Unfortunately, studies show that long-term consumption of oxidized vegetable oils like canola may lead to chronic inflammation, heart disease, and even liver dysfunction. This could be partially due to its high omega-6 content, which can be toxic when consumed excessively.

And it’s not just canola oil, here are a few other harmful oils to watch out for:

• Soybean Oil – Highly processed and very high in omega-6s.
  
  
• “Vegetable Oil” – Typically a mix of low-quality oils (like soybean, corn, or cottonseed) that are refined and oxidize easily.
  
  
• Cottonseed Oil – Contains pesticide residues and is often hydrogenated, which increases its trans fat content.
  
  
• Sunflower Oil (refined) – Though it sounds healthy, it’s toxic at high heat and oxidizes quickly.
  
  
• Grapeseed Oil – Very high in omega-6s and usually solvent-extracted
  
  
• Palm Oil – Increases the risk of cardiovascular disease.

To avoid these harmful oils, you’ll need to skip most ready-to-eat supermarket foods, as they are the primary source.

Now, what about olive oil? It’s a fundamental part of the Mediterranean diet, often regarded as the healthiest diet in the world.

And yes, it is extremely healthy, mostly because of its high content of monounsaturated fats and powerful antioxidants. However, when it comes to high-temperature cooking, olive oil isn’t ideal. With its relatively low smoke point, olive oil can oxidize under heat and produce free radicals. Over time, this could have a negative impact on your health.

If you plan to consume olive oil, avoid heating it and opt for extra-virgin olive oil instead.