It seems as if every other week I come across another news story touting the benefits of the essential fatty acids (EFAs) found in fish oil. But the truth is that fish oil’s role in good health is nothing new. Nordic populations often credit their hardiness to a diet high in fish. So it didn’t surprise me to learn that the first studies of fish oil came out of Denmark.
The extraordinary health benefits of fish oil were first discovered back in the early 1970s, when doctors in Denmark studied Eskimos living in Greenland. They noticed that the Eskimos had fewer heart attacks and a much lower incidence of arthritis than the Danes, despite the fact that the Eskimos ate a high-fat diet. Studies from around the globe have since revealed that the benefits of fish oil come from two omega-3 fatty acids—EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Not surprisingly, these two healthy nutrients are found in the fatty tissue of the fish consumed in great quantities by the very Eskimos who took part in that early study.
Omega-3 fatty acids have potent properties that quell inflammation, support a healthy heart rate, and discourage blood clots and clogged arteries. They’re primarily found in fish with high oil contents, such as anchovies, kippers, mackerel, herring, salmon, sardines, trout, and tuna. Omega-3 fats are also found in plant oils, nuts, and seeds, as well as many fruits and vegetables. One of the best plant sources is flaxseed.
Omega-6 fatty acids, however, are found in the oils of seeds and grains such as sunflower, safflower, wheat, corn, and soy. Omega-6s are important for stimulating skin health and hair growth, maintaining bone health, regulating metabolism, and maintaining reproductive capability. Both of these EFAs are important to good health—but only if they’re consumed in the right ratio.
Thousands of years ago, people ate equal amounts of these two types of fatty acids. But today, the standard American diet focuses on too much omega-6 and not enough omega-3—an imbalance that may contribute to chronic health problems including cardiovascular disease, cancer, and autoimmune diseases. According to Artemis Simopoulos, MD, the president of the Center for Genetics, Nutrition, and Health, located in Washington, D.C., most American diets contain around 20—30 times more omega-6 fatty acids than omega-3s. A diet ratio closer to 1:1 would be far healthier.
While the benefits of EFAs for heart and brain health are quite well known, an increasing number of studies show that omega-3 fatty acids can have positive impacts on other health conditions.
Healthy Eyes. According to the poets, our eyes are the windows to the soul. Unfortunately, they’re also vulnerable to the effects of free-radical damage and chronic inflammation. While it has been confirmed that omega-3 fatty acids help enhance vision in infants, they might also help protect our eyes as we age.
Although cataracts and glaucoma are common among older people, the most frightening disease to attack vision is age-related macular degeneration (AMD). AMD is a degenerative retinal disease. The macula—the area at the back of the retina that controls fine vision—deteriorates, resulting in central vision loss and even blindness. It’s the most common cause of vision loss in Americans over 60—and the odds just get worse as we get older. In fact, one in three people over the age of 75 are affected by AMD.
While family history and bad habits such as smoking can increase your risk of developing AMD, there’s new evidence that high levels of dietary fat are associated with the disease’s progression. And it seems the biggest culprits are saturated fat, trans fats, and omega-6s. Yet, researchers at the University of Melbourne recently pooled data from nine different studies and found that a high intake of omega-3 fatty acids may help reduce the risk of AMD by up to 38 percent.
Other research has indicated that the balance of the fatty acids in the eye can influence macular-degeneration risk, possibly by affecting inflammation.
EPA and DHA may also help those who already suffer from this debilitating disease. According to researchers at the University of Rome, taking fish oil supplements not only protects those suffering from AMD against further damage, but it actually improves their vision.
Of course, AMD isn’t the only common eye problem. Staring at a television or a computer monitor can reduce the amount of times we blink, and this decreased blinking can result in the excessive evaporation of tears. Known as dry eye syndrome (DES), this condition afflicts more than 10 million people in the U.S. Artificial tears offer only temporary relief, and expensive prescription drugs promise help—at the cost of potentially serious side effects.
Could fish oil be a viable alternative? Research published in the American Journal of Clinical Nutrition suggests that could be the case. The trial, which was part of the Women’s Health Study, found that women whose diets provided the highest amounts of omega-3 fatty acids had a 17 percent lower risk of DES. In contrast, women whose diets supplied a high ratio of omega-6 to omega-3 fatty acids had more than twice the risk of DES compared to those with a more balanced intake of fatty acids.
Stronger Immunity. If you want to boost your immune system, you probably reach for vitamin C or Echinacea. But evidence suggests that omega-3 fatty acids may be useful for protecting against certain infections and treating a variety of conditions. This makes sense because, when they’re ingested in the right ratio, omega-6 and omega-3 fatty acids help regulate immune and inflammatory responses.
Omega-3s work by increasing the activity of phagocytes, the white blood cells that eat up bacteria. These fats also help strengthen cell membranes, thereby speeding healing. Plus, they help increase the body’s resistance to infection.
Because omega-3s are able to tamp down chronic inflammation, German researchers speculate that these fatty acids may be able to help surgical patients and those with respiratory problems. Omega-3 fatty acid supplementation may also help reduce stress and the effects it has on the body.
Better Bones. Everyone knows that supplemental calcium and vitamin D can help build strong bones. But you might want to add fish oil to that regimen. New research shows that omega-3s improve bone structure by boosting the absorption of calcium, maintaining bone mineral density, and reducing bone loss, especially in post-menopausal women.
Omega-3s also appear to help build bone mass and bone strength—at least in young adults. A cohort study of 78 young men discovered that those with the highest blood levels of omega-3s had more bone mass and higher bone density than those with lower blood levels.
The conditions highlighted here are well documented as responding to omega-3 fatty acids. But a growing number of studies suggest that fish oil can benefit even more conditions, including:
When you look at all that evidence, it’s pretty easy to see that adding more fatty fish—and fish oil supplements—to your diet is a simple, commonsense step towards improving overall health.
What's the difference between cod liver oil and regular fish oil? We asked nutrition expert Robert Wildman, PhD, RD, LD. "Cod liver oil is derived directly from the liver of cod and like fish oil, which is derived from the flesh of other fish, cod liver oil has a high level of omega-3 fats DHA and EPA, but also vitamins A and D," he says. Robert Wildman is the author of The Nutritionist: Food, Nutrition & Optimal Health and creator of TheNutritionDr.com. Follow him on twitter at TheNutritionDoc.