):650-655; Pandalai PK, et al. Anticancer Res 1996 Mar-Apr;16(2):815-820; Wigmore SJ, et al. Nutrition 1996 Jan;12(1 Suppl):S27-30; Tisdale MJ. J Nutr 1999 Jan;129(1S Suppl):243S-246S; Das UN, et al. Prostaglandins Leukot Essent Fatty Acids 1998 Jan;58(1):39-54.)

• nutritional concerns: Individuals receiving chemotherapy should consult their treating physician and/or a nutritionally trained healthcare professional about potential value of adding DHA and/or EPA to their regime before starting such supplementation.

EPA and DHA (Omega-3 Fish Oil) affecting drug toxicity: Cyclosporine

• research: Several studies have found that large doses of omega-3 fish oil (6 g per day) over three month period reduced cyclosporine-inducd kidney toxicity and the resultant decline in glomerular filtration rate by more than 50%.
(Kooijmans-Coutinho MF, et al. J Am Soc Nephrol 1996 Mar;7(3):513-518; Bilo HJK, et al. Nephron 1991;57:385-393: Badalamenti S, et al. Hepatology 1995 Dec;22(6):1695-1671; Alexander JW, et al. JPEN J Parenter Enteral Nutr 1998 May;22(3):152-155.)

• nutritional support: Reaching the levels found to be effective in studies could be difficult using standard supplementation. EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) together constitute the omega-3 fraction of fish oil. 20,000 mg of fish oil would be necessary to obtain 6,000 mg of the omega-3 fraction. Thus obtaining the required dosage would involve consuming twenty pills per day at 500 mg of omega-3 oil per pill.


Please read the disclaimer concerning the intent and limitations of the information provided here.
Do not rely solely on the information in this article.

The information presented in Interactions is for informational and educational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, case reports, and/or traditional usage with sources as cited in each topic. The results reported may not necessarily occur in all individuals and different individuals with the same medical conditions with the same symptoms will often require differing treatments. For many of the conditions discussed, treatment with conventional medical therapies, including prescription drugs or over-the-counter medications, is also available. Consult your physician, an appropriately trained healthcare practitioner, and/or pharmacist for any health concern or medical problem before using any herbal products or nutritional supplements or before making any changes in prescribed medications and/or before attempting to independently treat a medical condition using supplements, herbs, remedies, or other forms of self-care.



References

[No authors listed] Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico. Lancet. 1999 Aug 7;354(9177):447-455.
Abstract: BACKGROUND: There is conflicting evidence on the benefits of foods rich in vitamin E (alpha-tocopherol), n-3 polyunsaturated fatty acids (PUFA), and their pharmacological substitutes. We investigated the effects of these substances as supplements in patients who had myocardial infarction. METHODS: From October, 1993, to September, 1995, 11,324 patients surviving recent (< or = 3 months) myocardial infarction were randomly assigned supplements of n-3 PUFA (1 g daily, n=2836), vitamin E (300 mg daily, n=2830), both (n=2830), or none (control, n=2828) for 3.5 years. The primary combined efficacy endpoint was death, non-fatal myocardial infarction, and stroke. Intention-to-treat analyses were done according to a factorial design (two-way) and by treatment group (four-way). FINDINGS: Treatment with n-3 PUFA, but not vitamin E, significantly lowered the risk of the primary endpoint (relative-risk decrease 10% [95% CI 1-18] by two-way analysis, 15% [2-26] by four-way analysis). Benefit was attributable to a decrease in the risk of death (14% [3-24] two-way, 20% [6-33] four-way) and cardiovascular death (17% [3-29] two-way, 30% [13-44] four-way). The effect of the combined treatment was similar to that for n-3 PUFA for the primary endpoint (14% [1-26]) and for fatal events (20% [5-33]). INTERPRETATION: Dietary supplementation with n-3 PUFA led to a clinically important and statistically significant benefit. Vitamin E had no benefit. Its effects on fatal cardiovascular events require further exploration.

[No authors listed] [Omega-3 fatty acids--new panacea for a multitude of diseases]? Forsch Komplementarmed. 1999 Jun;6(3):169-70. [Article in German].

Adler AJ, Holub BJ. Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. Am J Clin Nutr. 1997 Feb;65(2):445-50.
Abstract: This study examined the effects of garlic and fish-oil supplementation (alone and in combination) on fasting serum lipids and lipoproteins in hypercholesterolemic subjects. After an initial run-in phase, 50 male subjects with moderate hypercholesterolemia were randomly assigned for 12 wk to one of four groups: 1) 900 mg garlic placebo/d + 12 g oil placebo/d; 2) 900 mg garlic/d + 12 g oil placebo/d; 3) 900 mg garlic placebo/d + 12 g fish oil/d, providing 3.6 g n-3 fatty acids/d; and 4) 900 mg garlic/d + 12 g fish oil/d. In the placebo group, mean serum total cholesterol, low-density-lipoprotein cholesterol (LDL-C), and triacylglycerols were not significantly changed in relation to baseline. Mean group total cholesterol concentrations were significantly lower with garlic+fish oil (-12.2%) and with garlic (-11.5%) after 12 wk but not with fish oil alone. Mean LDL-C concentrations were reduced with garlic+fish oil (-9.5%) and with garlic (-14.2%) but were raised with fish oil (+8.5%). Mean triacylglycerol concentrations were reduced with garlic+fish oil (-34.3%) and fish oil alone (-37.3%). The garlic groups (with and without fish oil) had significantly lower ratios of total cholesterol to high-density-lipoprotein cholesterol (HDL-C) and LDL-C to HDL-C. In summary, garlic supplementation significantly decreased both total cholesterol and LDL-C whereas fish-oil supplementation significantly decreased triacylglycerol concentrations and increased LDL-C concentrations in hypercholesterolemic men. The combination of garlic and fish oil reversed the moderate fish-oil-induced rise in LDL-C. Coadministration of garlic with fish oil was well-tolerated and had a beneficial effect on serum lipid and lipoprotein concentrations by providing a combined lowering of total cholesterol, LDL-C, and triacylglycerol concentrations as well as the ratios of total cholesterol to HDL-C and LDL-C to HDL-C.

Alexander JW, Levy A, Custer D, Valente JF, Babcock G, Ogle CK, Schroeder TJ. Arginine, fish oil, and donor-specific transfusions independently improve cardiac allograft survival in rats given subtherapeutic doses of cyclosporin. JPEN J Parenter Enteral Nutr 1998 May;22(3):152-155.

Alexander JW. Immunonutrition: the role of omega-3 fatty acids. Nutr 1998 Jul-Aug;14(7-8):627-633. (Review)
Abstract: The dietary fatty acids of the omega-3 series are rapidly incorporated into cell membranes and profoundly influence biological responses. These lipids influence membrane stability, membrane fluidity, cell mobility, the formation of receptors, binding of ligands to their receptors, activation of intracellular signaling pathways either directly or through the formation of eicosanoids, gene expression, and cell differentiation. In general, eicosanoids formed from the omega-3 fatty acids are much less potent in causing biological responses than those formed from the omega-6 fatty acids, including stimulation of cytokine production and inflammatory responses. In well-controlled clinical studies, consumption of omega-3 fatty acids has resulted in reduction of cardiovascular diseases including arrhythmias and hypertension, protection from renal disease, improvement in rheumatoid arthritis, improvement in inflammatory bowel diseases, reduced episodes of rejection, and protection from infection. The interactions between the omega-3 fatty acids and pharmacologic drugs that alter intracellular signaling pathways are only now being studied.

