Effect of fish oil on LDL oxidation and plasma homocysteine concentrations in health.
Piolot A, Blache D, Boulet L, Fortin LJ, Dubreuil D, Marcoux C, Davignon J, Lussier-Cacan S.
Hyperlipidemia and Atherosclerosis Research Group of the Clinical Research Institute of Montreal and INSERM-U498-Faculte de Medecine, Universite de Bourgogne, Dijon, Canada.
J Lab Clin Med 2003 Jan;141(1):41-9.

Oxidation of low-density lipoprotein (LDL) and hyperhomocysteinemia are believed to play a role in therogenesis. Whether n-3 polyunsaturated fatty acids increase LDL susceptibility to oxidation or influence homocysteine (Hcy) metabolism has long been a subject of controversy. In this study, we evaluated the effect of 8 weeks of dietary supplementation with 6 g/day of fish oil (FO; 3 g of n-3 fatty acids) on plasma lipoproteins, in vitro LDL peroxidation, antioxidant status, and plasma Hcy concentrations in 16 normolipidemic subjects. FO rapidly and significantly (P < .01) decreased plasma total and very low-density lipoprotein triglyceride concentrations and had no effect on LDL or high-density-lipoprotein cholesterol. The mean lag time before onset of Cu (2+)-induced LDL oxidation, as well as plasma and LDL alpha-tocopherol and beta-carotene concentrations, was unchanged. However, changes in plasma aminothiol concentrations occurred during the study. Specifically, a progressive and significant increase in total Hcy plasma concentrations was observed (13.4% and 20% after 4 and 8 weeks, respectively; P < .01). Total glutathione concentrations were significantly higher after 8 weeks (P < .05). The tHcy increase was not associated with changes in plasma folate or vitamin B (12) concentrations. However, concentrations of plasma nitric oxide metabolites (NO (x) = NO (2) + NO (3)) were significantly higher than at baseline after 8 weeks of FO intake (74%; P < .01). Further, the changes in total Hcy and NO (x) plasma concentrations observed after 8 weeks of FO were found to be significantly correlated (r = .78, P < .001). With this study, we report for the first time the apparent interaction of n-3 fatty acids and nitric oxide on Hcy metabolism.

Boreal freshwater fish diet modifies the plasma lipids and prostanoids and membrane fatty acids in man.
Agren JJ, Hanninen O, Laitinen M, Seppanen K, Bernhardt I, Fogelholm L, Herranen J, Penttila I.
Department of Physiology, University of Kuopio, Finland.
Lipids 1988 Oct;23(10):924-9.

The effect of fish diet on 43 healthy male students was studied. They ate a fish-containing meal for 15 weeks on an average of 3.7 times per week. Twenty-one of them voluntarily restricted their lipid intake while the rest ate normally. Controls continued their usual eating habits (19 students). The meals consisted of Finnish freshwater fish (87%) (vendace, pike, perch and rainbow trout) and brackish water fish (13%) (Baltic herring) that provided about 1 g of omega-3 polyunsaturated fatty acids per day (0.25 g eicosapentaenoic acid and 0.55 g docosahexaenoic acid). During the diet, omega-3 fatty acids increased in erythrocyte ghosts and platelets at the expense of omega-6 fatty acids. The concentration of serum cholesterol diminished in those fish consumers who lowered their lipid intake. Apolipoprotein A1 and B were lowered in both fish-consuming groups. Triglyceride levels also showed a tendency to decrease. The formation of thromboxane B2 during incubation of whole blood decreased in both fish-consuming groups. The decrease of plasma 6-keto-PGF1 alpha was not statistically significant, if compared with the controls. The results obtained indicate that a moderate intake of fish-containing meals has some beneficial effects on the plasma lipid and prostanoid metabolism, when coronary heart disease risk factors are considered.

Fish and long-chain omega-3 fatty acid intake and risk of coronary heart disease and total mortality in diabetic women.
Hu FB, Cho E, Rexrode KM, Albert CM, Manson JE.
Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave, Boston, Mass 02115, USA. frank.hu@channing.harvard.edu
Circulation 2003 Apr 15;107(14):1852-7.

BACKGROUND: Although several prospective cohort studies have found an inverse association between fish consumption and risk of coronary heart disease (CHD) or sudden cardiac death in the general population, limited data are available among diabetic patients. METHODS AND RESULTS: We examined prospectively the association between intake of fish and omega-3 fatty acids and risk of CHD and total mortality among 5103 female nurses with diagnosed type 2 diabetes but free of cardiovascular disease or cancer at baseline. Between 1980 and 1996 (45 845 person-years of follow-up), we documented 362 incident cases of CHD (141 CHD deaths and 221 nonfatal myocardial infarctions) and 468 deaths from all causes. Compared with women who seldom consumed fish (<1 serving/mo), the relative risks (RRs) (95% CI) of CHD adjusted for age, smoking, and other established coronary risk factors were 0.70 (0.48 to 1.03) for fish consumption 1 to 3 times per month, 0.60 (0.42 to 0.85) for once per week, 0.64 (0.42 to 0.99) for 2 to 4 times per week, and 0.36 (0.20 to 0.66) for 5 or more times per week (P for trend=0.002). Higher consumption of fish was also associated with a significantly lower total mortality (multivariate RR=0.48 [0.29 to 0.80] for > or =5 times per week [P for trend=0.005]). Higher consumption of long-chain omega-3 fatty acids was associated with a trend toward lower incidence of CHD (RR=0.69 [95% CI 0.47 to 1.03], P for trend=0.10) and total mortality (RR=0.63 [95% CI, 0.45 to 0.88], P for trend=0.02). CONCLUSIONS: A higher consumption of fish and long-chain omega-3 fatty acids was associated with a lower CHD incidence and total mortality among diabetic women.

Fish consumption and risk of sudden cardiac death.
Albert CM, Hennekens CH, O'Donnell CJ, Ajani UA, Carey VJ, Willett WC, Ruskin JN, Manson JE.
Department of Medicine, Brigham and Women's Hospital, Boston, MA 02215-1204, USA.
JAMA 1998 Jan 7;279(1):23-8.

