Which oil is healthiest? My simple answer to this complex question is: flax oil.
My deeper answer is: it depends. What is the use case (salad or stir fry?)? Which fats are you already from your diet? Which oils do you enjoy?
The big reason that I love flax oil is this: it contains very high levels of omega-3 fatty acids, specifically alpha-linolenic acid (ALA). Flax oil is 50-60% ALA, whereas the runner up, canola oil, is far behind at about 10%.
What’s so great about omega-3 fatty acids?
1. We need them. The only types of fats that we MUST get from our diet are the PUFAs, polyunsaturated fatty acids. The abundant ALA in flax oil is in this family. It is essential in its own right but also as a precursor to DHA and EPA (long chain PUFUs).
2. There is a real risk of not getting enough of them from your diet. Omega-3 fatty acids are only highly abundant in a handful of foods. Seeds are your best sources of the shorter chain type (ALA). Fatty seafood and algae oils are the best sources of the longer chain variety of omega-3 fatty acids (DHA and EPA).
3. They seem to be the best fat for cardiovascular health. Besides dialing down your trans fats, the next best thing you can do is replace saturated fats with PUFAs (such as the ALA in flax oil).
Note: Flax oil also has a favourable ratio of omega-6 to omega-3 fatty acids. This science around optimizing this ratio is young and uncertain. One thing is clear: you will convert more ALA to its healthy “daughter” fats (DHA and EPA) if you have less omega-6 around.
Are there benefits to going well above your basic needs for omega-3 fatty acids through supplements (such as fish oils and flax oils)?
The results are mixed. Notably, that the benefits (or lack thereof) depend on your diet. If you eat fatty fish, you are less likely to benefit from adding more omega-3s to your diet. For vegans and other non-seafood eaters, this oil is a must try.
Tips For Using Flax Oil
It is a very heat-sensitive oil so is must be stored in dark at cool temperature and used uncooked (dressings and sauces). It also has a strong distinctive taste, which you may or may not be a fan of. I like it mixed with soy / tamari.