Fish oil consumption

Many studies have been conducted on marine fish oil consumption and relation to risk of breast or prostate cancer. The inhibition of eicosa-noids production from (B-6 PUFAs by higher consumption of fish oil with high levels of co-3 PUFAs, which is a common feature of lowering a cancer risk, was reported (Bagga et al, 1997 Terry et al, 2004). 

Fish/fish oil consumption has also been shown to affect plasma lipid and lipoprotein levels (for review, see Herold and Kinsella, 1986). The most consistent effect is a substantial reduction in plasma triglyceride following (0-3 fatty acid-rich diets. This is associated with reduced plasma VLDL since this lipoprotein fraction is the major carrier of triglyceride in the blood. The mechanism of this (o-3 fatty acid effect may involve inhibition of triglyceride synthesis in the liver, as well as a recluction in the formation of VLDL apoproteins (see Weaver and Holub, 1988). The effect of fish/fish oil feeding on plasma total cholesterol levels have been variable, with either no change or only a moderate decrease observed. Similarily, effects on LDL-cholesterol and HDL-cholesterol are variable. 

Hypertension. Prostaglandins appear to play a role in hypertension (elevated blood pressure). An increase in vasoconstrictor versus vasodilatory prostaglandins favors a rise in blood pressure (Smith and Dunn, 1985). Fish or fish oil consumption appears to cause a reduction in both systolic and diastolic blood pressure (see Weaver and Holub,... 

Herold, P.M. and Kinsella, J.E. (1986) Fish oil consumption and decreased risk of cardiovascular disease a comparison of findings from animal and human feeding trials. Am. J. Clin. Nutr. 43, 566-598. 

A USDA report indicates that between 1967 and 1988, butter consumption remained stable at 2 kg per capita, margarine dropped from 5.1 to 4.7 kg, and measured total fat intake per day dropped from 84.6 to 73.3 g (14). This study also projects that the reduced consumption of tropical oils is only temporary and will return to former use levels, possibly even higher. One reason for this projected rise in tropical oil consumption is the knowledge of the beneficial effects of medium-chain length acids high in lauric oils. There is a keen interest in omega-3 fatty acids, as well as linoleic acid, contained in fish oils. 

Consumption of fish oil in excess can generate immunotoxic effects in laboratory animals. Rats fed a 17% fish oil diet had reduced wound-healing responses when compared to com oil [59], In a mouse model of bacterial resistance to S. typhimurium, lower survival rates were reported for those animals that ingested a 20% fish oil diet over 15 days [59], Similar fish oil-induced effects in guinea pigs were noted in a study of experimental tuberculosis leading the authors to conclude that this treatment resulted in decreased resistance to infectious disease. The consumption of fish oil has also been reported to result in alterations of hemostatic parameters such as platelet production and function. However, there is no indication that at doses normally consumed by humans, immunotoxicity will occur. 

Although fish oils are used for human consumption, vegetable oils are more typically used in oral liquid dosage formulations. 

The safety of drugs containing EPA and DHA has been reviewed the reported adverse effects were similar to those in control groups (3). Even 3-7 g/day for several months did not change liver enzyme activities, and there were no bleeding problems. Consumption of fish oils reduces the resistance of LDL to oxidative modification, and this is partly opposed by the addition of vitamin E (4). Belching or eructation with a fishy taste or smell, vomiting, flatulence, diarrhea, and constipation are relatively common. 

In addition to fish oil, nutrigenomic studies have identified other possible modulators of TNF-a production and/or release in vitro. Kang et al. reported that soybean saponins suppressed the release of TNF-a by LPS-stimulated murine peritoneal macrophages.100 Horrigan et al. demonstrated that concentrations of caffeine that were relevant to human consumption consistently suppressed the production of TNF-a in human blood.101 Clearly, more studies that address the anti-inflammatory effects of food components in studies involving humans are warranted. 

Sidhu, K.S., 2003. Health benefits and potential risks related to consumption of fish or fish oil. Regul. Toxicol. Pharmacol. 38, 336-344. 

Covaci et al. (2007b) also studied BDEs in fish oil dietary supplements. Despite being taken daily, the authors concluded that their consumption did not significantly increase daily intakes of BDEs. The median daily intake from dietary supplements was 8 and 16 times lower than the intake from fish consumption alone or from a total diet, respectively. 

Kris- Etherton PM, Harris WS, Appel LJ. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Arterioscler. Thromb. Vase. Biol. 2003 23 e20. 

Prichard BNC, Smith CCT, Ling KLE, Betteridge DJ. Fish oils and cardiovascular disease. Br. Med. J. 1995 310 819-820. Kagawa Y, Nishizawa M, Suzuki M, et al. Eicosapolyenoic acids of serum lipids of Japanese islanders wifli low incidence of cardiovascular diseases. J. Nutr. Sci. Vitaminol. 1982 28 441-453. Kromhout D, Bosschieter EB, de Lezenne Coulander C. The inverse relation between fish consumption and 20-year mortality from coronary heart disease. N. Engl. J. Med. 1985 312 1205-1209. 

At low doses, PUFAs provide protection against coronary heart disease and reduce the severity of cardiac arrhythmias at high doses, they lower blood cholesterol and triglycerides, reduce platelet aggregation, have antithrombotic activity, and reduce blood viscosity. Several clinical studies have reported beneficial effects of supplementation on mortality, sudden death, and arrhythmias. In the Diet and Reinfarction Trial (DART), the use of fatty fish or fish oil led to a 29% reduction in mortality, and the GlSSI-Preven-zione trial showed that consumption of 1 g n-3-PUFA daily resulted in a 20% decrease in mortality and 45%i reduction in sudden death. ° ... 

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