Omega-3 fats are a family of essential fats, or fats that cannot be made by your body and must be obtained from foods. Another essential family of fats called the omega-6s go hand-in-hand with understanding omega-3s, Susan explains. She says that few people realize that all omega-3s originate in the green leaves of plants and algae. The omega-6s originate in the seeds of plants, a key evolutionary difference, says Susan. This is why grass-fed beef as well as fish are especially high in omega-3s, whereas corn-fed animals have excessive amounts of omega-6s, according to Susan.
Susan says each type of fatty acid has important functions, and that humans require both types. The key, says Susan, is to eat the correct ratio of omega-3s to omega-6s. If the level of one of the fatty acids is too high, it competes with and interferes with the functioning of the other, she says.
The ideal ratio of omega-6 to omega-3 is still unknown, but Susan says a good rule of thumb is to eat more omega-3s and fewer omega-6s. She says the Japanese diet, which has a 4:1 ratio of 6s to 3s, is widely believed to be among the best ratios for overall health.
According to Susan, good sources of omega-3s include green leafy vegetables, omega-3 enriched eggs, fish and nuts. She recommends avoiding seed oils rich in omega-6s that compete with the omega-3s, such as safflower, sunflower, peanut and corn oils.
Grass-fed animals, says Susan, contain significantly more omega-3s than their corn-fed counterparts. Therefore, she stresses the importance of eating meat and eggs from organic, free-range, grass-fed animal sources.
Susan says she uses canola oil, butter and olive oil in her cooking. "It's surprising but butter doesn't have many of either of the two essential families of fats in them, but the fats that they do have are very balanced," she says. "So butter is a good thing to eat in small quantities."
Susan cautions that cooking at high temperatures can damage the essential fats in good oils. To prevent rancidity, Susan says oils should be stored in dark containers in cool areas, or refrigerated.