CONTEXT: Dietary fish intake has been associated with a reduced risk of fatal cardiac end points, but not with nonfatal end points. Dietary fish intake may have a selective benefit on fatal arrhythmias and therefore sudden cardiac death. OBJECTIVE: To investigate prospectively the association between fish consumption and the risk of sudden cardiac death. DESIGN: Prospective cohort study. SETTING: The US Physicians' Health Study. PATIENTS: A total of 20 551 US male physicians 40 to 84 years of age and free of myocardial infarction, cerebrovascular disease, and cancer at baseline who completed an abbreviated, semiquantitative food frequency questionnaire on fish consumption and were then followed up to 11 years. MAIN OUTCOME MEASURE: Incidence of sudden cardiac death (death within 1 hour of symptom onset) as ascertained by hospital records and reports of next of kin. RESULTS: There were 133 sudden deaths over the course of the study. After controlling for age, randomized aspirin and beta carotene assignment, and coronary risk factors, dietary fish intake was associated with a reduced risk of sudden death, with an apparent threshold effect at a consumption level of 1 fish meal per week (P for trend=.03). For men who consumed fish at least once per week, the multivariate relative risk of sudden death was 0.48 (95% confidence interval, 0.24-0.96; P=.04) compared with men who consumed fish less than monthly. Estimated dietary n-3 fatty acid intake from seafood also was associated with a reduced risk of sudden death but without a significant trend across increasing categories of intake. Neither dietary fish consumption nor n-3 fatty acid intake was associated with a reduced risk of total myocardial infarction, nonsudden cardiac death, or total cardiovascular mortality. However, fish consumption was associated with a significantly reduced risk of total mortality. CONCLUSION: These prospective data suggest that consumption of fish at least once per week may reduce the risk of sudden cardiac death in men.

The role of seafood in foodborne diseases in the United States of America.
Lipp EK, Rose JB.
Department of Marine Sciences, University of South Florida, Saint Petersburg 33701, USA.
Rev Sci Tech 1997 Aug;16(2):620-40.

In the United States of America, seafood ranked third on the list of products which caused foodborne disease between 1983 and 1992. Outbreaks connected with fish vectors were caused by scombroid, ciguatoxin, bacteria and unknown agents; in shellfish, unknown agents, paralytic shellfish poisoning, Vibrio spp. and other bacteria, followed by hepatitis A virus, were responsible for the outbreaks. At least ten genera of bacterial pathogens have been implicated in seafood-borne diseases. Over the past twenty-five years, bacterial pathogens associated with faecal contamination have represented only 4% of the shellfish-associated outbreaks, while naturally occurring bacteria accounted for 20% of shellfish-related illnesses and 99% of the deaths. Most of these indigenous bacteria fall into the family Vibrionaceae which includes the genera Vibrio, Aeromonas and Plesiomonas. In general, Vibrio spp. are not associated with faecal contamination and therefore faecal indicators do not correlate with the presence of Vibrio. Viruses are the most significant cause of shellfish-associated disease: in New York State, for example, 33% and 62% of 196 outbreaks between 1981 and 1992 were caused by Norwalk virus and gastrointestinal viruses (small round structured viruses), respectively. In addition, several illnesses are a result of toxic algal blooms, the growth of naturally occurring bacteria and diatoms causing neurotoxic shellfish poisoning, paralytic shellfish poisoning, diarrhoetic shellfish poisoning, amnesic shellfish poisoning and ciguatera. Current estimates place the annual number of ciguatera cases at 20,000 worldwide. Scombroid poisoning is the most significant cause of illness associated with seafood. Scombrotoxin is of bacterial origin and halophilic Vibrio spp. causing high histamine levels are implicated as the source. Scombroid poisoning is geographically diverse and many species have been implicated, namely: tuna, mahi-mahi, bluefish, sardines, mackerel, amberjack and abalone. Temperature abuse has been cited as a major cause of scombroid poisoning. For routine work, the use of faecal indicators to predict the relative level of faecal contamination should not be disposed of. However, the main source of seafood illness is due to species which are not predicted by these organisms. In order to protect public health, routine surveillance using new pathogen-specific techniques such as polymerase chain reaction should be used. This, in combination with risk assessment methods and hazard analysis and critical control points, will begin to address the need for improvement in the safety of seafood.

Fish consumption and the 30-year risk of fatal myocardial infarction.
Daviglus ML, Stamler J, Orencia AJ, Dyer AR, Liu K, Greenland P, Walsh MK, Morris D, Shekelle RB.
Department of Preventive Medicine, Northwestern University Medical School, Chicago, IL 60611, USA.
N Engl J Med 1997 Apr 10;336(15):1046-53.

BACKGROUND: Epidemiologic data on the possible benefit of eating fish to reduce the risk of coronary heart disease have been inconsistent. We used data from the Chicago Western Electric Study to examine the relation between base-line fish consumption and the 30-year risk of death from coronary heart disease. METHODS: The study participants were 1822 men who were 40 to 55 years old and free of cardiovascular disease at base line. Fish consumption, as determined from a detailed dietary history, was stratified (0, 1 to 17, 18 to 34, and > or = 35 g per day). Mortality from coronary heart disease, ascertained from death certificates, was classified as death from myocardial infarction (sudden or nonsudden) or death from other coronary causes. RESULTS: During 47,153 person-years of follow-up, there were 430 deaths from coronary heart disease; 293 were due to myocardial infarctions (196 were sudden, 94 were nonsudden, and 3 were not classifiable). Cox proportional-hazards regression showed that for men who consumed 35 g or more of fish daily as compared with those who consumed none, the relative risks of death from coronary heart disease and from sudden or nonsudden myocardial infarction were 0.62 (95 percent confidence interval, 0.40 to 0.94) and 0.56 (95 percent confidence interval, 0.33 to 0.93), respectively, with a graded relation between the relative risks and the strata of fish consumption (P for trend = 0.04 and 0.02, respectively). These findings were accounted for by the relation of fish consumption to nonsudden death from myocardial infarction (relative risk, 0.33; 95 percent confidence interval, 0.12 to 0.91; P for trend= 0.007). CONCLUSIONS: These data show an inverse association between fish consumption and death from coronary heart disease, especially nonsudden death from myocardial infarction.