Assis SM, Monteiro JL, Seguro AC. L-Arginine and allopurinol protect against cyclosporine nephrotoxicity. Transplantation 1997 Apr 27;63(8):1070-1073.
Abstract: The role of nitric oxide (NO) and oxygen free radicals in cyclosporine (CsA) nephrotoxicity was investigated using L-arginine, an NO substrate, and allopurinol, a xanthine oxidase inhibitor (involved in the formation of oxygen radicals) in an experimental model with Wistar rats. CsA, administered at 15 mg/kg/body weight (BW) subcutaneously for 10 days, caused a decrease in glomerular filtration rate, with inulin clearance of 0.33+/-0.04 vs. 1.11+/-0.06 ml/min/100 g BW (P<0.01 vs. control). L-Arginine, 1.5% in drinking water 5 days before and during CsA administration, partially protected the animals against this fall in glomerular filtration rate, with inulin clearance of 0.68+/-0.03 ml/min/100 g BW (P<0.01 vs. CsA). Allopurinol, at 10 mg/kg/BW by gavage, also had a protective action, with inulin clearance of 0.54+/-0.04 ml/min/100 g (P<0.01 vs. CsA). CsA caused an elevation in NO production, as assessed by urinary excretion of its metabolites, nitrite and nitrate (NO2 and NO3; 0.836+/-0.358 vs. 0.107+/-0.019 nmol/microg creatinine). NO production was as much as threefold higher in the L-arginine group (1.853+/-0.206 nmol/g creatinine). This CsA effect is probably related to its vasoconstrictive stimulus. Supplementation with L-arginine, which provides more substrate for NO formation, may enhance vasodilatation and consequently reduce the impairment of renal function. The protection provided by allopurinol may be related to the reduced formation of oxygen radicals, preventing the deleterious effects of lipid peroxidation.

Badalamenti S, Salerno F, Lorenzano E, Paone G, Como G, Finazzi S, Sacchetta AC, Rimola A, Graziani G, Galmarini D, et al. Renal effects of dietary supplementation with fish oil in cyclosporine-treated liver transplant recipients. Hepatology 1995 Dec;22(6):1695-1671.
Abstract: Nephrotoxicity is the main untoward effect of cyclosporine (CsA) treatment. Experimental and clinical data suggest that dietary supplementation with fish oil may lessen cyclosporine nephrotoxicity, possibly by lowering renal thromboxane (Tx) production. We have studied the renal effects of a daily supplementation for 2 months of 12 g fish oil (18% C20:5 n-3 eicosapentaenoic acid [EPA] and 12% C22:6 n-3 docosahexanoic acid [DHA]) in a placebo-controlled (12 g corn oil), prospective, randomized, double-blind study of stable CsA-treated liver transplant recipients. Thirteen patients ingested corn oil capsules and 13 fish oil. Compliance with dietary regimen was confirmed by fatty acid chromatography that showed increased plasma concentrations of EPA (from 0.4 +/- 0.02% to 4.6 +/- 0.5%, P < .0001) and DHA (from 1.8 +/- 0.2% to 3.9 +/- 0.1%, P < .0001) in the fish oil group and increased plasma concentration of linoleic acid (C18:2 n-6) in the corn oil group (from 25 +/- 2% to 28.4 +/- 2%, P < .001). At the end of the 2 months of the study, in the fish oil group the effective renal plasma flow increased by 22% (P = .012), the glomerular filtration rate increased by 33% (P = .057), the renal blood flow increased by 17% (P = .024), and the calculated total renal vascular resistances decreased by 20% (P = .034). In contrast, none of these parameters changed in the corn oil group. The renal functional reserve determined during L-arginine infusion, plasma renin activity (PRA), and plasma aldosterone (PA) remained unchanged during the study in either group.

Barber MD. Diet and prevention of cancer. Consumption of oily fish should be encouraged. BMJ. 1999 Jul 17;319(7203):187; discussion 187-188.

Barber MD, Ross JA, Preston T, Shenkin A, Fearon KC. Fish oil-enriched nutritional supplement attenuates progression of the acute-phase response in weight-losing patients with advanced pancreatic cancer. J Nutr 1999 Jun;129(6):1120-1125.
Abstract: The presence of an acute-phase protein response (APPR) has been suggested to shorten survival and contribute to weight loss in patients with pancreatic cancer. Fatty acids derived from fish oil have been shown to alter proinflammatory cytokine production and acute-phase protein synthesis in vitro. The present study was designed to determine the effects of a fish oil-enriched nutritional supplement on the concentrations of a range of individual acute-phase proteins (APP) in patients with advanced pancreatic cancer. In a sequential series, 18 patients with pancreatic cancer received the supplement (providing 2 g eicosapentaenoic acid and 1 g docosahexaenoic acid/d) for 3 wk while another 18 received full supportive care alone. Six healthy subjects served as additional controls. Acute-phase proteins were measured before and after the 3-wk intervention period in cancer patients. At baseline, albumin, transferrin and pre-albumin were significantly reduced and fibrinogen, haptoglobin, alpha-1-acid glycoprotein, alpha-1-antitrypsin, ceruloplasmin and C-reactive protein (CRP) were significantly elevated in the cancer patients compared with healthy controls, reflecting their roles as negative and positive acute phase proteins, respectively. In the supplemented cancer group, the only significant change in APP concentrations over the 4-wk study period was an increase in transferrin. In the control cancer group there were further significant reductions in albumin, transferrin and pre-albumin, and a significant increase in CRP concentration. These results suggest that many positive and negative APP are altered in advanced pancreatic cancer. The APPR tends to progress in untreated patients but may be stabilized by the administration of a fish oil-enriched nutritional supplement. This may have implications for reducing wasting in such patients.

Belluzzi A, Brignola C, Campieri M, Pera A, Boschi S, Miglioli M. Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease. N Engl J Med. 1996 Jun 13;334(24):1557-1560.
Abstract: BACKGROUND: Patients with Crohn's disease may have periods of remission, interrupted by relapses. Because fish oil has antiinflammatory actions, it could reduce the frequency of relapses, but it is often poorly tolerated because of its unpleasant taste and gastrointestinal side effects. METHODS: We performed a one-year, double-blind, placebo-controlled study to investigate the effects of a new fish-oil preparation in the maintenance of remission in 78 patients with Crohn's disease who had a high risk of relapse. The patients received either nine fish-oil capsules containing a total of 2.7 g of n-3 fatty acids or nine placebo capsules daily. A special coating protected the capsules against gastric acidity for at least 30 minutes. RESULTS: Among the 39 patients in the fish-oil group, 11 (28 percent) had relapses, 4 dropped out because of diarrhea, and 1 withdrew for other reasons. In contrast, among the 39 patients in the placebo group, 27 (69 percent) had relapses, 1 dropped out because of diarrhea, and 1 withdrew for other reasons (difference in relapse rate, 41 percentage points; 95 percent confidence interval, 21 to 61; P < 0.001). After one year, 23 patients (59 percent) in the fish-oil group remained in remission, as compared with 10 (26 percent) in the placebo group (P = 0.003). Logistic-regression analysis indicated that only fish oil and not sex, age, previous surgery, duration of disease, or smoking status affected the likelihood of relapse (odds ratio for the placebo group as compared with the fish-oil group, 4.2; 95 percent confidence interval, 1.6 to 10.7). CONCLUSIONS: In patients with Crohn's disease in remission, a novel enteric-coated fish-oil preparation is effective in reducing the rate of relapse.

