Seed Oils & Inflammation
“Seed oils cause inflammation”?! Seed oils have been under fire in the social media world, mainly for being “inflammatory,” as many influencers say. So what exactly are seed oils? Is there any truth to these claims? Should we limit seed oils? Let’s break it down, starting at the beginning.
What are seed oils?
Most people referring to seed oils are referring to oils including canola, corn, cottonseed, soybean, sunflower, safflower, and rapeseed oil. These oils are often used in cooking or incorporated into processed food products.
What are people saying about seed oils?
“Canola oil is toxic sludge.”
“Seed oils are bad for you.”
“Seed oils are inflammatory.”
“Seed oils are toxic to the human body.”
…Just to name a few.
But is there any truth here? Not really.
What we can say, based on evidence-based scientific research, is that seed oils contain inflammatory fats. However, while we’re discussing inflammatory fats, it’s also important for us to discuss the types of fats overall, including anti-inflammatory fats.
Types of Fats:
When looking at nutrition facts labels, under total fats you will see a few categories, including Saturated fats, Trans fats, Monounsaturated fats, and Polyunsaturated fats.
Saturated fats are solid at room temperature and are found in animal-based foods like meat, poultry, dairy, and eggs, as well as tropical oils like coconut and palm oil. Saturated fats are necessary for overall health, but too much can increase LDL cholesterol levels and increase the risk of heart disease. The American Heart Association recommends aiming for a dietary pattern that achieves 5-6% of total daily calories from saturated fats.
Trans fats can be naturally occurring in some foods like milk and meats, or artificially created in a process that adds hydrogen to liquid vegetable oils, making them more solid. The primary dietary source of trans fats is processed foods as “partially hydrogenated oils.” In November 2013, the FDA made a determination that partially hydrogenated oils are no longer Generally Recognized as Safe (GRAS) in human food, and since then the use of them in foods has been restricted. The American Heart Association recommends cutting back on foods that contain partially hydrogenated oils to reduce trans fat in your diet.
Monounsaturated fats are typically liquid at room temperature but start to turn solid when chilled and they support health by helping to reduce LDL cholesterol levels, lowering the risk of heart disease. Examples of oils that are rich in monounsaturated fats include olive oil, canola oil, peanut oil, safflower oil, and sesame oil. Monounsaturated fats can also be found in avocados, peanut butter, nuts, and seeds.
Polyunsaturated fats are also typically liquid at room temperature but start to turn solid when chilled. They also, like monounsaturated fats, can help reduce LDL cholesterol levels and lower the risk of heart disease. Polyunsaturated fats also provide essential omega-3 and omega-6 fatty acids that the body needs, but cannot produce itself. This is where we get into the inflammatory vs anti-inflammatory debate… but first, a few sources of polyunsaturated fats include soybean oil, corn oil, sunflower oil, walnuts, sunflower seeds, tofu, and soybeans.
Omega-3 vs Omega-6 and Inflammation:
Omega-3 and Omega-6 fatty acids are both found in polyunsaturated fats and are both necessary for health.
Omega-3 fatty acids can either provide alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), or docosahexaenoic acid (DHA). ALA is an essential fatty acid (meaning your body cannot make it), and while the body can convert a small amount of ALA into EPA and DHA, it cannot do it enough to meet the body’s general needs, requiring us to get EPA and DHA from the diet as well.
ALA can be found in plant oils like flaxseed oil, soybean oil, canola oil, walnuts, and chia seeds.
EPA and DHA can be found in fatty fish, like salmon, mackerel, sardines, tuna, as well as sometimes in eggs and fortified foods.
In the United States, most adults consume the recommended amount of omega-3s as ALA, but DHA and EPA only make up a very small amount of omega-3 consumption.
Omega-6 fatty acids are also necessary for health, as they also support many body functions. Omega-6 fatty acids can be found in oils like corn, soybean, cottonseed, etc, as well as some animal products and nuts and seeds.
So if we need both omega-3 and omega-6 fatty acids, where does inflammation come into the story and why is that important?
Inflammation:
While omega-3 and omega-6 fatty acids both play important roles in the body and support health, omega-3 fatty acids are known to cause an anti-inflammatory action in the body while omega-6 fatty acids have a mostly pro-inflammatory impact. This does not mean what most social media influencers jump to say – that omega-6 fatty acids should be completely avoided. What matters is the ratio of omega-3 fatty acids to omega-6 fatty acids in our daily diet.
Consistently undereating omega-3 fatty acids, especially while eating excessive omega-6 fatty acids, can cause more inflammation in the body, increasing the risk of disease and illness. It has been found that the typical Western diet is high in omega-6 consumption while also being deficient in omega-3 fatty acid intake, steering away from the protective ratio of higher omega-3 compared to omega-6. This imbalance causes an increased risk of chronic inflammatory diseases, such as heart disease, rheumatoid arthritis, IBD, Alzheimer’s, etc.
What to do:
Knowing that both omega-3 and omega-6 fatty acids are necessary for health, it is not necessary, or recommended, to completely avoid all foods that contain omega-6 fatty acids. Instead, what would be most beneficial for the average adult in the United States is to be mindful of the consumption of processed foods that contribute large amounts of omega-6 fatty acids while also prioritizing higher omega-3 fatty acid intake. The combination of increasing omega-3s while reducing omega-6s can help get the body back to a better ratio of anti-inflammatory versus inflammatory fats, reducing the risk of inflammatory disease.
Many oils, including seed oils, contain both omega-3 and omega-6 fatty acids. Knowing this, any seed oils you enjoy using in your diet can be perfectly healthy as part of an overall well-balanced diet that supports the ratio of more omega-3 than omega-6.
- When cooking, choose oils that are best for the cooking method and temperature.
- When enjoying convenient processed foods, choose the ones that are the most beneficial for you and enjoy them in moderation as part of an overall balanced diet.
- Increase consumption of omega–3 boosting foods like fish, nuts, and seeds. (Try my super easy recipe for Guac Tuna Salad!
- Supplement as needed. Talk with your doctor or a dietitian directly to discuss whether or not a supplement, such as fish oil, would be beneficial in increasing your omega-3 intake for your overall health.
Recap:
In regards to inflammation, seed oils aren’t the problem. An excess of omega-6 fatty acids with a deficiency of omega-3 fatty acids is the problem. If a seed oil contains more omega-6 fatty acids than omega-3 fatty acids, consuming that oil does not automatically put your body in a pro-inflammatory state.
Rather than falling for fear-mongering social media posts carefully designed to provide the “shock” factor for more views, comments, and publicity, follow the science and speak to professionals who can help you understand how different foods and nutrients impact your body.
So, have no fear if you find your favorite snack food contains sunflower oil or if you use canola oil for cooking. Stress causes inflammation in the body too – so increasing stress at the supermarket when trying to find seed-oil-free foods isn’t going to help much either. 🙂
Sources:
https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
https://www.todaysdietitian.com/newarchives/040113p38.shtml
https://www.health.harvard.edu/newsletter_article/no-need-to-avoid-healthy-omega-6-fats