Omega-3 fatty acids have been making sensational nutritional headlines recently, which seems to be at odds with health news about fat intake. What are these fatty acids? Why are they “good?” How are they different from other fats? What foods contain them and how much should a person eat?
What are omega-3 fatty acids? All fats are made up of two compounds – glycerol and fatty acids. There are four fatty acid families, including omega-3 fatty acids.
This particular group has gained attention because of its unique role as the building blocks for linolenic acid, EPA and DHA – all very important for brain formation, eye retinal function and very specific body hormones. The human body is not able to synthesize its own omega-3 fatty acids, so it is important that they are part of everyone’s dietary intake.
Omega-3 fatty acids first gained attention when health researchers realized that the Eskimo Inuit tribes had lower rates of cardiac disease despite a diet high in whale fat. Follow-up studies identified omega-3 fatty acids in fatty fish as the protective factor. Other researchers studied omega-6 fatty acids, which appear to act, at least in part, as an adversary to omega-3 fatty acids.
This is an important discovery because it has become clear that the ratio of omega-3 to omega 6 may be very important in overall heart health. There are many good sources for omega-6 fatty acids – vegetable oils, seeds, nuts, and whole-grains – and almost everyone’s intake is more than enough.
How do you get omega-3 fatty acids?
Seafood, especially fatty fish like salmon and trout, is virtually the only source of any significant amount of omega-3 fatty acids, so eating fish regularly is a very important part of every diet plan.
Other fish like anchovies, oysters, tuna, sardines, mackerel, whitefish and herring are also good choices.
Crab, clams, halibut, perch, snapper, and cod contain less of these fatty acids, but enough that people who eat these fish often could easily meet their needs.
Flaxseed, walnuts, leaf greens vegetables and canola oil also provide omega-3 fatty acids, but not as much fatty fish do.
What is the bottom line?
Regular dietary inclusion of fish is recommended by health experts. Studies continue to show that eating fish twice a week makes a positive difference. Certainly, seafood is an overall healthy source of protein, low in saturated fat and therefore conducive to maintaining good cholesterol and blood pressure levels. Fish with bones – sardines and salmon – offer the added inducement of extra calcium in addition to their comparatively low cost and convenient availability in cans.
What about fish oil supplements? Any supplement poses the potential risk of shifting the balance of our body’s finely-tuned mechanics.
The various omega-3 studies have questioned the benefits of extra omega-3 fatty acids, partly because the balance between omega-3 and omega-6 must be maintained. Excessive amounts of omega-3 fatty acids may also increase the body’s susceptibility to free radical damage, which can lead to heart disease and adversely affect blood clotting, immune responses and diabetes.
For these powerful reasons, taking expensive omega-3 fatty acid supplements for cardiac health is not recommended. Instead, health experts say, two servings of fish per week, which represents an adequate amount, is a better alternative.
Omega-3 fatty acids have been shown to speed the rate of healing by patients with critical infections and burns. A large 13-year population study in Spain reported that eating even small amounts of fish provided protection against ovarian and digestive tract cancers.
Newer research suggests they may help reduce arthritic inflammation and pain, lessen the effects of asthma and lower blood pressure. At this point, the research is not definitive. Persons with arthritis, asthma, or high blood pressure should discuss with their doctor the wisdom of a trial period of omega-3 fatty acid supplements. Often, other treatments should be in place first.
By JoAnn Prophet, MS, RD, AICR