Belluzzi A, Brignola C, Campieri M, Camporesi EP, Gionchetti P, Rizzello F, Belloli C, De Simone G, Boschi S, Miglioli M, et al. Effects of new fish oil derivative on fatty acid phospholipid-membrane pattern in a group of Crohn's disease patients. Dig Dis Sci. 1994 Dec;39(12):2589-2594.
Abstract: Fish oil has been recently proposed as a possible effective treatment in inflammatory bowel disease (IBD); however, a lot of annoying side effects (ie, belching, halitosis, diarrhea, etc) affect patient compliance. We carried out a study of patient tolerance in a group of Crohn's disease (CD) patients with a new fish oil derivative consisting of 500-mg capsules of eicosapentaenoic-docosahexaenoic (EPA 40%-DHA 20%), a free fatty acid mixture (Purepa), and we also evaluated its incorporation into phospholipids, both in plasma and in red cell membranes. Five groups of 10 CD patients in remission received nine Purepa capsules daily in four different preparations (A: uncoated, B: coated, pH 5.5; C: coated, pH 5.5, 60 min time release; D: coated, pH 6.9) and 12 x 1-g capsules daily of a triglyceride preparation (Max-EPA, EPA 18%-DHA 10%), respectively. We coated three of the four Purepa preparations in order to delay the release of contents in an attempt to minimize the side effects. After six weeks of treatment, the group taking Purepa capsules, coated, pH 5.5, 60 min time release (group C) showed the best incorporation of EPA and DHA in red blood cell phospholipid membranes (EPA from 0.2 to 4.4%, DHA from 3.7 to 6.3%), and no side effects were registered, whereas in all other groups side effects were experienced in 50% or more of subjects. This new preparation will make it possible to treat patients for long periods.

Belluzzi A, et al. Polyunsaturated fatty acid pattern and fish oil treatment in inflammatory bowel disease. Gut. 1993 Sep;34(9):1289-1290.

Bilo HJ, Homan van der Heide JJ, Gans RO, Donker AJ. Omega-3 polyunsaturated fatty acids in chronic renal insufficiency. Nephron 1991;57(4):385-393. (Editorial; Review)

Braden LM, Carroll KK. Dietary polyunsaturated fat in relation to mammary carcinogenesis in rats. Lipids 1986;21(4):285.

Clarke JT, Cullen-Dean G, Regelink E, Chan L, Rose V. Increased incidence of epistaxis in adolescents with familial hypercholesterolemia treated with fish oil. J Pediatr. 1990 Jan;116(1):139-141.

Das UN, Madhavi N, Sravan Kumar G, Padma M, Sangeetha P. Can tumour cell drug resistance be reversed by essential fatty acids and their metabolites? Prostaglandins Leukot Essent Fatty Acids 1998 Jan;58(1):39-54.
Tumour cell drug resistance is a major problem in cancer chemotherapy. Essential fatty acids have been shown to be cytotoxic to a variety of tumour cells in vitro. But, the effect of these fatty acids on tumour cell drug resistance has not been well characterized. Gamma-linolenic acid (GLA) of the n-6 series and eicosapentaenoic acid (EPA) of the n-3 series potentiated the cytotoxicity of anti-cancer drugs: vincristine, cis-platinum and doxorubicin on human cervical carcinoma (HeLa) cells in vitro. Alpha-linolenic acid (ALA), GLA, EPA and docosahexaenoic acid (DHA) enhanced the uptake of vincristine by HeLa cells. In addition, DHA, EPA, GLA and DGLA were found to be cytotoxic to both vincristine-sensitive (KB-3-1) and -resistant (KB-ChR-8-5) human cervical carcinoma cells in vitro. Pre-incubation of vincristine-resistant cells with sub-optimal doses of fatty acids enhanced the cytotoxic action of vincristine. GLA, DGLA, AA, EPA and DHA enhanced the uptake and inhibited the efflux of vincristine and thus, augmented the intracellular concentration of the anti-cancer drug(s). Fatty acid analysis of KB-3-1 and KB-ChR-8-5 cells showed that the latter contained low amounts of ALA, GLA, 22:5 n-3 and DHA in comparison to the vincristine-sensitive cells. The concentrations of GLA and DHA were increased 10-15 fold in the phospholipid, free fatty acid and ether lipid cellular lipid pools of GLA and DHA treated cells. These results coupled with the observation that various fatty acids can alter the activity of cell membrane bound enzymes such as sodium-potassium-ATPase and 5'-nucleotidase, levels of various anti-oxidants, p53 expression and the concentrations of protein kinase C suggest that essential fatty acids and their metabolites can reverse tumour cell drug-resistance at least in vitro.

de Lorgeril M, Salen P, Martin JL, et al. Mediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Diet Heart Study. Circulation 1999;99:779-785.

DiGiacoma RA, Kremer JM, Shah DM. Fish-oil dietary supplementation in patients with Raynaud’s phenomenon: A double-blind, controlled, prospective study. Am J Med. 1989 Feb;86(2):158-164.
Abstract: PURPOSE: The ingestion of omega-3 fatty acids could benefit patients with Raynaud's phenomenon because, among other effects, these fatty acids induce a favorable vascular response to ischemia. The aim of our study was to investigate, in a double-blind, placebo-controlled manner, the effects of fish-oil fatty-acid dietary therapy in patients with rheumatic disease. PATIENTS AND METHODS: Thirty-two patients with primary or secondary Raynaud's phenomenon were randomly assigned to olive-oil placebo or fish-oil groups. Patients ingested 12 fish-oil capsules daily containing a total of 3.96 g eicosapentaenoic acid and 2.64 g docosahexaenoic acid or 12 olive-oil capsules and were evaluated at baseline and after six, 12, and 17 weeks. All patients ingested olive oil between Weeks 12 to 17. Digital systolic blood pressures and blood flow were measured at room air and water baths of 40 degrees C, 25 degrees C, 15 degrees C, and 10 degrees C using strain gauge plethysmography. Onset of Raynaud's phenomenon was timed with a stop watch and defined as plethysmographic evidence of cessation of blood flow and blood pressure in the study finger. RESULTS: In the fish-oil group, the median time interval before the onset of Raynaud's phenomenon increased from 31.3 +/- 1.3 minutes baseline to 46.5 +/- 2.1 minutes at six weeks (p = 0.04). Patients with primary Raynaud's phenomenon ingesting fish oil had the greatest increase in the time interval before the onset of the condition. Five of 11 patients (45.5 percent) with primary Raynaud's phenomenon ingesting fish oil in whom the phenomenon was induced at baseline could not be induced to develop Raynaud's at the six- or 12-week visit compared with one of nine patients (11 percent) with primary Raynaud's ingesting olive oil (p = 0.05). The mean digital systolic pressures were higher in the patients with primary Raynaud's phenomenon ingesting fish oil than in patients with primary Raynaud's ingesting olive oil in the 10 degrees C water bath (+32 mm Hg, p = 0.02). CONCLUSION: We conclude that the ingestion of fish oil improves tolerance to cold exposure and delays the onset of vasospasm in patients with primary, but not secondary, Raynaud's phenomenon. These improvements are associated with significantly increased digital systolic blood pressures in cold temperatures.