Fish consumption and risk of stroke in men.
He K, Rimm EB, Merchant A, Rosner BA, Stampfer MJ, Willett WC, Ascherio A.
Department of Nutrition, Harvard School of Public Health, 665 Huntington Ave, Boston, Mass 02115, USA.
JAMA 2002 Dec 25;288(24):3130-6.

CONTEXT: The effect of fish consumption or long-chain omega-3 polyunsaturated fatty acid (PUFA) intake on risk of stroke remains uncertain. OBJECTIVE: To examine the relation of fish consumption and long-chain omega-3 PUFA intake and risk of stroke in men. DESIGN AND SETTING: The Health Professional Follow-up Study, a US prospective cohort study with 12 years of follow-up. PARTICIPANTS: A total of 43 671 men aged 40 to 75 years who completed a detailed and validated semiquantitative food frequency questionnaire and who were free of cardiovascular disease at baseline in 1986. MAIN OUTCOME MEASURE: Relative risk (RR) of stroke by subtype based on cumulative average fish consumption or long-chain omega-3 PUFA intake, ascertained in 1986, 1990, and 1994. RESULTS: We documented 608 strokes during the 12-year follow-up period, including 377 ischemic, 106 hemorrhagic, and 125 unclassified strokes. Compared with men who consumed fish less than once per month, the multivariate RR of ischemic stroke was significantly lower among those who ate fish 1 to 3 times per month (RR, 0.57; 95% confidence interval [CI], 0.35-0.95). However, a higher frequency of fish intake was not associated with further risk reduction; the RR was 0.54 (95% CI, 0.31-0.94) for men who consumed fish 5 or more times per week. This lack of linearity was confirmed by spline analyses. By dichotomized fish intake, the multivariate RR for men who consumed fish at least once per month compared with those who ate fish less than once per month was 0.56 (95% CI, 0.38-0.83) for ischemic stroke and 1.36 (95% CI, 0.48-3.82) for hemorrhagic stroke. The inverse association between fish intake and risk of ischemic stroke was not materially modified by use of aspirin. No significant associations were found between fish or long-chain omega-3 PUFA intake and risk of hemorrhagic stroke. CONCLUSION: Our findings suggest that eating fish once per month or more can reduce the risk of ischemic stroke in men.

Fish and healthy pregnancy: more than just a red herring!
Rice R.
Fish Foundation, Devon.
Prof Care Mother Child 1996;6(6):171-3.

In modern Western diets we eat predominantly omega-6 essential fatty acids from vegetable oils, and too little omega-3. The Department of Health recommends doubling the amount of omega-3s we eat. Omega-3 essential fatty acids (EFAs) are derived mainly from fish oils. Omega-3s are believed to help reduce the risks of cardiovascular disease. Among the main materials required for fetal brain and CNS growth in late pregnancy are omega-3s (mainly docosahexaenoic acid [DHA]) and omega-6 EFAs (mainly arachidonic acid [AA]). These come from the mother's diet. Several formulae for preterm infants now contain DHA and AA to aid optimum brain, nerve and retinal development. One manufacturer has begun to include DHA and AA in formulae for term babies. Breast milk contains DHA and AA, derived from the mother's diet. Eating oily fish in pregnancy has been found to have a slight beneficial effect on birthweight and length of gestation. Eating fresh or canned oil-rich fish (e.g. kippers, herring, mackerel, salmon, sardine, pilchards, tuna) twice or three times a week can be encouraged as part of a healthy balanced diet, in pregnancy and for all the family. As well as containing omega-3 polyunsaturates, oily fish is a good source of protein and vitamins A and D. Alternatively, a fish-oil supplement may be taken. Cod liver oil is best avoided during pregnancy, because of concerns over the possible teratogenicity of vitamin A.

Cardiac benefits of fish consumption may depend on the type of fish meal consumed: the Cardiovascular Health Study.
Mozaffarian D, Lemaitre RN, Kuller LH, Burke GL, Tracy RP, Siscovick DS; Cardiovascular Health Study.
Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, Wash, USA.
Circulation 2003 Mar 18;107(10):1372-7.

BACKGROUND: Few studies have examined associations of fish consumption with ischemic heart disease (IHD) risk among older adults or how different types of fish meals relate to IHD risk. METHODS AND RESULTS: In a population-based prospective cohort study, usual fish consumption was ascertained at baseline among 3910 adults aged > or =65 years and free of known cardiovascular disease in 1989 and 1990. Consumption of tuna and other broiled or baked fish correlated with plasma phospholipid long-chain n-3 fatty acids, whereas consumption of fried fish or fish sandwiches (fish burgers) did not. Over 9.3 years' mean follow-up, there were 247 IHD deaths (including 148 arrhythmic deaths) and 363 incident nonfatal myocardial infarctions (MIs). After adjustment for potential confounders, consumption of tuna or other broiled or baked fish was associated with lower risk of total IHD death (P for trend=0.001) and arrhythmic IHD death (P=0.001) but not nonfatal MI (P=0.44), with 49% lower risk of total IHD death and 58% lower risk of arrhythmic IHD death among persons consuming tuna/other fish 3 or more times per week compared with less than once per month. In similar analyses, fried fish/fish sandwich consumption was not associated with lower risk of total IHD death, arrhythmic IHD death, or nonfatal MI but rather with trends toward higher risk. CONCLUSIONS: Among adults aged > or =65 years, modest consumption of tuna or other broiled or baked fish, but not fried fish or fish sandwiches, is associated with lower risk of IHD death, especially arrhythmic IHD death. Cardiac benefits of fish consumption may vary depending on the type of fish meal consumed.

