My approach to seed oils as a holistic dietitian
In recent years, seed oils like canola, sunflower, and soybean oil have come under fire. Some argue that they contribute to chronic inflammation, while others point to their benefits as a source of essential fatty acids and affordability. So what’s the real story behind these commonly used oils?
In this blog, we’ll explore:
what is considered a seed oil
omega-6’s and omega-3 fatty acids
the potential health benefits and risks of seed oils
processing methods
what to do around consumption
what are seed oils?
Seed oils are oils extracted from the seeds of various plants, and they are commonly used in cooking, food processing, and even cosmetics. Some of the most popular seed oils include canola, sunflower, safflower, sesame, soybean, cottonseed, corn, grapeseed, and rice bran. These oils are typically refined to remove impurities, which makes them have a neutral flavor and a high smoke point, making them ideal for frying and sautéing. But are they ideal for health? Let’s dig into it.
omega-6’s and omega-3 fatty acids
Omega-6 and omega-3 fatty acids are two types of polyunsaturated fatty acids (PUFAs). PUFAs are generally considered heart-healthy, and it’s encouraged to consume more foods that contain these. While omega-3s are very well known to have an anti-inflammatory effect on the body, omega-6s tend to have a more pro-inflammatory effect. We do need some degree of inflammation in the body, but too much can be problematic. It’s very important to have a good balance between these two types of fats in our diet, and this is where a lot of people fall short. It is thought that the ratio of omega-6 to omega-3 is too high (around 15:1) and should be closer to 4:1, meaning we should strive for less omega-6 intake and more omega-3 intake. This is where seed oils come in. Seed oils are very high in omega-6 fatty acids. They are typically found in tons of processed foods and are commonly used as cooking oils at home and in restaurants. Due to their omnipresence in our food system, we tend to have a very high intake of omega-6s. Before moving on, let’s touch on what foods are high in omega-3s and omega-6s.
Omega-3 rich foods:
ALA: flax, chia & hemp seeds, and walnuts
EPA/DHA: marine algae, fatty fish (salmon, tuna, mackeral, anchovies, sardines, herring, trout), and fish/krill oil supplements
Omega-6 rich foods:
found in a wide variety of nuts/seeds in varying amounts
nuts/seeds: walnuts, peanuts, pine nuts, brazil nuts, hemp seeds, sunflower seeds, pumpkin seeds, sesame seeds
oils: sunflower, safflower, soybean, corn, peanut, canola and "vegetable" oils
As you can see, there are a lot of nuts/seeds that contain omega-6s. Let me be very clear that this doesn’t make them bad. In fact all of these nuts/seeds are incredibly nutrient-dense, and great for health as a whole food! It really comes back to the ratio of omega-6s to omega-3s and ensuring there is a good balance. Seed oils are more processed, and as mentioned above are found in a ton of processed foods, making it tough to have a healthy ratio.
the potential health benefits and risks of seed oils
Here’s the deal. While lots of evidence (like this and this) suggests that increasing omega-6s benefits cardiovascular and overall health, other researchers suggest that higher intake of omega-6s, especially from seed oils, might not be cardioprotective. I think the problem here is that many of these studies are not specifically looking at seed oils, and are instead looking at omega-6 intake as a whole. Therefore, it’s difficult to extract the exact impact of seed oils, which is why those who defend seed oils say that there is not enough evidence to point to them being harmful. They suggest it’s likely the processed foods themselves (that happen to contain seed oils) that are harmful. And I agree with that! To get the full picture, though, let’s dig into the processing methods of these oils.
processing methods
Seed oils are often extracted using a chemical process that involves the use of hexane, a solvent that helps to separate the oil from the seeds. Hexane is used extensively in the food industry for the extraction of various products beyond oils, including fats, flavors, fragrances, and color additives. In this process, the seeds are first crushed to release their oil, and then hexane is used to dissolve and extract the remaining oil. After extraction, the hexane is typically evaporated, leaving behind the oil, but traces of the solvent can sometimes remain. The FDA does not currently regulate hexane residue in oils, so it’s unknown how much is left behind. While the amounts of hexane left in the final product are usually considered minimal and within safety standards, concerns persist about the long-term health effects of consuming oils that have been exposed to chemical solvents. Additionally, the use of hexane is often associated with environmental issues, as it can be harmful to both air quality and ecosystems when not properly managed. Some critics argue that this chemical extraction process, along with the refining methods that follow, may compromise the nutritional quality of seed oils and contribute to the production of unhealthy fats and oxidation byproducts.
so… should you have them?
Even as a holistic dietitian, I want to start by saying that any extreme language around completely avoiding a food/ingredient and creating fear around it is a BIG red flag for me. I’ve seen videos where people literally bring their own avocado oil to restaurants and request that their food be cooked in that oil. That is completely insane (and disrespectful) to me. I definitely don’t align with people/health care providers that tell their followers/clients to never consume seed oils. Americans aren’t unhealthy because of seed oils. The majority of Americans are unhealthy because over 60% of their diet comes from processed foods, they eat out at fast food restaurants way too often, and they don’t move enough. For some these are intentional decisions; for others, it’s related to poor access to healthy foods. Of course, there are other contributors to poor health such as excess stress, exposure to environmental toxins, etc., but poor food choices and lack of movement are the main reasons as to why we are unhealthy.
That being said, considering that seed oils are in so many processed foods and we don’t eat enough omega-3s to balance out the pro-inflammatory properties of omega-6s, I think it is worth making different food choices that would ultimately lead to less consumption of seed oils.
Below are 5 simple things in your control that you can focus on:
Decrease your overall consumption of processed foods and fast foods! If you’re focusing on mostly whole foods, then you are in a really good place.
Eat fatty fish 2x per week and one tbsp of omega-3 nuts/seeds most days of the week (hemp, chia, flax, walnuts) to increase your omega-3 intake.
Stick to mostly olive or avocado oil when cooking/baking at home (these are highest in monounsaturated fats, which are the healthiest fats to consume!)
Get your omega-6s from whole food options, such as the nuts listed above!
If available, replace foods that have seed oils with other options that use olive oil or avocado oil instead
examples: salad dressings, dips, mayonnaise and other condiments, popcorn, crackers, etc.