Donadio JV Jr, Bergstralh EJ, Offord KP, Spencer DC, Holley KE. A controlled trial of fish oil in IgA nephropathy. Mayo Nephrology Collaborative Group. N Engl J Med 1994 Nov 3;331(18):1194-1199.
Abstract: BACKGROUND. The n-3 fatty acids in fish oil affect eicosanoid and cytokine production and therefore have the potential to alter renal hemodynamics and inflammation. The effects of fish oil could prevent immunologic renal injury in patients with IgA nephropathy. METHODS. In a multicenter, placebo-controlled, randomized trial we tested the efficacy of fish oil in patients with IgA nephropathy who had persistent proteinuria. The daily dose of fish oil was 12 g; the placebo was a similar dose of olive oil. Serum creatinine concentrations, elevated in 68 percent of the patients at base line, and creatinine clearance were measured for two years. The primary end point was an increase of 50 percent or more in the serum creatinine concentration at the end of the study. RESULTS. Fifty-five patients were assigned to receive fish oil, and 51 to receive placebo. According to Kaplan-Meier estimation, 3 patients (6 percent) in the fish-oil group and 14 (33 percent) in the placebo group had increases of 50 percent or more in their serum creatinine concentrations during treatment (P = 0.002). The annual median changes in the serum creatinine concentrations were 0.03 mg per deciliter (2.7 mumol per liter) in the fish-oil group and 0.14 mg per deciliter (12.4 mumol per liter) in the placebo group. Proteinuria was slightly reduced and hypertension was controlled to a comparable degree in both groups. The cumulative percentage of patients who died or had end-stage renal disease was 40 percent in the placebo group after four years and 10 percent in the fish-oil group (P = 0.006). No patient discontinued fish-oil treatment because of adverse effects. CONCLUSIONS. In patients with IgA nephropathy, treatment with fish oil for two years retards the rate at which renal function is lost.

Donadio JV Jr, Grande JP, Bergstralh EJ, Dart RA, Larson TS, Spencer DC. The long-term outcome of patients with IgA nephropathy treated with fish oil in a controlled trial. Mayo Nephrology Collaborative Group. J Am Soc Nephrol. 1999 Aug;10(8):1772-1777.
Abstract: It was reported previously that dietary fish oil supplementation retarded the progression of renal disease in patients with IgA nephropathy in a multicenter, placebo-controlled, randomized, 2-yr clinical trial. The aim of this study was to determine the long-term influence of fish oil treatment on renal progression in observations on the study cohort of 106 patients extending beyond the 2-yr trial. Renal function was assessed by serial serum creatinine and 24-h urine protein measurements. Vital, end-stage renal disease (ESRD), and BP status and treatment beyond completion of the 2-yr trial were determined. As in the trial, the primary end point was an increase of 50% or more in the serum creatinine, and the secondary end point was ESRD. After a mean follow-up of 6.4 yr, 46 patients-17 in the fish oil group versus 29 in the placebo group-reached the primary end point (P = 0.002), and 27 patients-eight in the fish oil group versus 19 in the placebo group-developed ESRD (P = 0.009). At the end of the 2-yr trial, 75 patients (45 fish oil, 30 placebo) remained at risk for the primary end point. This is also when the double-blind part of the trial ended, allowing physicians to stop supplements, switch original placebo-assigned patients to fish oil, and continue fish oil in original fish oil-assigned patients. A significantly greater number of nonsupplemented placebo patients developed the primary end point (P = 0.02) and ESRD (P = 0.003) compared with long-term supplemented fish oil patients. Conversely, more fish oil-supplemented patients had stable renal function than nonsupplemented patients (P = 0.02). By intention, BP control, primarily treated with angiotensin-converting enzyme inhibition, was equal in the fish oil and placebo groups. Proteinuria was modestly reduced in both groups. It is concluded that early and prolonged treatment with fish oil slows renal progression for high-risk patients with IgA nephropathy.

Dunstan DW, Mori TA, Puddey IB, Beilin LJ, Burke V, Morton AR, Stanton KG. The independent and combined effects of aerobic exercise and dietary fish intake on serum lipids and glycemic control in NIDDM. A randomized controlled study. Diabetes Care. 1997 Jun;20(6):913-921.
Abstract: OBJECTIVE: The triglyceride-lowering effects of omega-3 fats and HDL cholesterol-raising effects of exercise may be appropriate management for dyslipidemia in NIDDM. However, fish oil may impair glycemic control in NIDDM. The present study examined the effects of moderate aerobic exercise and the incorporation of fish into a low-fat (30% total energy) diet on serum lipids and glycemic control in dyslipidemic NIDDM patients. RESEARCH DESIGN AND METHODS: In a controlled, 8-week intervention, 55 sedentary NIDDM subjects with serum triglycerides > 1.8 mmol/l and/or HDL cholesterol < 1.0 mmol/l were randomly assigned to a low-fat diet (30% daily energy intake) with or without one fish meal daily (3.6 g omega-3/day) and further randomized to a moderate (55-65% VO2max) or light (heart rate < 100 bpm) exercise program. An oral glucose tolerance test (75 g), fasting serum glucose, insulin, lipids, and GHb were measured before and after intervention. Self-monitoring of blood glucose was performed throughout. RESULTS: In the 49 subjects who completed the study, moderate exercise improved aerobic fitness (VO2max) by 12% (from 1.87 to 2.07 l/min, P = 0.0001). Fish consumption reduced triglycerides (0.80 mmol/l, P = 0.03) and HDL3 cholesterol (0.05 mmol/l, P = 0.02) and increased HDL2 cholesterol (0.06 mmol/l, P = 0.01). After adjustment for age, sex, and changes in body weight, fish diets were associated with increases in GHb (0.50%, P = 0.05) and self-monitored glucose (0.57 mmol/l, P = 0.0002), which were prevented by moderate exercise. CONCLUSIONS: A reduced fat diet incorporating one daily fish meal reduces serum triglycerides and increases HDL2 cholesterol in dyslipidemic NIDDM patients. Associated deterioration in glycemic control can be prevented by a concomitant program of moderate exercise.

Gonzalez MJ. Fish oil, lipid peroxidation and mammary tumor growth. J Am Coll Nutr 1995;14:325.

Haglund O, Luostarinen R, Wallin R, Wibell L, Saldeen T. The effects of fish oil on triglycerides, cholesterol, fibrinogen and malondialdehyde in humans supplemented with vitamin E. J Nutr. 1991 Feb;121(2):165-169.

Harris WS, Dujovne CA, Zucker M, Johnson B. Effects of a low saturated fat, low cholesterol fish oil supplement in hypertriglyceridemic patients. A placebo-controlled trial. Ann Intern Med. 1988 Sep 15;109(6):465-470.

