Fish is a high-protein, low-fat food that provides a range of health benefits. Fish are high in omega -3 fatty acids, or the “good” fats. Since the human body can’t make significant amounts of these essential nutrients, fish are an important part of the diet. Omega -3 fatty acids have many health advantages and are listed below.
Several studies report possible anti-cancer effects of n−3 fatty acids (particularly breast, colon, and prostate cancer). Omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival. Among n-3 fatty acids [omega-3], neither long-chain nor short-chain forms were consistently associated with breast cancer risk. High levels of decosahexanoic acid, however, the most abundant n-3 PUFA in erythrocyte membranes, were associated with a reduced risk of breast cancer.
A 2007 systematic review of n-3 fatty acids and cachexia found evidence that oral n-3 fatty acid supplements benefit cancer patients, improving appetite, weight and quality pf life. A 2009 trial found that a supplement of eicosapentanoic acid helped cancer patients retain muscle mass.
In 1999, the GISSI-Prevenzione Investigators reported in the Lancet, the results of major clinical study in 11,324 patients with a recent myocardial infarction. Treatment 1 gram per day of n−3 fatty acids reduced the occurrence of death, cardiovascular death and sudden cardiac death by 20%, 30% and 45% respectively. These beneficial effects were seen from three months onwards. In 2006 by the American Journal of Clinical Nutrition indicated decreases in total mortality and cardiovascular incidents (i.e.myocardial infarctions ) associated with the regular consumption of fish and fish oil supplements.
In the March 2007 edition of the journal Atherosclerosis, 81 japanes men with unhealthy blood sugar levels were randomly assigned to receive 1800 mg daily of eicosapentanoic acid (EPA) with the other half being a control group. The thickness of the carotid arteries and certain measures of blood flow were measured before and after supplementation. This went on for approximately two years. A total of 60 patients (30 in the E-EPA group and 30 in the control group) completed the study. Those given the EPA had a statistically significant decrease in the thickness of the carotid arteries along with improvement in blood flow. The authors indicated that this was the first demonstration that administration of purified EPA improves the thickness of carotid arteries along with improving blood flow in patients with unhealthy blood sugar levels.
In a study published in the American Journal of Health System Pharmacy March 2007, patients with high triglycerides and poor coronary artery health were given 4 grams a day of a combination of EPA and DHA along with some monounsaturated fatty acids. Those patients with very unhealthy triglyceridet levels (above 500 mg/dl) reduced their triglycerides on average 45% and their VLDL cholesterol by more than 50%. VLDL is a bad type of cholesterol and elevated triglycerides can also be deleterious for cardiovascular health.
A study on the benefits of EPA published in The Lancet in March 2007, involved over 18,000 patients with unhealthy cholesterol levels. The patients were randomly assigned to receive either 1,800 mg a day of E-EPA with a statin drug or a statin drug alone. The trial went on for a total of five years. It was found at the end of the study those patients in the E-EPA group had superior cardiovascular function. Non-fatal coronary events were also significantly reduced in the E-EPA group. The authors concluded that EPA is a promising treatment for prevention of major coronary events, especially non-fatal coronary events. Similar to those who follow a Mediterranean diet, who consume high amounts of n−3 fatty acids from fatty fish - also tend to have higher proportions of n−3, increased HDL cholesterol and decreased triglycerides (fatty material that circulates in the blood) and less heart disease. Eating walnuts (the ratio of n−3 to n−6 is circa 1:4 respectively was reported to lower total cholestero by 4% relative to controls when people also ate 27% less cholesterol.
A study carried out involving 465 women showed serum levels of eicosapentanoic acid are inversely related to the levels of anti-oxidized-LDL antibodies. Oxidative modification of LDL is thought to play an important role in the development of atherosclerosis. A study shows that survivors of past myocardial infarctions are less likely to die from an arrhythmic event if they are consuming high levels of n-3. It is possible that these anti-arrhythmic effects are due to n-3 fatty acid’s ability to increase the fibrillation threshold of the heart tissue.
A study shows that n-3 fatty acids have mild anti-hypertensive effects. When subjects consumed n-3 from oily fish on a regular basis, their systolic blood pressure was lowered by about 3.5-5.5 mmHg.
In a study regarding fish oil published in the Journal of Nutrition in April 2007, sixty four healthy Danish infants from nine to twelve months of age received either cow's milk or infant formula alone or with fish oil. It was found that those infants supplemented with fish oil had improvement in immune function maturation with no apparent reduction in immune activation.
Limited evidence suggests that long-chain n-3 fatty acids delay or prevent the progression of certain psychotic disorders in high-risk children and adolescents. The evidence included the observation that individuals diagnosed with schizophrenia exhibited reduced levels of both n-6 and n-3 polyunsaturated fatty acids, and the results of a study in which the treatment of high-risk children with a dietary supplement containing both and eicosapentaenoate decosahexaenoate produced a statistically significant (95% confidence, but not 97.5% confidence) decrease in progression to schizophrenia.
Consumption of ethyl eicosapentaenoate (E-EPA) partially countered memory impairment in a rat model of Alzheimer’s disease and produced a statistically insignificant decrease in human depression.
Fish oil has been shown to have no effect on cognitive performance in older individuals (65 years of age or older) without dementia.
Current research suggests that the anti-inflammatory activity of long-chain n−3 fatty acids may translate into clinical effects. For example, there is evidence that rheumatoid arthritis sufferers taking long-chain n−3 fatty acids from sources such as fish have reduced pain compared to those receiving standard NSAIDs.