The Scoop on Seed Oils

Seed oils are vegetable oils extracted from the seeds of plants such as canola, soybean, corn, cottonseed, sunflower, safflower, rice bran and grapeseed. Unlike oils that are mechanically pressed (cold-pressed), most seed oils are produced using heat and chemical solvents like hexane. This method is more cost-effective and efficient for large-scale production. While trace amounts of hexane may remain in the oil after processing, research indicates these levels are insignificant and likely dissipate when the oil is heated during cooking. For comparison, extra virgin olive oil is an example of a cold-pressed oil, though it's extracted from a fruit, not a seed.

Seed oils are notable for their high concentration of omega-6 essential fatty acids, primarily in the form of linoleic acid (a polyunsaturated fatty acid). They contain relatively lower levels of omega-3 fatty acids. This imbalance is often a point of contention because some omega-6 derived compounds are believed to promote inflammation, while omega-3s are known for their anti-inflammatory properties. However, this is really an oversimplification as some omega-6 derived compounds are anti-inflammatory as well. This has led to the common argument that consuming seed oils can contribute to chronic inflammation, which, over time, may increase the risk of conditions like type 2 diabetes, heart disease and certain cancers.

While the theoretical argument suggests that a high intake of omega-6-rich oils would promote inflammation, this theory doesn't always translate directly to the human body. Like how dietary cholesterol doesn't always directly correlate with blood cholesterol levels, the relationship between dietary omega-6s and inflammation in the body is more complex than a simple one-to-one interaction. Randomized, controlled trials have found that people who consume more seed oils don’t show more markers of inflammation. Further research continues to explore the nuances of how these fatty acids truly impact our health.

We tend to consume more omega-6s than we need and fewer omega-3s, in fact, many Americans eat about 10 times more omega-6s than omega-3s. Nutritionists agree that a balanced ratio is healthier, but it’s probably more important to increase your omega-3s in order to improve that ratio than to decrease your omega-6s.

Both omega-3 and omega-6 are polyunsaturated essential fatty acids (PUFAs). Omega-3s are found in the fat of shellfish and cold-water fish. Omega-6s are found primarily in seeds and grains (including seed oils), as well as in chickens and pigs. Unless you’re eating a very-low-fat diet, you are most likely getting more than the recommended amount of omega-6s.

Focus on the right balance of PUFAs: Eat foods or take supplements rich in omega-3 fatty acids, such as shellfish, cold-water ocean fish and fish oil (salmon, tuna, sardines, herring and anchovies, as well as non-fish sources such as flaxseed, almonds, walnuts and canola oil).

While seed oils are high in omega-6s, eating food that has been cooked with seed oil is a healthier option than eating processed foods, which also contain seed oils and are high in refined carbs, salt and sugar.

Atkins has always promoted and focused on consuming a balance of different fats, both saturated and unsaturated instead of one type of oil vs. another. Regardless of your oil choice, remember to focus on balancing your diet with a vibrant array of produce. A "rainbow" of fruits and vegetables ensures you're getting a wide range of essential vitamins, minerals, antioxidants and fiber. Prioritize whole foods when possible, but don't let the presence of a little oil stress you out. As with most dietary choices, moderation is key.