Harris WS, Zucker ML, Dujovne CA. Omega-3 fatty acids in type IV hyperlipidemia: fish oils vs methyl esters. Am J Clin Nutr. 1988 Oct;48(4):992-997.
Abstract: The purpose of this study was to compare the relative effects of omega-3 fatty acids (omega-3 FAs) in the triglyceride (TG) and methly ester (ME) forms in a crossover design in patients with type IV hyperlipidemia. Eight male patients were given 18 vegetable-oil capsules (control); 18 capsules of a TG rich in omega-3 FAs (omega-3 TG); and 11 capsules containing omega-3-FA MEs (omega-3 ME). One supplement was given during each of three 6-wk periods. Equivalent amounts of omega-3 FAs (6.8 g/d) were provided by each of the omega-3 treatments. Plasma cholesterol (C) levels were unchanged during the two omega-3 phases whereas plasma TG levels fell by 44% during both. Low-density-lipoprotein cholesterol (LDL-C) levels rose significantly with both omega-3-FA treatments, as did apolipoprotein B levels. When taken in either the TG or ME forms, omega-3 FAs are equally effective hypotriglyceridemic agents but they may raise LDL-C levels.

Hawthorne AB, Daneshmend TK, Hawkey CJ, Belluzzi A, Everitt SJ, Holmes GK, Malkinson C, Shaheen MZ, Willars JE. Treatment of ulcerative colitis with fish oil supplementation: a prospective 12 month randomised controlled trial. Gut. 1992 Jul;33(7):922-928.

Horrobin DF. Schizophrenia as a prostaglandin deficiency disease. Lancet. 1977;1:936-937.

Horrobin DF, Glen AI, Vaddadi K. The membrane hypothesis of schizophrenia. Schizophr Res. 1994;13:195-207.

Iigo M, Nakagawa T, Ishikawa C, Iwahori Y, Asamoto M, Yazawa K, Araki E, Tsuda H. Inhibitory effects of docosahexaenoic acid on colon carcinoma 26 metastasis to the lung. Br J Cancer 1997;75(5):650-655.
Abstract: Unsaturated fatty acids, including n-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (C22:6, DHA) and eicosapentaenoic acid (C20:5, EPA), and a series of n-6 PUFAs were investigated for their anti-tumour and antimetastatic effects in a subcutaneous (s.c.) implanted highly metastatic colon carcinoma 26 (Co 26Lu) model. EPA and DHA exerted significant inhibitory effects on tumour growth at the implantation site and significantly decreased the numbers of lung metastatic nodules. Oleic acid also significantly inhibited lung metastatic nodules. Treatment with arachidonic acid showed a tendency for reduction in colonization. However, treatment with high doses of fatty acids, especially linoleic acid, increased the numbers of lung metastatic nodules. DHA and EPA only inhibited lung colonizations when administered together with the tumour cells, suggesting that their incorporation is necessary for an influence to be exerted. Chromatography confirmed that contents of fatty acids in both tumour tissues and plasma were indeed affected by the treatments. Tumour cells pretreated with fatty acids in vivo, in particular DHA, also showed a low potential for lung colony formation when transferred to new hosts. Thus, DHA treatment exerted marked antimetastatic activity associated with pronounced change in the fatty acid component of tumour cells. The results indicate that uptake of DHA into tumour cells results in altered tumour cell membrane characteristics and a decreased ability to metastasize.

Kooijmans-Coutinho MF, Rischen-Vos J, Hermans J, Arndt JW, van der Woude FJ. Dietary fish oil in renal transplant recipients treated with cyclosporin-A: no beneficial effects shown. J Am Soc Nephrol 1996 Mar;7(3):513-518.
Abstract: This study aimed to determine whether dietary supplementation with fish oil has a beneficial effect on graft function and the incidence of rejection in renal allograft recipients treated with cyclosporin A (CsA). Renal function, blood pressure, the incidence of acute rejection episodes, graft survival, and renal histology and immunochemistry were investigated. In a randomized, placebo-controlled, double-blind trial, groups of 25 recipients of primary cadaveric renal allografts who had been treated with CsA took fish oil (30% C20:5 omega-3 and 20% C22:6 omega-3) or coconut oil (63% C8:0 and 36% C10:0) at 6 g/day for 3 months. There were no differences between the two patient groups with regard to HLA matching, panel-reactive antibody titers, or the demographic characteristics of donors or recipients. The GFR and effective RPF were determined at 1, 3, and 12 months after transplantation by simultaneous measurement of (125I-)iothalamate and (131I) hippuran clearances. At 1 yr after transplantation, patients treated with fish oil showed better renal function than did the control patients, but this difference was not statistically significant. Blood pressure and antihypertensive drug use were similar in both groups. The number of rejection episodes was also similar, and renal histopathological and immunohistochemical studies showed no significant differences between the fish-oil group and the control patients. It is concluded that fish oil, at a dose of 6 g/day, has no beneficial effect after renal transplantation within the time scale of the study.

Laugharne JDE, Mellor JE, Peet M. Fatty acids and schizophrenia. Lipids. 1996 Mar;31 Suppl:S163-165.
Abstract: In a controlled study of red cell membrane fatty acids in patients with schizophrenia, substantial depletions of fatty acids from both the n-6 and n-3 series were demonstrated. Arachidonic acid and docosahexaenoic acid were particularly depleted. In a separate study, dietary analysis revealed no deficiency of fatty acid intake in this patient group, but greater intake of n-3 fatty acids was associated with less severe symptomatology. Dietary supplementation for six weeks with 10 g per day of concentrated fish oil (MaxEPA) led to significant improvement in schizophrenic symptoms. This clinical improvement was related to the increased level of n-3 fatty acids in red cell membranes. These findings form part of a growing body of research data suggestive of an abnormality in cell membrane fatty acid composition in schizophrenia. The preliminary evidence for clinically effective dietary manipulation to correct such an abnormality opens up novel and exciting therapeutic possibilities.

Leaf, A. Dietary Prevention of Coronary Heart Disease: The Lyon Diet Heart Study. Circulation 1999;99:733-735.

Leaf A, Weber PC. Cardiovascular effects of n-3 fatty acids. N Engl J Med. 1988 Mar 3;318(9):549-557. (Review)

Luostarinen R, Wallin R, Wibell L, et al. Vitamin E supplementation counteracts the fish oil-induced increase of blood glucose in humans. Nutr Res 1995; 15:953-968.

Malasanos TH, Stacpoole PW. Biological effects of omega-3 fatty acids in diabetes mellitus. Diabetes Care. 1991 Dec;14(12):1160-1179. (Review)

Mate J, Castanos R, Garcia-Samaniego J, Pajares JM. Does dietary fish oil maintain the remission of Crohn’s disease: a case control study. Gastroenterology 1991;100:A228.

Mellor JE, Laugharne JDE, Peet M. Omega-3 fatty acid supplementation in schizophrenic patients. Hum Psychopharmacol. 1996;11:39-46.