Histamine poisoning associated with eating tuna burgers.
Becker K, Southwick K, Reardon J, Berg R, MacCormack JN.
Office of International and Refugee Health, US Department of Health and Human Services, 5600 Fishers Ln, Parklawn Bldg, Room 18-105, Rockville, MD 20857, USA.
JAMA 2001 Mar 14;285(10):1327-30.

CONTEXT: Histamine poisoning occurs when persons ingest fish in which bacteria have converted histidine to histamine, a process that usually can be controlled by storage at low temperatures. From 1994 to 1997, North Carolina averaged 2 cases annually; however, from July 1998 to February 1999, a total of 22 cases of histamine fish poisoning were reported. OBJECTIVES: To examine the increase in histamine case reports, identify risk factors for poisoning, and develop recommendations for prevention. DESIGN AND SETTING: Case series evaluated in North Carolina from July 1998 to February 1999. SUBJECTS: Reported case-patients with 2 of the following symptoms within 2 hours of eating tuna: rash, facial flushing, vomiting, diarrhea, dyspnea, a tight feeling in the throat, headache, or a metallic or peppery taste in the mouth. RESULTS: Twenty cases occurred during 5 outbreaks, and there were 2 single occurrences. Of the 22 persons affected, 19 (86%) sought emergency medical care. All case-patients ate tuna: 18 ate tuna burgers, 2 ate salad containing tuna, and 2 ate filets. Tuna samples (available from 3 outbreaks) had histamine levels above the Food and Drug Administration regulatory level of 50 ppm (levels were between 213 and 3245 ppm). In 19 cases, the tuna used to prepare burgers or salads was frozen and thawed more than once before serving. Violations of recommended temperature controls were identified in 2 of the 5 restaurants, accounting for 14 (64%) cases. CONCLUSIONS: Tuna burgers, a relatively new menu item in restaurants, were associated with an increase in histamine poisoning cases in North Carolina. Tuna ground for burgers can be susceptible to both temperature fluctuations and bacterial contamination.

A tuna fish diet influences cat behavior.
Houpt KA, Essick LA, Shaw EB, Alo DK, Gilmartin JE, Gutenmann WH, Littman CB, Lisk DJ.
Department of Physiology, Cornell University, New York State College of Veterinary Medicine, Ithaca.
J Toxicol Environ Health 1988;24(2):161-72.

When observed in their home cages, cats fed commercial tuna fish cat food were less active, vocalized less, and spent more time on the floor and more time eating than cats fed commercial beef cat food. There were no differences in response to human handling between the two groups. There were no differences in learning ability on a two-choice point maze or in reversal learning in the same maze between beef- and tuna-fed cats. The behavior of the groups differed in a 15-min open field test only in the number of toys contacted. Cats fed the tuna had elevated tissue levels of mercury and selenium.

Nutritional evaluation of solar dried sardines as a ruminant protein supplement.
Early RJ, Mahgoub O, Lu CD, Ritchie A, Al-Halhali AS, Annamalai K.
Department of Animal and Veterinary Sciences, College of Agriculture, Sultan Qaboos University, P.O. Box 34, PC 123, Al Khod, Oman.
0921-4488 2001 Jul;41(1):39-49.

Solar dried sardines of various qualities were analyzed for nutrient content and for nutrient digestibility and nitrogen balance in sheep. Additionally, key serum enzymes and metabolites were examined to identify potential toxic effects. Dried sardine protein, ether extract and crude ash content ranged from 65 to 39%, 5.7 to 5.1%, and 22 to 51%, respectively, for high to low quality dried sardines. Visual appraisal of the dried sardines did not appear to be very reliable for determining dried sardine quality. Crude protein content was highly correlated (r(2)=0.962) with crude ash content based on the following equation (dry matter basis): crude protein%=86.0 - (0.961xcrude ash%). Therefore, crude ash could be used to estimate crude protein content and dried sardine quality. Digestibility in Omani sheep was determined on diets composed of a composite of dried sardines collected from Al-Batinah region of the Sultanate (the average crude protein content was 51%) and compared to that of a similar diet using soybean meal (also 51% crude protein) as the major protein source. The digestibility of crude protein, ether extract, total carbohydrates, digestible energy and metabolizable energy in diets utilizing dried sardines versus the soybean meal diet were 74 versus 76%, 69 versus 68%, 67 versus 69%, 64 versus 66%, and 52 versus 56%, respectively. Although, protein digestibility was similar, nitrogen balance data suggested that nitrogen in the dried sardine diet was not as efficiently utilized as nitrogen in the soybean meal diet. Key serum enzymes and metabolites did not suggest that dried sardines at 10% of the total dietary intake would cause metabolic disturbances in sheep. The study suggests that solar dried sardines may be effectively used in ruminant diets but may not have the protein by-pass value of commercial, processed fish meals.

Therapeutic effect of lipids from the Far Eastern sardine (Sardinops sagax melanostica) in experimental hypercholesterolemia in rats.
Ivanova IL, Shchepin VA, Akulin VN.
Vopr Pitan 1986 Jul-Aug;(4):48-50.

Hypercholesterolemia was experimentally induced in rats which received diets with a high fat content (66% calories) and cholesterol loading (2.5% of ration). The therapeutic effect of lipids isolated from quick-frozen Far East sardines was tested on rats given 500 mg lipids daily. The content of the blood serum lipid fractions in the test animals decreased under the action of the sardines' lipids: the total cholesterol level dropped by 23%, beta-lipoprotein cholesterol by 29%, triglycerides by 15%; the content of beta-lipoproteins became normal. The blood coagulation time was diminished in rats receiving diets with a high content of fat and cholesterol, as compared to that in control animals; and it increased under the action of sardines' lipids. A conclusion has been made on the hypolipidemic property of Far East sardines' lipids that produce a therapeutic effect on the blood lipid metabolism in animals.

