Omega-3 fatty acid

Lore & Background

Since then, researchers have shown growing interest in unsaturated essential fatty acids as they form the framework for cell membranes. Awareness of health benefits dramatically increased since the 1980s. On 8 September 2004, the U.S. Food and Drug Administration gave 'qualified health claim' status to EPA and DHA omega-3 fatty acids, stating that 'supportive but not conclusive research shows that consumption of EPA and DHA [omega-3] fatty acids may reduce the risk of coronary heart disease.' The Canadian Food Inspection Agency permits a claim that DHA supports normal physical development of the brain, eyes, and nerves primarily in children under two years of age. Historically, whole food diets contained sufficient omega-3, but because omega-3 is readily oxidized, the trend toward shelf-stable processed foods has led to a deficiency in manufactured foods. Omega-3 fatty acid supplementation has limited evidence of benefit in preventing cancer, all-cause mortality, and most cardiovascular outcomes, although it modestly lowers blood pressure and reduces triglycerides.

Reader's Guide

Omega-3 fatty acids are essential polyunsaturated fats that humans cannot synthesize and must obtain from diet. They are critical for cell membrane structure and function, with DHA particularly abundant in the brain. The three physiologically important types are ALA (found in walnuts, chia seeds, flaxseeds, and hempseed oil), EPA, and DHA (found in fish, fish oils, and algae oil). Animals can convert ALA into EPA and DHA, but this ability may be impaired in aging. Despite widespread use, evidence for omega-3 supplementation in preventing cancer or cardiovascular disease is limited, though it modestly lowers blood pressure and triglycerides. The nomenclature derives from the location of the first double bond three carbons from the methyl end. Omega-3 fatty acids are vulnerable to oxidation, which has led to deficiencies in modern processed foods.

Did You Know?

• Omega-3 fatty acids are characterized by a double bond three atoms away from the terminal methyl group.
• The three types involved in human physiology are ALA, EPA, and DHA.
• Marine algae and phytoplankton are primary sources of omega-3 fatty acids.
• The FDA gave a qualified health claim to EPA and DHA in 2004 regarding reduced risk of coronary heart disease.