Nair SS, Leitch JW, Falconer J, Garg ML. Prevention of cardiac arrhythmia by dietary (n-3) polyunsaturated fatty acids and their mechanism of action. J Nutr. 1997 Mar;127(3):383-393. (Review)
Abstract: The role of marine fish oil (n-3) polyunsaturated fatty acids in the prevention of fatal ventricular arrhythmia has been established in experimental animals. Prevention of arrhythmias arising at the onset of ischemia and reperfusion is important because if untreated, they result in sudden cardiac death. Animals supplemented with fish oils in their diet developed little or no ventricular fibrillation after ischemia was induced. Similar effects have also been observed in cultured neonatal cardiomyocytes. Several mechanisms have been proposed and studied to explain the antiarrhythmic effects of fish oil polyunsaturated fatty acids, but to date, no definite mechanism has been validated. The sequence of action of these mechanisms and whether more than one mechanism is involved is also not clear. Some of the mechanisms suggested to explain the antiarrhythmic action of fish oils include the incorporation and modification of cell membrane structure by (n-3) polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their role in eicosanoid metabolism. Other mechanisms that are currently being investigated include the role of (n-3) polyunsaturated fatty acids in cell signalling mediated through phosphoinositides and their effect on various enzymes and receptors. This article reviews these mechanisms and the antiarrhythmic studies using (n-3) polyunsaturated fatty acids.

Pandalai PK, Pilat MJ, Yamazaki K, Naik H, Pienta KJ. The effects of omega-3 and omega-6 fatty acids on in vitro prostate cancer growth. Anticancer Res 1996 Mar-Apr;16(2):815-820.
Dietary intake of essential fatty acids (EFA) may play a role in prostate cancer cell proliferation. Epidemiological studies have demonstrated that men whose dietary intake is high in omega-3 fatty acid (FA) composition have a lower incidence of clinical prostate cancer, suggesting that external factors such as diet may play an important role in development and growth of prostate cancer. Furthermore, in prostate cancer cell lines, omega-6 and omega-3 FAs have demonstrated promotional and inhibitory effects respectively. To investigate the effects of dietary fats on nontumorigenic prostate cell growth we conducted in vitro studies with human metastatic PC-3, LNCaP and TSU prostate cell lines, the rat metastatic Mat-Ly-Lu cell line and rat non-metastatic epithelial cell lines EPYP1, EPYP2 and EPYP3. Cell lines were treated with linoleic acid (LA), an omega-6 FA (n-6), as well as linolenic (LLA) and eicosapentaenoic (EPA) acids, which are both omega-3 FAs (n-3). All cell lines were treated with 10% and 0.5% serum supplemented media plus fatty acid for comparison. Our results demonstrate that linoleic acid(n-6) has promotional effects at doses of 1-100ng/ml in all cell lines with the exception of EPYPl. Experiments with linolenic acid (n-3) demonstrated consistent growth promotion in all cell lines examined with the exception of the EPYP2 cell line in which there was no significant effect. EPA had no effect in culture media supplemented with 10% serum, while in media containing 0.5% serum this FA demonstrated significant promotion in all human lines. Previous studies have indicated that EPA should inhibit human prostate cancer growth in vitro, however our results demonstrated promotion at low concentrations (lng/ml). At higher concentrations, EPA did inhibit prostate cell growth. These data indicate low levels of dietary fat, regardless of composition, may play a role in prostate cancer proliferation and could be an avenue for therapeutic intervention.

Peck LW. Essential fatty acid deficiency in renal failure: can supplements really help? J Am Dietet Assoc 1997 Oct;97(10 Suppl 2):S150-S153. (Review)
Abstract: Abnormal fatty acid metabolism may contribute to clinical problems such as itching, abnormal perspiration, susceptibility to infection, delayed wound healing, anemia, and increased hemolysis, as seen in patients with chronic renal failure. A double-blind study of patients on hemodialysis who received either fish oil, olive oil, or safflower oil documented that patients may have increased levels of the proinflammatory prostaglandin PGE2 and that fish oil intervention may decrease these levels, change the fatty acid profile, improve hematocrit levels, and improve patient perception of symptoms of pruritus.

Peck MD. Omega-3 polyunsaturated fatty acids: benefit or harm during sepsis? New Horiz. 1994 May;2(2):230-236. (Review)

Peet M, Laugharne JDE, Mellor J, Ramchand CN. Essental fatty acid deficiency in erythrocyte membranes from chronic schizophrenic patients, and the clinical effects of dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 1996;55:71-75.

Peet M, Laugharne JDE, Mellor J. Double-blind trial of n-3 fatty acid supplementation in the treatment of schizophrenia. Presented at the International Congress on Schizophrenia Research; April 1997; Colorado Springs, Colo.

Piche LA, Draper HH, Cole PD. Malondialdehyde excretion by subjects consuming cod liver oil vs a concentrate of n-3 fatty acids. Lipids. 1988 Apr;23(4):370-371.

Schectman G, Kaul S, Kassebah AH. Effect of fish oil concentrate on lipoprotein composition in NIDDM. Diabetes 1988 Nov;37(11):1567-1573.
ABSTRACT: Non-insulin-dependent diabetes mellitus (NIDDM) is associated with elevated very-low-density lipoprotein (VLDL) triglyceride concentrations and abnormalities of low-density lipoprotein (LDL) composition. Because fish oil supplementation may favorably affect lipid and lipoprotein concentrations in nondiabetic subjects, we determined the effect of fish oil concentrate on plasma lipids and lipoprotein composition in patients with NIDDM. Dietary-supplementation 1-mo periods of 4.0 and 7.5 g of omega-3 fatty acids in fish oil were compared with a placebo of 12 g safflower oil by use of a single-blind crossover design. Medications, including antidiabetic therapy, were continued through the study. Compared with safflower oil treatment, fish oil supplementation resulted in a significant reduction of total plasma triglycerides of 24% at the 4-g dose and a larger reduction of 39% at the 7.5-g dose. These decreases were due to similar reductions in VLDL triglycerides. LDL cholesterol levels were mildly elevated, but a larger 20% increase in LDL apolipoprotein B (apoB) concentration was observed. During supplementation with the fish oil concentrate, the LDL cholesterol-to-apoB ratio was significantly reduced when compared with pretreatment values, but not when compared with safflower oil treatment. High-density lipoprotein (HDL) cholesterol and plasma apoA1 levels were not significantly changed during fish oil treatment. At the 7.5-g dose, fasting glucose and glycohemoglobin levels increased by 20 and 12%, respectively, but were unchanged at the lower level of supplementation. Thus, in NIDDM patients, dietary supplementation with omega-3 fatty acids induces a reduction in total plasma and VLDL triglyceride levels.

Shahar E, Folsom AR, Melnick SL, Tockman MS, Comstock GW, Gennaro V, Higgins MW, Sorlie PD, Ko WJ, Szklo M. Dietary n-3 polyunsaturated fatty acids and smoking-related chronic obstructive pulmonary disease. Atherosclerosis Risk in Communities Study Investigators. N Engl J Med. 1994 Jul 28;331(4):228-233.
Abstract: BACKGROUND. Fish contain n-3 polyunsaturated fatty acids, principally eicosapentaenoic acid and docosahexaenoic acid, which are known to interfere with the body's inflammatory response and may be of benefit in chronic inflammatory conditions. METHODS. We studied the relation between the dietary intake of n-3 fatty acids and chronic obstructive pulmonary disease (COPD) in 8960 current or former smokers participating in a population-based study of atherosclerosis. Intake of fatty acids was estimated with a dietary questionnaire. The presence of COPD was assessed by a questionnaire on respiratory symptoms and by spirometry. Three case definitions of COPD were used: symptoms of chronic bronchitis (667 subjects), physician-diagnosed emphysema reported by the subject (185 subjects), and spirometrically detected COPD (197 subjects). RESULTS. After control for pack-years of smoking, age, sex, race, height, weight, energy intake, and educational level, the combined intake of eicosapentaenoic acid and docosahexaenoic acid was inversely related to the risk of COPD in a quantity-dependent fashion. The adjusted odds ratio for the highest quartile of intake as compared with the lowest quartile was 0.66 for chronic bronchitis (95 percent confidence interval, 0.52 to 0.85; P < 0.001 for linear trend across the range of intake values), 0.31 for physician-diagnosed emphysema (95 percent confidence interval, 0.18 to 0.52; P for linear trend, 0.003), and 0.50 for spirometrically detected COPD (95 percent confidence interval, 0.32 to 0.79; P for linear trend, 0.007). CONCLUSIONS. A high dietary intake of n-3 fatty acids may protect cigarette smokers against COPD.