High dietary iron concentrations enhance the formation of cholesterol oxidation products in the liver of adult rats fed salmon oil with minimal effects on antioxidant status.
Brandsch C, Ringseis R, Eder K.
Institute of Nutritional Sciences, Martin-Luther-University of Halle-Wittenberg, Germany.
J Nutr 2002 Aug;132(8):2263-9.

The aim of this study was to investigate the effect of high dietary iron concentrations on the antioxidant status of rats fed two different types of fat. Four groups of male adult Sprague-Dawley rats were fed diets with adequate (50 mg iron supplemented per kg diet) or high (500 mg iron supplemented per kg diet) iron concentrations with either lard or salmon oil as dietary fat at 100 g/kg for 12 wk. The antioxidant status of the rats was profoundly influenced by the type of fat. Rats fed salmon oil diets had higher concentrations of thiobarbituric acid-reactive substances (TBARS) (P < 0.001), various cholesterol oxidation products (COP) (P < 0.001), total and oxidized glutathione (P < 0.05) and a lower concentration of alpha-tocopherol (P < 0.05) in liver and plasma than rats fed lard diets. The iron concentration of the diet did not influence the concentrations of TBARS, the activities of superoxide dismutase and glutathione peroxidase or the concentration of alpha-tocopherol in plasma or liver. The activity of catalase (P < 0.01) and the concentrations of total, oxidized and reduced glutathione (P < 0.05) in liver were slightly but significantly higher in rats fed high iron diets than in rats fed adequate iron diets, irrespective of the dietary fat. Rats fed the high iron diets with salmon oil, moreover, had higher concentrations of various COP in the liver (P < 0.001) than rats fed adequate iron diets with salmon oil. These results suggest that feeding a high iron diet does not generally affect the antioxidant status of rats but enhances the formation of COP, particularly if the diet is rich in polyunsaturated fatty acids.

PCB congener patterns in rats consuming diets containing Great Lakes salmon: analysis of fish, diets, and adipose tissue.
Jordan SA, Feeley MM.
Health Canada, Postal Locator 2204 D1, Tunney's Pasture, Ottawa, Ontario, K1A 0L2, Canada.
Environ Res 1999 Feb;80(2 Pt 2):S207-S212.

As part of a multidisciplinary toxicological investigation into Great Lakes contaminants, chinook salmon were collected from Lake Huron (LH) and Lake Ontario (LO) and incorporated (as lyophilized fillets) into standard rat diets as 20 or 100% of the protein complement (5 or 20%, w/w diet-LH5, LH20, LO5, and LO20 diets). Final PCB concentrations in the experiment ranged from 3.15 ng/g in the control diet to 1080 ng/g in the high-dose (20%) LO diet, with maximal estimated daily consumption by the rats of 82microg PCBs/kg body wt in the LO20 dietary group. Seventeen PCB congeners, PCB 85, 99, 101, 105, 110, 118, 128, 129, 132, 138, 149, 153, 170, 177, 180, 187, and 199, occurred at >/=3.0% of the total PCBs in the fish with no major site differences. Cumulatively, these 17 congeners accounted for up to 75% of the total PCBs in the fish compared to 44 and 54% in two commercial Aroclors, 1254 and 1260, respectively. PCB 77 was the major "dioxin-like" congener in the fish, followed by PCB 126 and then PCB 169. All major dietary congeners bioaccumulated in the adipose tissue of the rats with the exception of PCB congeners 101, 110, 132, and 149. The group of 17 major congeners accounted for up to 71% of the total PCBs in adipose tissue samples collected from the rats following up to 19 weeks of diet ingestion. Of the coplanar PCB congeners, PCB 77 appeared to bioaccumulate to a lesser extent compared to PCBs 126 and 169. When comparing PCBs in the rat adipose tissue to PCB congeners in Canadian breast milk, PCBs 44, 49, 74, and 137 tended to occur in higher amounts in the human samples (contributing together 18.4 vs. 1.4% of the total PCB concentration), whereas PCB 129 occurred at higher levels in the rats (3.4 vs. 0.3% of the total PCB concentration, respectively). Although adipose tissue from the rats fed diets containing Great Lakes salmon had up to two orders of magnitude higher concentrations of PCBs compared to average human values, with the exception of some lower chlorinated congeners, similar major congeners tended to be present in both the rats in the present study and humans.

The hypercholesterolemic effect of cod protein is reduced in the presence of high dietary calcium.
Jacques H, Lavigne C, Desrosiers T, Giroux I, Hurley C.
Departement de nutrition humaine et de consommation, Universite Laval, Quebec, Canada.
Can J Physiol Pharmacol 1995 Apr;73(4):465-73.

To determine the respective and interactive effects of dietary protein source and calcium level on serum, hepatic, and fecal lipid levels, 48 male New Zealand rabbits were fed purified diets varying in the source of dietary protein, namely casein, cod protein, or soy protein, at an adequate (7 mg Ca/g diet) or a high (14 mg Ca/g diet) concentration of calcium in a 3 x 2 factorial design for 28 days. Dietary proteins interacted with dietary calcium to modulate serum and low density lipoprotein (LDL) cholesterol. When combined with the adequate-calcium diet, code protein induced higher levels of serum and LDL cholesterol than casein and soy protein, induced lower serum and LDL cholesterol than when associated with an adequate concentration of calcium. These results indicate that the hypercholesterolemic effect of cod protein is reduced in the presence of high dietary calcium. Moreover, fecal lipid content was inversely correlated with serum total (p = 0.06) and LDL (p = 0.04) cholesterol in rabbits fed cod protein diets only. An increased formation of insoluble calcium phosphate in the intestine, which may result in lower fat intestinal absorption and serum cholesterol levels, may have been responsible for the decrease in serum and LDL cholesterol in rabbits fed cod protein with high dietary calcium.

Cod protein lowers the hepatic triglyceride secretion rate in rats.
Demonty I, Deshaies Y, Lamarche B, Jacques H.
Human Nutrition Research Group, Department of Food Science and Nutrition. Department of Anatomy and Physiology and. The Nutraceutical and Functional Food Institute, Laval University, Quebec, QC G1K 7P4 Canada.
J Nutr 2003 May;133(5):1398-402.

