The image below highlights the harmful progression of arterial damage over time due to the consumption of seed oils. While mainstream advice continues to promote seed oils (like canola, sunflower, and soybean oil) for their ability to lower LDL cholesterol, we need to step back and look at the bigger picture: cholesterol is just one marker in a complex system, and focusing on it alone is misleading and potentially dangerous.
Here’s why the consumption of seed oils is a problem and how it leads to the arterial damage shown in the image:
Highly Processed and Unstable
Seed oils are extracted through high heat and chemical processes that render them highly unstable. These oils oxidise easily, which means when you consume them, you’re likely ingesting oxidised fats. Oxidised fats promote inflammation and oxidative stress in the body, both of which are drivers of arterial damage and chronic diseases.
Omega-6 Overload and Inflammation
Seed oils are rich in omega-6 polyunsaturated fats, which, when consumed in excess (as is common today), disrupt the delicate balance between omega-6 and omega-3 fats in the body. This imbalance fuels systemic inflammation, a root cause of many chronic conditions, including cardiovascular disease, and contributes directly to the formation of arterial plaques.
Not All LDL is the Same
The mainstream narrative pushes the idea that lowering LDL cholesterol (the so-called “bad” cholesterol) is essential for heart health. But the reality is far more nuanced. High LDL levels on their own are not inherently bad and can even be protective, especially in the elderly. The real problem is small, dense LDL particles—these are the ones that become oxidised and can penetrate the arterial wall, triggering plaque formation and atherosclerosis. Seed oils contribute to the oxidation of LDL particles, making them more dangerous to your arteries.
LDL Oxidation and Plaque Formation
When LDL particles become oxidised, they are more likely to get trapped in the artery walls, leading to inflammation and plaque build-up. This process is worsened by other factors like high blood sugar, smoking, alcohol, and environmental toxins, which further damage the arterial lining (endothelium), setting the stage for atherosclerosis. Seed oils are a major player in this oxidative environment.
The Problem with Seed Oils in the Diet
Humans have only been consuming seed oils for about 100 years—these highly processed fats are foreign to our bodies and not compatible with our biology. Once they become incorporated into our cell membranes, they destabilise cellular structures, making us more prone to inflammation and oxidative stress.
What’s a Better Alternative?
Instead of relying on inflammatory seed oils, it’s better to turn to natural, stable fats that have been part of the human diet for millennia. These include animal fats like tallow, lard, butter, ghee, and traditional oils like olive oil and coconut oil. These fats are much more stable, less likely to oxidise, and provide essential fatty acids without the pro-inflammatory baggage of seed oils.
So, What’s the Real Culprit?
It’s time to move the focus from the outdated and oversimplified LDL cholesterol narrative to what truly matters: inflammation, oxidative stress, and the health of your arteries. Seed oils promote the conditions that drive atherosclerosis and heart disease. The solution lies in ditching these oils and focusing on nutrient-dense, whole foods and natural fats that support rather than harm your health.
References:
Ravnskov, U. et al. “The Questionable Benefits of Lowering LDL Cholesterol.” Journal of Clinical Lipidology, 2020.
Ramsden, C. E., et al. “The Effects of Linoleic Acid on Inflammation and Atherosclerosis.” BMJ, 2013.
Mozaffarian, D., et al. “Omega-6 Fatty Acids and Cardiovascular Health: Current Evidence and Controversies.” Circulation, 2021.
Parthasarathy, S. et al. “Oxidised Low-Density Lipoprotein: A Role in Atherogenesis.” Journal of Lipid Research, 2010.
