If you’re (wisely) seeking to avoid trans fats, olive oil is your best choice among cooking oils. Extra virgin olive oil contains virtually no trans fats, and refined olive oil has 0.5% or less.
Solvent-extracted oils (e.g., canola, soybean, etc.) must be heated to high temperatures to help the solvent evaporate, a process that creates trans fats. No olive oil is solvent-extracted. As a result, even refined olive oil contains as much as seven times fewer trans fats than canola oil and as much as four times fewer trans fats than soybean oil.
| Oil Type | Trans Fat Content (%) |
| Extra Virgin Olive Oil | < 0.1% |
| Refined Olive Oil | < 0.5% |
| Soybean Oil | 0.4 - 2.1% |
| Sunflower Oil | 1.1% |
| Canola Oil | 1.9 - 3.6% |
Source: The Nutrition Source, Harvard T.H. Chan School of Public Health
Note: Trans fats do not have to be disclosed on the nutrition facts label of any of the oils listed above because FDA set the threshold at a higher level, allowing all products to declare “0” grams even though trans fats are present in varying amounts in cooking oils.
There’s also no need to be concerned about producing trans fats when cooking with olive oil. A study published in the International Journal of Fats and Oils involved frying potatoes in olive oil eight times at 356°F for 15 minutes. The oil was sampled after every use, and even after eight uses, fewer than 0.002% trans fatty acids were formed.