The objective of the present study was to determine the combined effects of cod protein and fish oil on the modulation of triglyceride metabolism in rats, and to evaluate their potential mechanisms of action. Plasma and hepatic lipid concentrations, triglyceride (TG) secretion rates and postheparin plasma lipoprotein lipase (LPL) activity were determined in rats fed for 28 d diets varying in both protein (200 g/kg) and lipid (140 g/kg) sources: 1) casein-menhaden oil, 2) casein-beef tallow, 3) cod protein-menhaden oil or 4) cod protein-beef tallow. Menhaden oil feeding diminished hepatic TG concentrations (P = 0.02), hepatic TG secretion rates (P = 0.003) and triglyceridemia (P = 0.02) compared with beef tallow. Hepatic TG concentrations (P = 0.05) and TG secretion rates (P = 0.04) were reduced in rats fed cod protein compared with those fed casein. The protein source did not exert an independent effect on triglyceridemia, whereas the combination of cod protein and menhaden oil resulted in 50% lower plasma TG compared with the casein-beef tallow mixture, whereas the combination of menhaden oil and casein did not significantly decrease triglyceridemia compared with casein-beef tallow. Menhaden oil (P = 0.005) and cod protein (P = 0.03) also lowered plasma cholesterol concentrations in comparison with beef tallow and casein, respectively. This was associated with a reduction in hepatic cholesterol concentrations when rats fed cod protein were compared with those fed casein (P = 0.006). No diet effect was observed on postheparin plasma LPL activity, but the activity of hepatic triglyceride lipase was reduced in rats fed menhaden oil compared with those fed beef tallow. These findings show that both cod protein and menhaden oil exert independent and beneficial effects on lipid metabolism in rats.

Surimi and native codfish contain a common allergen identified as a 63-kDa protein.
Mata E, Favier C, Moneret-Vautrin DA, Nicolas JP, Han Ching L, Gueant JL.
Laboratoire de Biochimie Nutritionnelle, INSERM U 308, Faculte de Medicine de Nancy, France.
Allergy 1994 Jul;49(6):442-7.

We have compared the allergenicity of codfish and surimi (prepared from codfish) by skin testing, specific IgE-RIA, and leukocyte histamine release (LHR) in six fish-allergic patients. Prick tests were positive for codfish and, to a lesser extent, surimi. The percentages of labeled anti-IgE bound to surimi-Sepharose were 1.55 +/- 0.19% and 3-6% with control and patient sera, respectively. Inhibition of the surimi protein-Sepharose IgE-RIA was greatest (80%) at protein concentrations of 13.4 and 408.5 micrograms/ml for codfish and surimi extract, respectively. The allergenic protein was isolated by gel filtration and subjected to SDS-PAGE. The eluate from codfish contained several proteins ranging from 13 to 63 kDa, while the eluate from surimi contained a single 63-kDa protein. It was concluded that surimi contained a single allergenic protein.

Acute allergic reactions to Anisakis simplex after ingestion of anchovies.
Foti C, Nettis E, Cassano N, Di Mundo I, Vena GA.
Department of Internal Medicine, Immunology and Infectious Diseases, University of Bari, Italy.
Acta Derm Venereol 2002;82(2):121-3.

Anisakis simplex is a seafish nematode, which is responsible for the well-known human infection (anisakiasis) and can induce IgE-mediated reactions. IgE sensitization to Anisakis simplex can be frequent in particular countries and should be suspected in patients with acute allergic symptoms after ingestion of fish. The etiological role of Anisakis simplex was evaluated in 49 adult subjects with acute allergic symptoms after ingestion of anchovies. Serum-specific IgE and prick tests to anchovy were negative in each patient. Specific IgE reactions to Anisakis were positive in 45 patients and skin tests in 43. Only 3 patients with allergy to the nematode were atopic. However, IgE responses to Anisakis were also observed in habitual consumers of raw fish, without any clinical manifestations, suggesting that the relevance of results of conventional tests has to be interpreted on the basis of clinical aspects.

Evolution of histidine decarboxylase bacterial groups during the ripening of Spanish semi-preserved anchovies.
Rodriguez-Jerez JJ, Lopez-Sabater EI, Roig-Sagues AX, Mora-Ventura MT.
Higiene e Inspeccion de los Alimentos, Facultad de Veterinaria, Universidad Autonoma de Barcelona, Bellaterra, Spain.
Zentralbl Veterinarmed B 1993 Oct;40(8):533-43.

We have studied the count evolutions of total aerobic mesophilic microorganisms, psychotrophic microorganisms, enterobacteria, faecal coliforms, sulphite-reducing bacteria and vibrio in spanish semi-preserved anchovies. These microorganisms are a sanitary index of the product and may produce high concentrations of histamine in both fresh and processed fish. The influence of NaCl concentration, redox potential, oxygen concentration and pH on bacterial growth have also been studied. With the exception of the sulphite-reducers and vibrio, the counts of the different bacterial groups decreased during the first two weeks of ripening, but later stabilized. The faecal coliforms did not appear in the culture media after these first two weeks, and the enterobacteria, what initially did not appear after first two weeks too, are detected at final phases probably for the final manipulation of elaboration processes. The count of the sulfite-reducers remained unchanged during the whole ripening process. Vibrio were not detected in any of the samples studied. NaCl and oxygen concentrations were the main factors influencing the decreasing bacterial counts. According to our results, the accumulation of high histamine concentrations in salted fish could be due to poor quality of the raw material, to inadequate handling or to other causes during its shelf life. The relationship with the histamine activity is probably due more to the presence of the halophilic or halotolerant microorganisms.

Recovery of functional proteins from herring (Clupea harengus) light muscle by an acid or alkaline solubilization process.
Undeland I, Kelleher SD, Hultin HO.
Department of Food Science, Chalmers University of Technology, and SIK-The Swedish Institute for Food and Biotechnology, P.O. Box 5401, S-402 29 Goteborg, Sweden.
J Agric Food Chem 2002 Dec 4;50(25):7371-9.