Sheehan JP, Wei IW, Ulchaker M, Tserng K-Y. Effect of high fiber intake in fish oil-treated patients with non-insulin-dependent diabetes mellitus. Am J Clin Nutr. 1997 Nov;66(5):1183-1187.
Abstract: The short-term effect of high fiber intake on fish-oil treatment in 15 free-living, non-insulin-dependent diabetic patients was evaluated by using a controlled, sequential study design. During an 8-wk fish-oil-treatment period when patients received 20 g fish oil/d, the usual daily fiber intake was increased with a 15-g pectin supplement at midpoint. Fish oil alone lowered triacylglycerol and very-low-density-lipoprotein-cholesterol concentrations by 41% and 36%, respectively (both P < 0.01 by the end of the treatment period) with unchanged mean total, low-density-, and high-density-lipoprotein-cholesterol concentrations. When the fiber intake was increased, however, total and low-density-lipoprotein-cholesterol concentrations decreased significantly (P < 0.001 and < 0.05, respectively) with fish-oil treatment. The cholesterol ester fraction of plasma lipids was reduced by 34% when compared with fish oil alone (P < 0.05). The plasma triacylglycerol fraction decreased further by 44% (P < 0.001). Other beneficial effects observed included a 30% decline in the fatty acid fraction (P < 0.002) by end of the treatment period. Diabetic control was maintained during the 12-wk study. In conclusion, a high fiber intake may be beneficial in fish oil-treated diabetic patients.

Siguel, E. A new relationship between PUFAs and TC/HDLC. Lipids, 1996; 31, S51-S56.

Siguel E, Lerman RH, MacBeath, B. Low-Fat Diets for Coronary Heart Disease: Perhaps, But Which One? JAMA, 1996:275: 1402-1403.

Siguel EN, Lerman, RH. Fatty Acid Patterns in Patients With Angiographically Documented CAD. Metabolism 1994; 43:982-993.

Siguel EN. Essential Fatty Acids in Health and Disease. Brookline, MA: Nutrek Press, 1994.

Simopoulos AP. Essential fatty acids in health and chronic disease.Am J Clin Nutr. 1999 Sep;70(3 Suppl):560S-9S.
Abstract: Human beings evolved consuming a diet that contained about equal amounts of n-3 and n-6 essential fatty acids. Over the past 100-150 y there has been an enormous increase in the consumption of n-6 fatty acids due to the increased intake of vegetable oils from corn, sunflower seeds, safflower seeds, cottonseed, and soybeans. Today, in Western diets, the ratio of n-6 to n-3 fatty acids ranges from approximately 20-30:1 instead of the traditional range of 1-2:1. Studies indicate that a high intake of n-6 fatty acids shifts the physiologic state to one that is prothrombotic and proaggregatory, characterized by increases in blood viscosity, vasospasm, and vasoconstriction and decreases in bleeding time. n-3 Fatty acids, however, have antiinflammatory, antithrombotic, antiarrhythmic, hypolipidemic, and vasodilatory properties. These beneficial effects of n-3 fatty acids have been shown in the secondary prevention of coronary heart disease, hypertension, type 2 diabetes, and, in some patients with renal disease, rheumatoid arthritis, ulcerative colitis, Crohn disease, and chronic obstructive pulmonary disease. Most of the studies were carried out with fish oils [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)]. However, alpha-linolenic acid, found in green leafy vegetables, flaxseed, rapeseed, and walnuts, desaturates and elongates in the human body to EPA and DHA and by itself may have beneficial effects in health and in the control of chronic diseases.

Tisdale MJ. Inhibition of lipolysis and muscle protein degradation by EPA in cancer cachexia. Nutrition 1996 Jan;12(1 Suppl):S31-33.
Abstract: Depletion of muscle and adipose tissue in cancer cachexia appears to arise not only from decreased food intake but also from the production of catabolic factors by certain tumours. Experiments with the cachexia-inducing MAC16 tumour in mice showed that when part of the carbohydrate calories were replaced by fish oil, host body weight loss was inhibited. The effect occurred without an alteration of either the total calorie consumption or nitrogen intake. Instead, one of the polyunsaturated fatty acids (PUFA) in fish oil, eicosapentaenoic acid (EPA), was found directly to inhibit tumour-induced lipolysis. The effect was structurally specific, as two related PUFA, docosahexaenoic acid (DHA) and gamma-linolenic acid (GLA), were without effect. The antilipolytic effect of EPA arose from an inhibition of the elevation of cyclic AMP in adipocytes in response to the lipid mobilizing factor. The increased protein degradation in the skeletal muscle of cachectic animals was also inhibited by EPA. This effect was due to the inhibition of the rise in muscle prostaglandin E2 in response to a tumour-produced proteolytic factor by EPA. Thus, reversal of cachexia by EPA in this mouse model results from its capacity to interfere with tumour-produced catabolic factors. Similar factors have been detected in human cancer cachexia.

Tisdale MJ. Wasting in cancer. J Nutr 1999 Jan;129(1S Suppl):243S-246S. (Review)
Progressive weight loss is a common feature of many types of cancer and is responsible not only for a poor quality of life and poor response to chemotherapy, but also a shorter survival time than is found in patients with comparable tumors without weight loss. Although anorexia is common, a decreased food intake alone is unable to account for the changes in body composition seen in cancer patients, and increasing nutrient intake is unable to reverse the wasting syndrome. Although energy expenditure is increased in some patients, cachexia can occur even with a normal energy expenditure. Various factors have been investigated as mediators of tissue wasting in cachexia. These include cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interferon-gamma (IFN-gamma) and leukemia inhibitory factor (LIF), as well as tumor-derived factors such as lipid mobilizing factor (LMF) and protein mobilizing factor (PMF), which can directly mobilize fatty acids and amino acids from adipose tissue and skeletal muscle respectively. Induction of lipolysis by the cytokines is thought to result from an inhibition of lipoprotein lipase (LPL), although clinical studies provide no evidence for an inhibition of LPL in the adipose tissue of cancer patients. Instead there is an increased expression of hormone sensitive lipase, the enzyme activated by LMF. Protein degradation in cachexia is associated with an increased activity of the ATP-ubiquitin-proteasome pathway. The biological activity of both the LMF and PMF was shown to be attenuated by eicosapentaenoic acid (EPA). Clinical studies show that this polyunsaturated fatty acid is able to stabilize the rate of weight loss and adipose tissue and muscle mass in cachectic patients with unresectable pancreatic cancer. Knowledge of the mechanism of cancer cachexia should lead to the development of new therapeutic agents.

