This is my first in a series of health topics. It is meant to be unbiased- but take that with a grain of salt!
Seed oils and their safety has been quite the topic lately. It’s not a simple yes or no.
Seed oils (such as sunflower seed, canola, grape seed) are high in Omega-6 oils- an essential fatty acid that your body needs but does not make. Omega 6 fatty acids needs to come from food or supplementation.
Omega 6 in the body is responsible for regulating brain function, bone growth, metabolism, maintains the reproductive system, supports proper cell function, etc. Omega-6 is considered heart healthy because it lowers LDL (bad cholesterol) and raises HDL (good cholesterol).
Omega 6’s also seem to be related to inflammation in the body, though there is some disagreement whether it CAUSES inflammation or it produces the substrate to fight it. (It seems it might do both) (1)
Omega 6 should be balanced with Omega 3 in a ratio of 1:4 or even 1:2. However- due to the American diet, we mostly fall in the ratio of 1:20. Most of us get enough Omega 6’s and not enough Omega 3’s. (If this is you, talk to your PCP to see if supplementing Omega 3 oils is a good idea.) This ratio balance might be responsible for increased inflammation in the body.
Another issue with Seed oils is how they are processed. They are typically heat derived (and it's not heat stable), chemically derived (with the potential for chemical to remain) or cold pressed. Cold pressed maintains the most stable oil with the most health potential.
Seed oils are often used to fry things (like fries), heated multiple times. The fragility of the oil with heat, especially multiple times, often makes oil rancid and definitely not a good health potential. Fries could instead be fried with an animal fat such as lard. Lard is a very stable fat heated to high temperatures. (The American Heart Association considers Seed oils to be heart healthy and lard to be bad for heart health.)
Chris Kresser has a well written article where he brings up the best highlights of Omega 6’s including- eat as much as possible in real whole foods! (And he brings up that almond flour, a gluten-free alternative, would produce a lot of that unstable cooked Omega 6’s.)
- Most omega-6 fatty acids come from vegetable oils like corn oil, soybean oil, and sunflower oil, which are high in linoleic acid (LA) that can be converted to ARA in the body.
- Arachidonic acid (AA) is the key omega-6 fatty acid that serves as the precursor for pro-inflammatory mediators.