Proteins from herring (Clupea harengus) light muscle were extracted using acidic or alkaline solubilization; 92 and 89% of the initial muscle proteins were solubilized at pH 2.7 and 10.8, respectively, of which 96 and 94% were recovered during precipitation at pH 5.5. Consistency of the pH-adjusted muscle homogenates increased with increased raw material age and homogenization intensity; it declined following holding on ice. Some hydrolytic myofibrillar protein degradation occurred during cold storage of the acidified (pH 2.7) homogenates. With alkalized homogenates, hydrolysis was negligible. The total lipid content changed from 0.13 g/g of protein in the muscle to 0.04 g/g of protein in both the acid- and alkali-produced protein isolates. Corresponding values for the phospholipid content were from 0.037 to 0.02 g/g of proteins. Acid- and alkali-produced proteins made gels with equal strain and color. Stress values were equal or lower in acid- versus alkali-produced protein gels. When ice-stored raw material was used, strain and stress values of gels were reduced.

Specific probiotic characterization of Weissella hellenica DS-12 isolated from flounder intestine.
Cai Y, Benno Y, Nakase T, Oh TK.
Japan Collection of Microorganisms, The Institute of Physical and Chemical Research (RIKEN), Wako 351-0198, Japan.
J Gen Appl Microbiol 1998 Oct;44(5):311-316.

A total of 199 microorganisms were isolated from the intestinal contents of flounder (Paralichthys olivaceus) in a fish farm in Seoul, Korea. Among these strains, DS-12 was selected as a candidate for flounder probiotics because of its excellent exhibition of antimicrobial activity against fish pathogens such as edwardsiella, pasteurella, aeromonas, and vibrio, and initiate growth in 10% NaCl, 10% bile, and in broth at pH 3 for 90 min. This strain was Gram-positive, and catalase-negative coccoid rods that produced gas from glucose and formed more than 90% of lactate as the D(-) isomer. This organism is positioned at a cluster in the genus Weissella on the phylogenetic tree based on 16S rRNA sequences, which were assigned to Weissella hellenica on the basis of DNA-DNA relatedness. However, the type strain of W. hellenica JCM 10103(T) had no antibacterial activity against the fish pathogenic bacteria and was found to be quite different from the DS-12 strain in some sugar fermentation patterns of alpha-methyl-D-glucoside, esculine, cellobiose, melibiose, D-raffinose, and D-turanose, being especially unable to grow at 15 and 35 degrees C in 7% NaCl and 10% bile. The results obtained in the present study demonstrated that the type strain of W. hellenica had no probiotic characteristics, but the strain DS-12 could be used as a specific probiotic for flounder.

Development of a time-resolved fluoroimmunoassay for insulins and its application to monitoring of insulin secretion induced by feeding in the barfin flounder, Verasper moseri.
Andoh T, Nagasawa H.
Hokkaido National Fisheries Research Institute, 116 Katsurakoi, Kushiro 085-0802, Japan.
Gen Comp Endocrinol 2002 Feb 15;125(3):365-74.

A time-resolved fluoroimmunoassay (TR-FIA) system was developed to quantify insulin levels in the barfin flounder. This TR-FIA system is a solid-phase assay based on competition of unlabeled insulins and biotinylated barfin flounder insulin-II against an anti-barfin flounder insulin-II antibody. The minimum detectable level of barfin flounder insulin-I and -II in this TR-FIA was 10 pg/well which corresponded to 1.0 ng/ml, and insulin-II showed slightly higher crossreactivity than insulin-I. The accuracy of this TR-FIA was assured by specificity test, validation test, and recovery test using plasma added insulin-II. The results indicated the high specificity and sufficient accuracy of this assay system for insulin level measurement. This system was applied to the measurement of plasma insulin levels of fed and fasted barfin flounders. Plasma insulin levels (average +/- SEM) in fed flounders reached a maximum 2 h (9.3 +/- 1.7 ng/ml) and decreased gradually thereafter, while those in fasted flounders remained at low levels (1.1 +/- 0.1-2.0 +/- 0.2 ng/ml) during the experiment. After removing proteins by acidification and subsequent gel filtration, plasma samples taken from fed and fasted flounders at 2 h after feeding were fractionated separately by reversed-phase HPLC. In fed flounders, insulin immunoreactivity was detected in fractions corresponding to those of insulin-I or -II. The ratio of integrated insulin immunoreactivities of each peak was 0.378 +/- 0.044 (average +/- SD). This value was in good agreement with those (0.355 +/- 0.019) of absorbance areas of each insulin from Brockmann body extracts of the barfin flounder on reversed-phase HPLC. In fasted flounders, very weak insulin immunoreactivities were observed at retention times corresponding to those of insulin-I and -II. These results indicated that both insulin-I and -II were secreted into the blood being induced by feeding stimulation with approximately the same ratio as that of the quantities harbored in the Brockmann body. (C)2002 Elsevier Science (USA).

Fatty acid composition of commercially manufactured omega-3 enriched pork products, haddock, and mackerel.
Specht-Overholt S, Romans JR, Marchello MJ, Izard RS, Crews MG, Simon DM, Costello WJ, Evenson PD.
Department of Animal and Range Sciences, South Dakota State University, Brookings 57007-0392, USA.
J Anim Sci 1997 Sep;75(9):2335-43.

