The Seed Oil Scaries
This week’s newsletter will explore the latest culprit in the war on processed food in America.
I’m sure you’ve heard all sorts of comments around seed oils and why they are so bad. A number of restaurants including salad giant Sweetgreen even went as far as to completely remove them from their menus. The world of health and wellness podcasters, TikTok doctors, and Instagram influencers have raged a war against these substances, but are they really what society has cracked them up to be? We’re here to unpack exactly what they are and if they are really the worst things for you.
What are seed oils?
Seed oils are vegetable oils made from the seeds of various plants. They are commonly used in cooking and food preparation due to their neutral taste and high smoke points.
Common types of seed oils are (sometimes referred to as the “hateful 8”:
Canola Oil
Sunflower Oil
Grapeseed Oil
Cottonseed Oil
Rice Bran Oil
Safflower Oil
Soybean Oil
Corn Oil
These oils are primarily composed of unsaturated fats, which are split into monounsaturated and polyunsaturated fats, including omega-6 and omega-3 fatty acids.
Historically seeds used to make these oils have been linked to heart health benefits, such as lowering cholesterol levels and reducing the risk of heart disease. They also have omega-6 fatty acids which are beneficial to the body and shown to reduce inflammation and decrease disease risk. Studies indicate that replacing saturated fats with polyunsaturated fats such as linoleic acid can lower cholesterol levels. However, this decrease in cholesterol does not correspond to a reduction in mortality rates. Consequently, many experts are now questioning the broad public health endorsement of a high linoleic acid intake.
The problem is that too much of omega-6 fatty acids can change the way cells react and in turn have harmful effects on cells in the heart and blood vessels. The argument suggests that linoleic acid, a prevalent omega-6 fatty acid, is transformed into arachidonic acid within the body. This supposedly results in the production of other compounds that elevate inflammation levels throughout the body leading to acne, weight gain, infertility, and increased risk of chronic disease.
A wide variety of conditions including diabetes, cancer, heart disease, Alzheimer’s, and arthritis involve inflammation, which is one of the main arguments behind the warnings against seed oils. But before you eliminate all of these from your pantry immediately it’s important to note that there is a lot of misinformation regarding the toxicity of seed oils on social media. In reality, many of these claims about seed oils are not supported by robust scientific evidence. It's important to differentiate the effects of the oils from the highly processed foods they are often found in. Ultra processed, fried, and generally unhealthy foods are often cooked in these seed oils, which can contribute to the chronic inflammation mentioned by many seed oil skeptics.
History of Seed Oils
Prior to 1900, cooking fats were mainly animal based products like butter and lard. Seed oils were not widely used in cooking, but were often utilized in industrial applications such as paints and polishes. Hydrogenation was able to transform these oils into the seed oils we now see today on grocery store shelves (cottonseed oil, a waste product of farming, was able to be transformed into Crisco through this process). This marked the beginning of seed oils’ integration into the American diet. In its early days, Crisco was marketed as a healthier and modern alternative to animal fats. By the mid 20th century, soybean oil had become the most popular vegetable oil in the US, surpassing cottonseed oil due to its versatility and lower cost.
With this rapid increase in the consumption of seed oils, came a wave of criticism of high consumption of these fats due to their high omega-6 fatty acid content. In the past 100 years, the balance of omega-3 fatty acids (anti-inflammatory) to omega-6s in our diet has changed from about 8:1 to 20:1, which poses a real issue for consumers. Both of these fats are considered polyunsaturated fats because we don’t have enzymes to produce them, so you must get them from your diet. Balancing these fatty acids is vital for our health and imbalance disrupts the body’s natural inflammatory response, promoting chronic inflammation. Consuming both omega-3s and omega-6s is essential, but it is important to do so as close to an even ratio as possible versus the average high omega-6 diets many Americans currently consume.
Today, seed oils are ubiquitous in processed foods, contributing significantly to the American diet. They are also prevalent in other goods such as cosmetics and haircare, so naturally it is hard to escape them in today’s world. There is growing awareness of their over consumption and debate about their long-term health impacts, leading some to advocate for a return to more traditional fats like butter and ghee.
So what’s the consensus?
Too many omega-6 fatty acids are bad for you, so consumption in moderation and balancing them with omega-3 fatty acids like salmon, chia seeds, tuna, etc. is key.
The processing of seed oils can lead to the formation of trans fats and other harmful compounds, so be aware of how they are made and opt for high-quality seed oils versus industrialized ones.
Most seed oils go through a refining process which strips them of their natural healthy antioxidants such as Vitamin D and phenols, so most brands we have access to at stores or restaurants are not additive to our diet.
Most seed oils are being used in the form of processed and packaged foods, fast foods, and other unhealthy options, which is really where the issue lies.
Almost all Americans consume too much of them, so they are inflammatory given the imbalance with omega-3s in our bodies.
When you cut out seed oils, that usually means you are cutting out processed foods, which is undeniably better for you. In reality, it’s less about the seed oils themselves and more about the fact that they are often found in unhealthy foods that cause inflammation and contribute to diseases independently of these oils.
Ultimately, it isn’t necessarily the seed oils themselves that are poisoning us, but what they are cooking and the amount in while we are consuming them. According to an article from the Harvard School of Public Health, “Repeatedly heating unsaturated fats to high temperatures, such as in restaurant deep-fryers where oil is infrequently changed, is a health concern, Crosby said. However, he added, “Cooking with seed oils at home isn’t an issue.”
Seed oils and their history represent a broader theme in America of industrialization, marketing, the impact of big food, and new wave of health science. While in the early days, seed oils offered a cheaper, more accessible way of cooking and eating, overconsumption and ultra processing turned them into potentially harmful substances given the prevalence of their use in products. Like almost everything in life, the key here is moderation, seed oils here and there will not kill you, but being mindful of your consumption and balance between anti-inflammatory fats is crucial.
Ultimately, it is on each and every consumer to educate themself and make choices that are in their best interest. As for myself, I try to limit seed oils, choose cleaner options when possible, and be cognizant of my consumption. I don’t believe in an all or nothing mindset when it comes to health. Frankly, living in America today, it’s almost impossible to rid our lives of every toxin and potentially harmful substance, but making small choices every day can greatly improve our quality of life and the impact these things have on our health and wellbeing.