Seed Oils, Inflammation, Cholesterol, and Energy: What Does the Science Really Say?

Why Inflammation Matters More Than We Think

Chronic low-grade inflammation is a major driver of:

• Cardiovascular disease

• Insulin resistance

• Brain fog and fatigue

• Accelerated aging

Inflammation is also energetically expensive for the body. When the immune system is constantly activated, more energy is diverted toward managing inflammation and oxidative stress, leaving less energy available for the brain, muscles, and metabolism. This is one reason people with chronic inflammation often feel tired, unmotivated, or mentally foggy.

The Problem Isn’t Just Seed Oils. It’s How They’re Used

Most research supporting seed oils looks at them in isolation or in unheated form. In reality, seed oils are commonly:

• Highly refined

• Heated to high temperatures

• Reheated multiple times

• Used in ultra-processed foods

Polyunsaturated fats, especially those* rich in linoleic acid (omega-6), are chemically unstable when heated. High temperatures cause these oils to oxidize, forming lipid oxidation products that promote vascular inflammation and atherosclerotic plaque formation.

*Polyunsaturated fats rich in omega-6:  safflower  oil (78%), grape seed oil (73%), sunflower oil (68 %), corn oil (59%), cottonseed oil (56%), soybean oil (51%), sesame oil (45%), canola oil (20%)

What the research shows:

An animal study published in Nutrients (2018) found that rabbits fed heated corn oil developed significantly more fatty streaks and fibrous plaques in their arteries compared to rabbits fed heated palm oil, a more heat-stable fat. This suggests that oxidized polyunsaturated oils may actively contribute to atherosclerosis when used in cooking.

Cholesterol Numbers vs. Cholesterol Quality

Lowering cholesterol alone does not automatically reduce cardiovascular risk. A randomized controlled trial (2017) in healthy adults examined the effects of increasing linoleic acid intake from soy oil over 8 weeks. While common inflammatory markers like CRP did not increase, researchers observed significant increases in:

• Oxidized LDL (a marker of the early stages of atherosclerosis, inflammation, CVD)

• ApoB (crucial indicator of cardiovascular disease risk)

• Lp-PLA₂ activity (a marker of vascular inflammation)

This means that cholesterol became more prone to oxidation, which is far more damaging to blood vessels than cholesterol levels alone. Oxidized LDL is directly involved in plaque formation and vascular inflammation, processes that also impair blood flow and oxygen delivery, further reducing energy production.

What About Phytosterols in Canola Oil?

Canola oil is often marketed as beneficial because it contains phytosterols, plant compounds that reduce cholesterol absorption. While this sounds positive, animal research suggests a more nuanced picture.

In an experimental study (2010), rats consuming high-phytosterol diets derived from canola oil experienced significant increases in both systolic and diastolic blood pressure, despite lower cholesterol levels. This indicates that cholesterol lowering alone does not guarantee cardiovascular protection, and excessive phytosterol intake may have unintended vascular effects.

Processed Foods, Seed Oils, and Energy Crashes

Seed oils are a major ingredient in ultra-processed foods, which are also high in refined carbohydrates and sugars. This combination is especially problematic because it:

• Triggers repeated insulin spikes

• Promotes insulin resistance over time

• Increases inflammatory signaling

• Leads to post-meal energy crashes

When blood sugar rises quickly and then drops, people experience fatigue, cravings, irritability, and poor concentration. Over time, this metabolic stress further fuels inflammation creating a vicious cycle of low energy and chronic disease.

In addition, many of the seed oils commonly found in processed foods including canola, soybean, and cottonseed oil are derived from crops that have been widely genetically modified and treated with agricultural chemicals such as herbicides and pesticides in commercial production. In the United States and Canada, for example, over 90 % of soybeans, cotton, and canola are genetically engineered varieties, and a large proportion of the oils used in food come from these crops. Some studies highlight concerns about pesticide and processing exposure, especially when seed oils are heated and oxidized, potentially contributing to inflammation and chronic diseases.

A Balanced, Practical Approach to Oils and Energy

Rather than avoiding oils entirely, the goal is to use the right fat in the right way.

1. Choose Heat-Stable Fats for Cooking

For frying, roasting, sautéing, or air-frying:

• Avocado oil

• Ghee

• Coconut oil

• Tallow

These fats are more resistant to oxidation and produce fewer inflammatory by-products when heated.

2. Use Delicate Oils Only Without Heat

For salads, dips, or drizzling:

• Extra-virgin olive oil

• Flaxseed oil

• Sesame oil

Avoid heating these oils, as their beneficial compounds are easily damaged by heat.

3. Reduce Hidden Seed Oils

Most seed oil exposure comes from:

• Fast food (burgers, hot dogs, tacos, fries, pizza)

• Packaged snacks

• Commercial salad dressings

• Baked goods

Cooking more at home and choosing whole foods dramatically reduces intake without strict rules.

4. Support Energy with Anti-Inflammatory Foods

Healthy fats work best when combined with:

• Adequate protein (lean organic meat, wild fish, legumes, quinoa, buckwheat)

• High-fibre vegetables (Brussels sprouts, broccoli, sweet potatoes, potatoes (with skin), leafy greens (kale, spinach), carrots, beets, parsnips, and squash)

• Omega-3-rich foods (fatty fish, algae oil, flax seeds)

This combination supports mitochondrial energy production, reduces inflammation, and stabilizes insulin levels.

Final Thoughts

Seed oils are not inherently toxic, but their widespread use in heated and ultra-processed foods may contribute to inflammation, impaired cholesterol quality, insulin spikes, and chronic fatigue. 

A whole-food, anti-inflammatory diet with thoughtful fat choices supports not only heart health, but also daily energy, mental clarity, and long-term metabolic resilience.

References:

1. https://www.mdpi.com/2072-6643/10/10/1527

2. https://pmc.ncbi.nlm.nih.gov/articles/PMC5422895/

3. https://link.springer.com/article/10.1186/1743-7075-7-11

4. https://www.health.harvard.edu/heart-health/seeding-doubt-the-truth-about-cooking-oils

5. https://www.fda.gov/food/agricultural-biotechnology/gmo-crops-animal-food-and-beyond

Disclaimer
The information provided on this website is for educational and informational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always consult with your physician or another qualified healthcare provider with any questions you may have regarding your health or a medical condition.