This study was conducted to determine the commercial feasibility of feeding a 15% ground flaxseed diet to finishing hogs for up to 42 d before slaughter and to compare the fatty acid composition of the resulting pork products with commercially produced haddock and mackerel. Eighty-seven pigs were fed a control diet (predominantly corn, soybean meal-based) and then a similar diet containing 15% flaxseed for the last 28 (FS28) or 42 d (FS42) before slaughter. Control pigs were continued on the control diet (CO28 and CO42). Percentages of saturated and monounsaturated fatty acids were decreased (P < .0001), and percentages of polyunsaturated fatty acids, most prominently alpha-linolenic acid [18:3(n-3)] and the sum of all (sigma) measured (n-3) fatty acids, were increased (P < .0001) in all pork tissues (backfat, liver, and longissimus thoracis) and products (lard, muffins, Braunschweiger, and bacon) due to dietary flaxseed. The percentage of arachidonic acid [20:4(n-6)] decreased in FS28 compared to CO28 liver (P < .0001) and in longissimus thoracis polar fraction FS42 compared to CO42. The percentage of 18:3(n-3) was similar in mackerel, CO bacon, and CO longissimus thoracis, and the percentage of 18:3(n-3) and sigma(n-3) in haddock was similar to that in FS bacon and FS longissimus thoracis. The percentage of 20:5 in FS42 longissimus thoracis, polar fraction, approached the level in haddock, but the percentages of 20:5 and 22:6 were greater (P < .0001) in mackerel than in haddock. The percentage of sigma(n-3) was greater (P < .0001) in mackerel than in haddock and sigma(n-6) was greater (P < .0001) in haddock than in mackerel. Commercial production of omega-3 enriched pork products can provide consumers a feasible alternative to a diet higher in fish than that normally consumed.

Bluefish-associated scombroid poisoning. An example of the expanding spectrum of food poisoning from seafood.
Etkind P, Wilson ME, Gallagher K, Cournoyer J.
Division of Communicable Disease Control, Commonwealth of Massachusetts Department of Public Health, Jamaica Plain 02130.
JAMA 1987 Dec 18;258(23):3409-10.

Five persons who attended a medical conference developed symptoms suggestive of an intoxication after a common meal. Although the symptoms were recognized as typical of scombroid poisoning, no fish of the Scrombridae family had been served. However, food histories implicated bluefish (Pomatomus saltatrix). The initially frozen bluefish had been improperly handled in storage and thawing. Elevated levels of histamine, putrescine, and cadaverine were detected in uncooked samples. This outbreak emphasizes that scombroid-type poisoning (1) can be caused by nonscombroid fish such as bluefish, (2) is probably more common than currently recognized, and (3) may become even more widespread as fish become a larger part of our diet. Physicians who work in conjunction with public health officials can help prevent additional cases and outbreaks.

Red drum Sciaenops ocellatus mortalities associated with Streptococcus iniae infection.
Eldar A, Perl S, Frelier PF, Bercovier H.
Department of Poultry and Fish Diseases, Kimron Veterinary Institute, Bet Dagan, Israel.
Dis Aquat Organ 1999 May 12;36(2):121-7.

We isolated for the first time Streptococcus iniae strains associated with diseased marine fish. Diseased red drum Sciaenops ocellatus were lethargic, and presented external signs (exophthalmia and loss of orientation) resembling those of freshwater fish infected by S. iniae. Skin lesions, extending to a necrotizing myositis, were typical of S. iniae infection of red drum. Histopathological findings indicate that S. iniae infection in red drum produces a chronic disease with systemic involvement characterized by multiple necrotic foci. Molecular epidemiology (RFLP [restriction fragment length polymorphism] ribotyping) revealed that 2 different ribotypes were involved in a single outbreak. The first is the EcoRI 'Israeli' trout and tilapine ribotype (Hind III type a strains), while the second is the EcoRI 'American' ribotype (Hind III type b strains), typical of tilapines farmed in Texas and Idaho.

Monospecific allergy to swordfish.
Kelso JM, Jones RT, Yunginger JW.
Department of Internal Medicine (Allergy Division), Naval Medical Center, San Diego, California, USA.
Ann Allergy Asthma Immunol 1996 Sep;77(3):227-8.

BACKGROUND: Fish allergy is a relatively common and potentially fatal condition. Most fish allergic subjects are allergic to multiple fish species. We encountered a patient clinically allergic only to swordfish. OBJECTIVE: To characterize the in vivo and in vitro IgE antibody responsiveness of this patient solely allergic to swordfish. METHODS: Prick skin tests, as well as immunoassay and protein immunoblotting for IgE antibody were performed using commercial fish extracts and fresh swordfish. A more typical multiple fish-allergic subject and a subject not allergic to food were also studied for comparison. RESULTS: The multiple fish-allergic subject demonstrated IgE antibody to a 13-kD protein in all fish tested (probably Gad c 1 and its analogues in other fish). The swordfish-allergic subject did not recognize this 13-kD band but did demonstrate IgE directed against a 25-kD band only in swordfish. The negative control showed no IgE binding to either the 13 or 25 kD bands. CONCLUSIONS: It is possible to be allergic to a single fish species, such as swordfish, and such monospecific allergy may be due to the presence of species-specific allergens, in this case a 25-kD allergen in swordfish.

A spermine-coupled cholesterol metabolite from the shark with potent appetite suppressant and antidiabetic properties.
Zasloff M, Williams JI, Chen Q, Anderson M, Maeder T, Holroyd K, Jones S, Kinney W, Cheshire K, McLane M.
Magainin Pharmaceuticals, Plymouth Meeting, Pennsylvania 19462, USA.
Int J Obes Relat Metab Disord 2001 May;25(5):689-97.

OBJECTIVE: We describe the pharmacological properties of a novel spermine-cholesterol adduct, MSI 1436 (3beta-N-1(spermine)-7alpha, 24R-dihydroxy-5alpha-cholestane 24-sulfate), which causes reversible suppression of food and fluid intake in mammals resulting in profound weight loss, not associated with other signs or symptoms of illness, and which exhibits antidiabetic properties in genetically obese mice. METHODS: Wild-type rodents and strains with genetic obesity were studied. Effects on food and fluid intake, body weight and composition were examined along with pharmacological and toxicological parameters. RESULTS: MSI-1436 induces profound inhibition of food and fluid intake in rats and mice, resulting in significant weight loss. MSI-1436 is active when introduced directly into the third ventricle of the rat, suggesting the compound acts on central targets. Pair-feeding studies suggest that MSI-1436 causes weight loss by suppressing food intake. Fluid intake is also profoundly reduced but animals remain normally