By KRNC staff
Refined oils, including seed oils, have been available for over a century but recently have started to come under fire for their impacts on health. A quick search on Google and social media and you will have a never-ending list of videos and blogs about how seed oils are toxic, and that you should cut them out of your diet. Are the claims true? Are seed oils really that unsafe to consume? Let’s dig into what the research says.
What are seed oils?
Seed oils include a variety of refined vegetable oils where the oil comes from the seed of a plant, rather than the fruit itself. Common seed oils include corn, canola, grapeseed, and sunflower oils. For a long time, they have been known as the ideal oil to use for baking and cooking at higher temperatures due to their neutral taste and high smoke point.
What makes seed oils different?
There are several different types of dietary fats – saturated fats, trans fats, and unsaturated fats. Saturated fats mostly come from animal products like dairy, meat, and poultry with higher levels found in fattier cuts of meats, full-fat dairy products, coconut oil, and palm oil. Trans fats are a product of food processing and are usually found in fried foods, commercially prepared pastries and baked goods, shortening, stick margarine, and some nondairy coffee creamers. Unsaturated fats are predominately found in foods from plants including seed oils, olive oils, nuts, and seeds, along with fatty fish.
Unsaturated fats can be split into two more categories, monounsaturated and polyunsaturated fats. These categories are determined by the food’s content of omega-3, omega-6, and omega-9 fatty acids. While omega-3 fatty acids are well known for their positive impact on heart and brain health, omega-6 and omega-9 fatty acids have been less commonly talked about until recently when seed oils started gaining attention. Seed oils tend to be higher in omega-6 fatty acids and the message on social media is that this is not good for health and thus, should be avoided at all costs. But is this true?
What does the evidence say about omega-6 fatty acids?
Omega-6 fatty acids are essential fatty acids, meaning they provide a health benefit to the body and must be consumed through foods because our bodies cannot produce these fats on their own. It is important to consume omega-6 fatty acids alongside omega-3 fatty acids, which are found in foods such as salmon, walnuts, flaxseed, and chia seeds. Eating foods that provide this mix of unsaturated fats has been shown to reduce inflammation and decrease the risk of disease.
Evidence shows that the average American diet has become increasingly high in omega-6 fatty acids, and concurrently low in omega-3 fatty acids while health problems are on the rise – and seed oils are taking the blame for this trend. When omega-6 fatty acids are broken down, a by-product called eicosanoid can be formed. While this molecule has been linked to increased inflammation and blood pressure in lab studies, it is important to consider the potential limitations of lab studies. Lab studies may not accurately mimic the human body due to the artificial nature of their experiments. Research shows the link to increased inflammation and blood pressure happens in the lab, but eicosanoid is not produced in large quantities in the body. The small amounts of eicosanoid that are produced when consuming seed oils have not been shown to impact health, inflammation, blood pressure, and other chronic diseases, which is contrary to the loud messaging flooding social media. In other words, the link between seed oils and disease that is making headlines has been represented in lab studies but not human, clinical trials. It is important to note that while foods containing seed oils such as chips, fried foods, and bakery items may be linked to health complications, it is important to differentiate the seed oil in the ingredients from the high processing and low nutrient content of these types of foods. Overall, claiming that seed oils are harmful to health is not, in fact, an evidence-based claim.
Why should I keep seed oils in my diet?
Seed oils are part of one of the main food groups – fats – that play an important role in your body. Specifically, fats:
- Provide energy and satiety
- Protect organs
- Assist with the absorption of nutrients
- Regulate body temperature
- Support hormone health
Because of all these important roles, it is crucial to eat enough fat. The types and amount of fat you eat play a role in your health. So, what types should you eat? Let’s refer back to the different types of fat found in foods. Diets high in saturated and trans fats may increase the risk for certain chronic diseases, especially cardiovascular disease, so guidelines recommend limiting saturated fat intake to ten percent or less of your total daily intake. This leaves lots of room for the rest of your fat intake to come from unsaturated fat sources, including seed oils as well as olive oils, nuts, and seeds, and fatty fish. Overall, nutrient-dense diets higher in unsaturated fats can be health-promoting and lower your risk for chronic diseases.
What we know so far – seed oils, eaten in the mix with olive oil, avocados, omega-3-rich fatty fish, nuts, and seeds, are a health-promoting alternative to saturated fats, and a safe and nutritious food source to keep in your diet!
More Information:
For additional resources for healthy eating, check out these programs from our registered dietitian nutritionists. Find delicious and healthy recipes on our Recipes page! More health tips are also available at the College of Health and Human Sciences Pinterest board. Lastly, don’t forget to sign up for the KRNC monthly newsletter!
