Omega-3 Essential Fatty Acids
Fat has a bad reputation – many people associate dietary fat with obesity, heart disease and other chronic conditions. But not all fat is bad fat. Some fats, known as omega-3 fatty acids, can lower the risk of heart disease, fight arthritis and other inflammatory disease, improve brain function and enhance immune function.
In the late 1970s, Danish researchers compared the rates of heart disease among Eskimos in Greenland to those among Danish populations. Despite their high-fat diet, the Eskimos were much less likely to suffer from heart disease than their Danish counterparts. How could this be?
Scientists hypothesized that Eskimos experienced such low rates of heart disease because of their consumption of fish, whales and other marine mammals, all of which are high in omega-3 polyunsaturated fatty acids. Epidemiological studies of fish-eating populations in Japan and elsewhere supported this hypothesis, and subsequent research confirmed it. In 2000, researchers at the Mid America Heart Institute in Kansa City wrote that more than 4,500 studies confirmed the cardiovascular benefits of omega-3 fatty acids. The research on omega-3 fatty acids from marine sources may also apply to omega-3 fatty acids from flaxseed and other plant sources.
Not All Fats Are Created Equal
The human body can produce most of the fat it needs from carbon, hydrogen and oxygen. But the body can’t produce omega-3 and omega-6 fatty acids, although it needs both. Because these fats must be obtained from the diet, they are called essential fatty acids, or EFAs.
There are three types of omega-3 fatty acids: eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and alpha-linolenic acid (ALA). The body can most readily use EPA and DHA, which are found primarily in fish and marine mammals. The body converts ALA, which comes from plant sources such as flaxseed, into DHA and EPA.
The other essential fatty acids – omega-6 fatty acids – are vital to our health, but most of us get too much of them in our diet. Most vegetable oils toady are high in omega-6 fatty acids and low in omega-3 fatty acids, and the imbalance can cause health problems like heart disease, cancer and autoimmune disease. For instance, a 2004 article linked cystic fibrosis to an imbalance of fatty acids.
In today’s diets, the ratio of omega-6 to omega-3 fatty acids is nearly 15 to one – far from the ideal one-to-one ratio of essential fatty acids that scientists believe our ancestors ate. However, we can probably improve our overall health even without achieving the ideal ratio. In 2002, Artemis Simopoulos, president of the Center for Genetics, Nutrition and Health in Washington, DC, reported that the EFA ratio needed to reduce health risks varies from condition to condition. For example, a four-to-one omega-6 to omega-3 ratio may reduce the risk of dying from heart disease by 70 percent, but reducing the spread of colon cancer requires a 2.5-to-one ratio.
How Do Essential Fats Help the Body?
EFAs can help reduce the stickiness of blood platelets, reducing the risk of atherosclerosis (hardening of the arteries), stroke and heart attack. EFAs can also help lower levels of triglycerides and LDL cholesterol. EFAs have even been shown to have anti-inflammatory effect that can help fight illnesses such as arthritis, irritable bowel syndrome, asthma and more. In fact, EFAs in breast milk may reduce the risks of asthma and other atopic conditions in children.