Omega-3 and omega-6 fats are both essential polyunsaturated fats that you need to get from your diet. While they have a similar chemical structure -- they both contain double bonds, a defining characteristic of unsaturated fats -- they differ enough to have their own specific physiological functions in your body.
Potential Health Effects
Both omega-3 and omega-6 fats are necessary for forming cell membranes and play a role in blood pressure control and inflammation. Omega-3 fats may help keep your heart healthier by lowering triglycerides and blood pressure and decreasing clogging of the arteries, blood clots and irregular heartbeat. Preliminary evidence shows omega-3 fats may also help limit the risk for rheumatoid arthritis and Alzheimer's disease, according to Colorado State University Extension.
According to the World Health Organization, total combined omega-3 and omega-6 intake should be between 6 percent and 11 percent of your caloric intake, and you need at least 2.5 percent to 3.5 percent of your calories to come from these fats to avoid deficiency symptoms. Omega-6 fats, including linoleic acid, should make up 2.5 percent to 9 percent of your calories, and omega-3 fats should make up at least 0.5 percent to 2 percent of your calories.
Of the omega-3 fats, between 0.25 and 2 grams per day should come from eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA, and at least 0.5 percent of calories should come from alpha-linolenic acid. EPA and DHA are found mainly in seafood and are the omega-3 fats your body can use the best. Your body can convert ALA to DHA and EPA, but the conversion isn't very efficient.
Potential for Deficiency
Most people get more omega-6 fats than they need in their diet, so an omega-6 deficiency isn't likely. Although people don't always get the recommended amount of omega-3 fats, an outright deficiency isn't common and mainly occurs in people who receive all their nutrients through feeding tubes, those with a fat absorption problem and people with cystic fibrosis. Symptoms include dermatitis and problems with vision and nerve function.
Because omega-3 fats can decrease inflammation and some types of omega-6 fats increase inflammation, a ratio of omega-6 to omega-3 fats of between 2-to-1 and 4-to-1 is recommended by the University of Maryland Medical Center. A study published in "Experimental Biology and Medicine" in June 2008 found that a low omega-6 to omega-3 ratio such as this may decrease your risk for heart disease, cancer, rheumatoid arthritis and other inflammatory and autoimmune diseases. That said, the European Food Information Council notes that increasing omega-3 fats may be more important than decreasing omega-6 fats, as simply trying to achieve the right ratio could result in an inadequate intake of both types of essential fats.
Balancing Your Intake
Trading cooking oils high in omega-6 fats for those that contain some omega-3 fats can help balance your intake. Limit grapeseed oil, corn oil, soybean oil and wheat germ oil, and use canola, hemp, pumpkin seed, walnut or flaxseed oil instead. You could also use olive oil, which consists of mostly monounsaturated fats.
Eating more foods with a high ratio of omega-3 fats to omega-6 fats -- such as seafood, mungo beans, kidney beans, navy beans, pinto beans and some fruits and vegetables -- can help you get more omega-3 fats while limiting your omega-6 consumption.
The foods that tend to provide the most omega-6 fats in a typical American diet include chicken dishes, grain-based desserts, salad dressing, pizza, chips, bread, pasta, fried potatoes, mayonnaise, Mexican dishes, egg dishes, popcorn, bacon, sausage and hot dogs. Eating less of these foods can also help you get a better balance of omega-6 to omega-3 fats.