Omega-3 fatty acids, also known as n-3 polyunsaturated fatty acids or simply omega-3s, play a role in various body functions including cell division, blood clotting, digestion, fertility, the relaxation and contraction of muscles, and moving substances in and out of cells. Besides their traditional roles, research shows that omega-3s can prevent/manage certain ailments and diseases.
Studies show, when taken in appropriate doses, omega-3 fatty acids reduce various risk factors for cardiovascular disease, triglyceride levels, and blood pressure. Other, more recent, research shows that omega-3s may also help with some aspects of rheumatoid arthritis, arthritis, diabetes, asthma, inflammatory bowel disease, lupus, osteoporosis, and renal disease. More research, however is needed before any evidence can be considered conclusive.
Omega-3 fatty acids can be found in vegetable oils such as canola, flaxseed, and soybean oils; green leafy vegetables such as lettuce, broccoli, kale, and spinach; nuts; and beans. Fatty fish such as salmon, mackerel, herring, striped sea bass, and albacore tuna are also great sources.
These foods should be prepared in a healthy manner such as broiling or baking, versus frying which would cancel out any health benefits.
The American Heart Association recommends eating fatty fish at least two times per week and consuming plant-derived sources regularly.
In 2000, the US Food and Drug Administration announced a qualified health claim stating that dietary supplements containing omega-3 fatty acids reduced the risk of coronary heart disease.
Fish oil dietary supplements provide a convenient way of obtaining omega-3s outside of diet and, in fact, are the most commonly consumed nonvitamin/nonmineral product taken by adults.
The FDA recommends that healthy adults not exceed three grams per day of omega-3 fatty acids, with no more than two grams per day coming from a dietary supplement. Individuals with certain health conditions such as diabetes and blood disorders may be at risk for complications and should consult their health care providers before taking omega-3 supplements.
Doses for children have not been defined and supplements should not be given to children unless under a physician's orders.
Some common side effects reported with taking fish oil supplements include "fish burps," bad breath, heartburn, nausea, and loose stool. Freezing these supplements or taking them with meals may help reduce or eliminate these side effects.
Excessive amounts of omega-3s can lead to lowered immune function, gastrointestinal upset, diarrhea, bloody urine, heartburn, indigestion, abdominal bloating, excessive bleeding, and increased risk of stroke.
Certain species of fish contain harmful contaminants. Mercury, in particular, accumulates in fish meat more than the oil. Larger and older fish such as shark, king mackerel, tilefish, swordfish, and some larger tuna typically contain higher levels of Mercury and other pollutants than smaller and younger fish do.
Medications such as blood-thinners, cyclosporine, topical steroids, diabetes medications, or cholesterol- and blood pressure-lowering medications may interact or be dangerous when taken with omega-3 fatty acid supplements. Talk with your health care provider before taking any new supplements.
Mandy Seay is a bilingual registered and licensed dietitian who holds both a bachelor's degree in nutrition and in journalism. After gaining 30 pounds while living abroad, Mandy worked to lose the weight and regain her health. It was here that she discovered her passion for nutrition and went on to pursue a career as a dietitian. Mandy currently works as a nutrition consultant and freelance writer in Austin, Texas, where she specializes in diabetes, weight management and general and preventive nutrition. She recently published her first book, Your Best Health, a personalized program to losing weight and gaining a healthy lifestyle. Please visit Mandy's website at Nutritionistics.com.