Toft I, Bonaa KH, Ingebretsen OC, Nordoy A, Jenssen T. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. A randomized, controlled trial. Ann Intern Med. 1995 Dec 15;123(12):911-918.
Abstract: OBJECTIVE: To determine whether dietary supplementation with fish oil adversely affects glycemic control in patients with hypertension. DESIGN: Randomized, double-blind, placebo-controlled study. PATIENTS: 78 persons with untreated hypertension recruited from a population survey. INTERVENTION: Participants were randomly assigned to receive eicosapentaenoic and docosahexaenoic acids, 4 g/d, or corn oil placebo, 4 g/d, for 16 weeks. MEASUREMENTS: An oral glucose tolerance test; assessments of insulin release, glucose disposal, and insulin sensitivity done using the hyperglycemic clamp technique to keep plasma glucose levels at 10 mmol/L for 180 minutes; assessment of insulin sensitivity done using a euglycemic hyperinsulinemic clamp technique (infusing insulin and glucose to keep plasma glucose levels at 5 mmol/L); assessments of lipid levels and blood pressure. Measurements were done before and after intervention. RESULTS: Changes in integrated glucose and insulin response after the oral glucose challenge did not differ between the fish oil and corn oil groups after intervention (-0.6 +/- 0.7 compared with -1.0 +/- 0.6 mmol/L [P > 0.3] for integrated glucose and 143 +/- 76 compared with 169 +/- 84 pmol/L [P > 0.3] for insulin response). Changes in first-phase insulin release (34 +/- 72 pmol/L in the fish oil group compared with 191 +/- 112 pmol/L in the corn oil group [P > 0.3]), second-phase insulin release (179 +/- 66 pmol/L compared with 257 +/- 122 pmol/L [P > 0.3]), and insulin sensitivity index (-0.03 +/- 0.01 compared with -0.01 +/- 0.01 [mumol/kg.min divided by pmol/L]; P > 0.3) were also similar in both groups after treatment. Fish oil lowered systolic blood pressure by 3.8 mm Hg more than control (P = 0.04) and lowered diastolic blood pressure by 2.0 mm Hg more than control (P = 0.10). After fish oil treatment, triglyceride levels decreased by 0.28 +/- 0.08 mmol/L more than control (P = 0.01), and very-low-density lipoprotein cholesterol levels decreased by 0.13 +/- 0.04 mmol/L more than control (P = 0.01). CONCLUSION: Fish oil, in doses that reduce blood pressure and lipid levels in hypertensive persons, does not adversely affect glucose metabolism.

Wander RC, et al. alpha-Tocopherol influences in vivo indices of lipid peroxidation in postmenopausal women given fish oil. J Nutr. 1996 Mar;126(3):643-652.

Wander RC, Du S-H, Ketchum SO, Rowe KE. Effects of interaction of RRR-”-tocopheryl acetate and fish oil on low-density-lipoprotein oxidation in postmenopausal women with and without hormone-replacement therapy. Am J Clin Nutr. 1996 Feb;63(2):184-193.
Abstract: We evaluated the effects of RRR-alpha-tocpheryl acetate (alpha-tocopheryl acetate) and hormone-replacement therapy (HRT) on the oxidative susceptibility of low-density lipoprotein (LDL) in postmenopausal women consuming a fish oil supplement. The independent effect of fish oil was also assessed. Forty-eight women, equally divided between women using and not using HRT, participated in a double-blind crossover trial. Each of the four periods lasted 5 wk and was followed by a 4-wk washout interval. During each period all subjects were given a 15-g supplement of fish oil and either 0 (placebo), 100, 200, or 400 mg alpha-tocopheryl acetate daily. LDL resistance to oxidative modification was assessed by calculating lag time, propagation rate, and maximum production of conjugated dienes. Supplementation with fish oil and placebo shortened lag time and slowed propagation rate in women both using and not using HRT. After subjects consumed fish oil, supplementation with alpha-tocopheryl acetate increased plasma and LDL alpha-tocopherol contents significantly and lengthened lag time (at even the lowest concentration) but had no significant effect on propagation rate or maximum production compared with values measured after consumption of fish oil alone. Women not using HRT had faster propagation rates and higher maximum production than women using HRT; after supplementation with fish oil and alpha-tocopheryl acetate these differences prevailed. Supplements as low as 100 mg alpha-tocopheryl acetate/d increase the resistance of LDL to oxidation when fish oil supplements are used. HRT and fish oil supplements may independently affect LDL oxidative susceptibility.

Werbach MR. Foundations of Nutritional Medicine. Tarzana, CA: Third Line Press, 1997. (Review).

Wigmore SJ, Ross JA, Falconer JS, Plester CE, Tisdale MJ, Carter DC, Fearon KC. The effect of polyunsaturated fatty acids on the progress of cachexia in patients with pancreatic cancer. Nutrition 1996 Jan;12(1 Suppl):S27-30.
Abstract: Cachexia is common in patients with pancreatic cancer and has been associated with persistent activation of the hepatic acute phase response and increased energy expenditure. Fatty acids have been shown to have anticachectic effects in animal models and to reduce inflammatory mediators in healthy subjects and patients with chronic inflammatory disease. Eighteen patients with unresectable pancreatic cancer received dietary supplementation orally with fish oil capsules (1 g each) containing eicosapentaenoic acid 18% and docosahexaenoic acid 12%. Anthropometric measurement, body composition analysis, and measurement of resting energy expenditure and serum C-reactive protein were performed before and after supplementation with a median of 12 g/day of fish oil. Patients had a median weight loss of 2.9 kg/month (IQR 2-4.6) prior to supplementation. At a median of 3 months after commencement of fish oil supplementation, patients had a median weight gain of 0.3 kg/month (IQR 0-0.5) (p < 0.002). Changes in weight were accompanied by a temporary but significant reduction in acute phase protein production (p < 0.002) and by stabilisation of resting energy expenditure. This study suggests a component fish oil, perhaps EPA, merits further investigation in the treatment of cancer cachexia.

Zhu ZR, Agren J, Mannisto S, Pietinen P, Eskelinen M, Syrjanen K, Uusitupa M. Fatty acid composition of breast adipose tissue in breast cancer patients and patients with benign breast disease. Nutr Cancer 1995;24(2):151-160.
Abstract: Fatty acid composition of triglycerides (TGs) and phospholipids (PLs) in breast adipose tissue was analyzed in 73 female breast cancer patients and 55 patients with benign breast disease. No differences were observed in the dietary intake of the major fatty acids (i.e., palmitic, stearic, oleic, and linoleic acids) or in the proportion of TGs and PLs in breast adipose tissue between the two groups. In postmenopausal women, however, the dietary intake of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) was significantly lower in the breast cancer patients than in patients with benign breast disease. Accordingly, the percentage of docosahexaenoic acid of PLs in breast adipose tissue was significantly lower in breast cancer patients than in patients with benign breast disease among postmenopausal women. The stage of the breast cancer did not contribute to the observed alterations of fatty acid composition of PLs. Consonant with the previous epidemiologic data, the present results suggest that intake of the long-chain n-3 fatty acids (mainly derived from fish) may have a protective effect against breast cancer, particularly in postmenopausal women.