Why Seed Oils Aren't As Bad As You Think.

In recent years, seed oils have become the recent villains in the world of health and wellness. From claims that they cause inflammation to accusations of being toxic, these common cooking oils have been demonized by influencers and trendy diets alike. But is this fear justified, or are seed oils just misunderstood? Let’s take a look at the science behind seed oils to find out.

Drayer, L. (2017, March 24). Are vegetable oils healthy? What you need to know. CNN Health.

What are seed oils?

Seed oils, like canola, sunflower, safflower, sesame, and soybean oil, are extracted from seeds that are rich in polyunsaturated fats, particularly omega-6 fatty acids. These oils are normally used for cooking and food preparation because of their versatility, mild flavor, and high smoke point.

Critics of seed oils argue that omega-6 fatty acids promote inflammation, but the reality is far more nuanced. While omega-6s can produce pro-inflammatory compounds, they are also essential for bodily functions, such as energy production, cell growth, and brain development.

The Science Behind Seed Oils and Health

1. Heart Health Benefits

A systematic review and meta-analysis published in Lipids in Health and Disease examined the impact of replacing saturated fats with unsaturated fats, such as those found in seed oils, on blood lipids. The study specifically focused on substituting saturated fats with polyunsaturated fats, like omega-6 acids found in seed oils. The results showed that seed oils help improve LDL cholesterol (bad cholesterol) and total cholesterol levels, which are key markers for heart health. By replacing saturated fats, commonly found in red meat and butter, with the unsaturated fats in seed oils, this study found a significant reduction in LDL cholesterol levels, which can lower the risk of cardiovascular disease

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2. Omega-6 Fatty Acids Are Not the Enemy

The idea that omega-6 fatty acids cause inflammation has been oversimplified. Research from Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease shows that linoleic acid, the primary omega-6 fatty acid in seed oils, is associated with a lower risk of cardiovascular events. These fats are beneficial when consumed in moderation.

3. Lower Risk of Diabetes

A 2021 study in The American Journal of Clinical Nutrition linked higher dietary intake of linoleic acid to a reduced risk of type 2 diabetes. This challenges the narrative that seed oils are inherently harmful and highlights their potential role in metabolic health. Rather than contributing to metabolic dysfunction, the study suggests that seed oils can be part of a strategy to improve insulin sensitivity and regulate blood sugar levels. This underscores the importance of viewing seed oils within the context of overall dietary patterns, rather than labeling them as inherently good or bad.

Why the Fear Around Seed Oils?

Much of the criticism around seed oils comes from their widespread use in processed foods and the imbalance ratio of omega-6 to omega-3 fatty acids in modern diets. However, this issue is not unique to seed oils; it’s a broader dietary pattern problem. The solution isn’t to eliminate seed oils entirely but to restore balance by introducing more omega-3-rich foods like salmon and walnuts.

Likewise, seed oils are typically found in ultra-processed foods like chips, popcorn, and fast food. This association has led many to blame the oils themselves for the negative health effects linked to these foods, rather than recognizing that the real culprits are the high levels of added sugar, refined carbohydrates, and excess sodium present in such products. Demonizing seed oils oversimplifies a complex issue and diverts attention from the importance of overall dietary quality. When used appropriately in home cooking and as part of a balanced diet, seed oils are not inherently harmful.

Practical Tips for Using Seed Oils

If you’re ready to stop being afraid of seed oils as part of a balanced diet, here are some types to ensure you’re using them healthily:

1. Choose High-Quality Oils: Opt for minimally processed, cold-pressed seed oils whenever possible to retain their nutrients.

2. Use Them in Moderation: Like any fat, seed oils should be consumed in reasonable amounts as part of a varied diet.

3. Avoid high-heat Cooking: While many seed oils have a high smoke point, repeated high-heat cooking can produce harmful compounds.

4. Balance Omega-6 and Omega-3 Fatty Acids: Incorporate omega-3-rich foods into your meals to maintain a healthy fat ratio.

I’m not suggesting you start using seed oils in your cooking if you don’t already (personally, I stick to extra virgin olive oil at home). Instead, I’m encouraging you to let go of the fear surrounding them. For instance, if you’re grocery shopping and come across a bag of popcorn with sunflower oil listed in the ingredients, there’s no need to avoid it. And if you’re truly determined to cut seed oils from your diet, the best approach might be to focus on reducing ultra-processed foods altogether, not just reaching for another ultra-processed snack with a different oil used. 

Instead of hyper-fixating on trace amounts of seed oils, it’s far more important to pay attention to the sugar and sodium content on labels–those are the real culprits impacting your health. While seed oils aren’t superfoods by any means, they are definitely not the villains they’ve been made out to be. By using seed oils wisely and in balance with other fats, you can consume them as part of a healthy, well-rounded diet.

References

Marklund M., et al. (2019). Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease. Circulation.

Mousavi SM., et al. (2021). Dietary Intake of Linoleic Acid and Risk of Type 2 Diabetes. The American Journal of Clinical Nutrition.

Schwingshackl L., Hoffmann G. (2014). Effects of oils and solid fats on blood lipids: a systematic review and meta-analysis. Lipids in Health and Disease.