This topic I’m about to discuss is one that brings a lot of heat to conversations. You’ve probably heard opinions about various food additives from friends, from politicians and food policy makers, people that claim themselves to be a nutritionist or health and wellness expert, and social media influencers sharing what works for them then writing it as a diet for anyone that stumbles upon their page. However, do these people really understand the science behind the food that humans eat? Are health benefits from including these foods part of the conversation? Do they understand the current policies and procedures America puts in place regulating our food to ensure it's safe to eat, from infants to our elders? This blog will start with the food additive seed oils, by breaking down the facts behind this food source, their purpose in the foods we eat, and how to make an informed decision on whether it's a food you will consume.
My disclaimer for this topic: in no way will I change everyone’s already preconceived opinion on the topic of food additives, and I am not judging anyone for their food choices or their strong feelings towards what they do and don’t eat. My intention for this blog is to give the facts on food additives and provide a more food neutral approach versus fear mongering and demonization.
Food additives
The legal definition for food additives, per the US Department and Human Services’ website, is "any substance with the intended use of which results or may reasonably be expected to result (directly or indirectly) in its becoming a component or otherwise affecting the characteristics of any food". In simple terms, food additives are ingredients incorporated in food to help meet a desired texture, consistency, flavor, color, preservation and/or health benefit. Seed oils are just one example of a food additive because they are a more cost effective oil, help preserve food and increase shelf life, have high smoke points to improve the cooking process, and are a heart healthy alternative to saturated fats and replacing once-used artificial trans fats.
Seed oils: what are they?
The term seed oils includes corn, grapeseed, canola, safflower, cottonseed, sunflower, soybean, and rice bran oils. Oils from these foods are extracted chemically, which may include cleaning, pressing, deodorizing, bleaching, and expressing, or mechanically, i.e. cold pressed or expeller pressed. More commonly the method is chemical extraction to give them the greater shelf-life characteristic, and is not unique to just these oils. The possible downside is once a rich source of antioxidants like vitamin E and polyphenols, this gets broken down in the process. To note, seed oils are not the only source of these rich nutrients, and why a balanced diet and variety of oils is important.
The use of seed oils in our food
Seed oils are added as ingredients to food and are a part of food preparation. One reason being is they tend to have a high smoke point, making them a good choice for cooking at high heats. What this means is that these oils can withstand temperatures subject to methods of cooking that include frying, pan searing, or sauteeing, typically 400F or higher, without breaking down and starting to release unwanted toxins. Another is that in the refining process, compounds are destroyed that cause rancidity resulting in a stabler product and increased shelf life.
Are seed oils inflammatory?
Seed oils are a rich source of unsaturated fats, more specifically PUFAs (polyunsaturated fats). These fats have been shown to contain heart healthy properties through improving high density lipoprotein (HDL) levels, reducing total triglycerides, and reducing inflammation. Replacing saturated fats with unsaturated fats may provide a cholesterol and low density lipo protein (LDL) lowering effect. Seed oils contain a mix of omega-3 and omega-6 PUFAs, typically higher in omega-6. The term omega, followed by the number, is referring to where a carbon-to-carbon double bond is located in the fatty acid chain.
Omega-6 fats play a vital role in heart, brain and hormone health, just to name a few bodily functions, and support the integrity of cell membranes. Some critics will argue that the higher ratio of omega-6 to 3 will increase inflammation because the most common form, linoleic acid, gets broken down into arachidonic acid, which is one known building block for some inflammatory markers in the body. The extent to which this occurs is very minimal, and little evidence to support this claim. Furthermore, omega-6/linoleic acid has also been shown to counteract chronic inflammation.
Weighing the cost versus benefits of seed oils
Over the last year seed oils have been called toxic, inflammatory, and various influencers have encouraged their followers to avoid them. What we do know about these oils is they are a good source of unsaturated fat, more specifically a mix of omega-3 and omega-6 fatty acids, and actually contribute to reducing inflammatory markers and improving heart health more than the risks of omega-6 increasing the chance of inflammation. Like any nutrient consumed, it should be considered as part of a balance in one’s diet. What critics are saying about these oils may not even be from the oils themselves, but other compounding factors in someone’s diet or stress from different areas in their life. Consider these questions as you read through claims about seed oils: Can the individual making these claims explain to you the chemical breakdown of linoleic acid, then explain how and why it’s inflammatory? Do they recognize the positive health benefits? What are they trying to sell you instead? Are they screening for different types of stress that may be increasing someone’s risk for chronic inflammation, such as financial strain and living in a food desert? Do these individuals know how and what I eat in a day?
Truly there is power in eating nutrient dense foods and making informed decisions about how much and what we eat, but adding extra stress to food decisions and demonizing food as good and bad does not support overall health and may risk someone missing out on important nutrients. And this fits for seed oils. So instead try a “what can I include” approach with food rather than “what do I need to cut out” to encourage nourishing your body through a more food-neutral lens.
So the answer to the question of “should I avoid seed oils?”, I recommend no as the argument to incorporate them is strong. Ultimately it’s up to an individual on whether they decide to cut these ingredients out of their diet, and that’s their nutrition journey and they have the right to do so. My advice as a registered dietitian, and this is the same advice I’m providing to my clients, is to weigh the cost vs benefits of seed oils, understand that they are supportive to overall health with antiinflammatory properties, and practice applying a food neutral approach to health rather than a good and bad foods thought process.
Some resources that helped develop this blog:
https://www.hhs.gov/answers/public-health-and-safety/what-is-a-food-addititve/index.html
https://pubmed.ncbi.nlm.nih.gov/28752873/
https://www.gbmc.org/greater-living/demystifying-seed-oils-separating-fact-fiction
https://engagement.source.colostate.edu/are-seed-oils-bad-for-you-registered-dietitian-explains/
https://www.ahajournals.org/doi/full/10.1161/circulationaha.108.191627
https://www.massgeneral.org/news/article/seed-oils-facts-myths