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Fish oil has shown initial promising results as an ingredient for joint health. A 12 month, double-blind, placebo-controlled study found that patients taking 2,600mg of omega-3 per day experienced less joint pain than those taking a placebo. Patients also reported less use of concomitant antirheumatic medications during the period of fish oil supplementation.
An in-vitro study in 2000 examined the molecular mechanisms by which omega-3s can affect inflammatory markers in cartilage. The study found that omega-3 fatty acids create a reduction in the expression and activity of aggrecanases, proteoglycan-degrading enzymes, the expression of inflammation-inducible cytokines interleukin (IL)-1alpha and tumor necrosis factor (TNF)-alpha, and cyclooxygenase (COX-2), but not the constitutively expressed cyclooxygenase COX-1.
The American Heart Association recommends that adults eat two servings of fish per week for beneficial omega-3’s. Individuals who do not eat fish, or don't often eat fish, would benefit from supplementation (1, 2).
Fatty fish is one of the best sources of omega-3 fatty acids, which are a major building block of the brain. Omega-3s play a role in sharpening memory and improving mood, as well as supporting cognitive performance.
Research suggests that DHA improves facets of memory and cognition and that greater consumption of omega-3 rich fish leads to better performance on cognitive battery tests (1).
In elderly adults, omega-3 intake has been associated with a slower rate of cognitive decline. Individuals who consumed two or more servings of fish per week were found to have 13% slower cognitive decline (2). Another study found that higher plasma levels of EPA in adults age 65 or older was associated with lower gray matter atrophy of the right hippocampal/parahippocampal area and of the right amygdala (3).
Research has indicated there may be a link between DHA levels and cognitive health and function. One study found participants in the lowest quartile of red blood cell DHA levels had smaller brain volume and greater white matter hyperintensity volume. Participants with lower DHA also had lower scores on tests of visual memory, executive function and abstract thinking models (4).
Similar results were found in another study of serum phospholipid levels. Higher DHA levels were associated with better performance on tests of nonverbal reasoning, and improved mental flexibility, working memory, and vocabulary on neuropsychological tests. EPA and ALA levels did not show any effect on cognitive performance (5).
DHA is a key component of all cell membranes and is found in abundance in the brain and eye (1). Very high levels of DHA are present in the retina, specifically in the disk membranes of the outer segments of photoreceptor cells (2).
In a randomized, double blind clinical trial sixty-four patients with dry eye symptoms between the ages of 45 and 90 years were randomized into 2 groups: 33 persons in the treatment group and 31 persons in the placebo group. The treatment group received 2 capsules of omega-3 fish oil (each containing 180 mg EPA and 120mg DHA) daily for 30 days, and the placebo group received 2 medium chain triglyceride oil capsules daily for 1 month. The study found that oral consumption of omega-3 fatty acids (180mg EPA and 120mg DHA twice daily for 30 days) is associated with a decrease in the rate of tear evaporation, an improvement in dry eye symptoms, and an increase in tear secretion (3).
The European Food Safety Authority concluded that a cause and effect relationship has been established between the consumption of DHA and the maintenance of normal vision (4).
Omega-3 from fish oil has been extensively researched for its benefits on the heart, with studies performed to assess its effects on cardiovascular disease, cholesterol and hypertension. In fact, the American Heart Association recommends eating fish, particularly fatty fish, at least two times per week. Fatty fish like salmon, mackerel, herring, lake trout, sardines and albacore tuna are high in omega-3 fatty acids. For more information about the research on omega-3 fatty acids for heart health, please see the links below: