The Health Benefits of Fish Oil (Omega-3 Fatty Acids)
Introduction & Biological Role
Omega-3 fatty acids (O3FA) are three specific polyunsaturated fats that have gained traction in recent years as a supplement. They are essential to normal metabolism in humans and, when supplemented, confer numerous health benefits. The physiologic effects of O3FA become evident after at least several weeks of consistent consumption as the body equilibrates them with other fatty acid stores.
The three specific types are α-linolenic acid (18:3, n−3; ALA), eicosapentaenoic acid (EPA, 20:5n-3), and docosahexaenoic acid (DHA, 22:6n-3); all of which are mostly found in fish. The omega-3 aspect of the name refers to when the first carbon-carbon double bond in the fatty acid chain begins. You may also hear this cluster of fatty acids referred to as long-chain n-3 polyunsaturated fatty acids (n-3 PUFA)
Fish Oil Supplement: http://amzn.to/2pW6jJq
Omega 3 Fatty Acid Supplements: http://amzn.to/2pcjI0W
Effects on Cardiovascular Risk Factors
Omega-3 fatty acid confer numerous benefits to reducing various cardiovascular risk factors. This includes (1) lower triglycerides 25-30% and a modest rise in HDL and LDL, (2) lowers BP, lowers systolic and diastolic, (3) lowers resting HR, and (4) improves cardiac muscle relaxation, filling and efficiency. Additionally, it may reduce the risk of arrhythmias. It also may increase bleeding time.
Regarding cardiovascular outcomes, O3FA reduces coronary heart disease (CHD) mortality, including risk of fatal MI and sudden cardiac death, in populations with and without established CHD. It reduces total mortality and lowers the incidence of heart failure. It may modestly reduce chronic progression of atherosclerosis. It is unknown at this time whether it reduces the risk of acute coronary syndrome. They may reduce the risk of developing a stroke as well as therapeutic value in those actively stroking, more studies are needed.
Effects on glucose metabolism, fat mass and obesity
O3FA appear to be associated with avery modest increase in blood glucose (2-6 mg/dL), however this not associated with increase in HbA1c. It may reduce risk of developing diabetes mellitus. It may also upregulate caloric expenditure in skeletal muscle and reduce the rate of weight gain in obesogenic patients. It does not appear to increase the bodies metabolic rate.
Muscle Mass and Hypertrophy
Omega-3 fatty acids (1) may augment muscle protein synthesis, although the mechanism is not well understood, (2) high doses increase glycogen resynthesis rates and glucose oxidation, (3) associated with increased ability of muscle cell to switch from glucose to fat for oxidation, and (4) may decrease rate of muscle degeneration.
Immunology and Inflammation
Omega-3 fatty acids appear to have some anti-inflammatory properties. They may suppress immune modulators including Interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP), and interleukin-6 (IL-6). They may inhibit cellular adhesion factors in white blood cells, proinflammatory factors from neutrophils, and T-cell activation
Neurologic and central nervous system effects.
Omega-3 fatty acids appear to modulate a variety of neurological effects. They may reduce aggression, stress, likely associated with reducing noradrenaline levels. They may improve memory in healthy individuals and decrease risk of depression (EPA > DHA), may have synergy with antidepressants. They increase cerebral blood flow in individuals with low dietary intake
Other organ systems
There is evidence to suggest Omega-3 fatty acids may also have the following effects on other organ systems: (1) may have a protective effect in developing diabetic nephropathy, (2) have protective effects against skin cancer development, (3) have a protective role in the symptoms of SLE and (4) may be protective effect against sunlight and sunburns.
Fish consumption during the prenatal and early postnatal periods appears to have modest beneficial effects on neurodevelopmental and cognitive outcome of offspring. However, fish may be contaminated by environmental pollutants, such as methylmercury. Women who may become pregnant, are currently pregnant, or breastfeeding consume one to two weekly servings of fish high in n-3 LCPUFA and low in mercury (avoid shark, swordfish, king mackerel, or tilefish because they contain high levels of mercury). Intake of one to two weekly servings of fish, preferably oily fish, achieves the DHA intake goal of 200 mg/day. Consumption may also be associated with reduced risk of complications and premature infant deaths, although more studies are needed.
Breastfeeding mothers should not eat shark, swordfish, king mackerel, or tilefish because they contain high concentrations of mercury. Breastfeeding mothers can eat up to 12 ounces a week (two average servings) of fish and shellfish that have lower concentrations of mercury. They include shrimp, canned light tuna, salmon, pollock, and catfish. Albacore (white) tuna has more mercury than canned light tuna, therefore, consumption of albacore tuna should be limited to 6 ounces (one average meal) per week. Check local advisories about the safety of fish caught by family and friends in local lakes, rivers, and coastal areas. If no advice is available, breastfeeding mothers may eat up to 6 ounces (one average meal) per week of fish caught from local waters, but do not consume any other fish during that week
But what about that study saying it increases your risk of prostate cancer?
I’m not going to dive into the details of the study, but Jim Stoppani wrote a pretty good article dismissing the conclusion that omega-3 fatty acids or fish oil increase your risk of prostate cancer. Although this one study may suggest a relationship, it is flawed and inconsistent with a plethora of other studies and population data suggesting otherwise.
Side Effects and safety
The number one side effect is gastrointestinal disturbances. There are mixed results for increased risk of bleeding and no significant risk for mercury; stick to supplements from Cod, sardines and mackeral.
The best dietary food sources include many types of fish (salmon, mackeral, cod, trout, and shrimp) as well as fish oil, flaxseed oil and krill oil supplements.