In my over-two-decade journey to Balancing my Hormones, eliminating certain cooking oils was one of the most recent changes I made. (I’m not kidding.) Truth be told, I used sunflower and grapeseed oils for years; I had no idea how they, in recent years, have fallen into the “toxic industrial seed oil” category! I always bought non-GMO and organic so I thought it was okay. Until I started diving into the research.
So What are Industrial Seed Oils?
The eight industrial seed oils are Canola, Corn, Cottonseed, Soy, Sunflower, Safflower, Grapeseed, and Rice bran. These oils are highly processed from soybeans, corn, rapeseed, cottonseed, sunflower and safflower seeds.
How did they become so toxic? One word: Oxidation.
During processing, the seeds themselves are heated to extremely high temperatures to oxidize the fatty acids. Unfortunately, Omega-6 (unhealthy) fats are found in oils such as corn, safflower, sunflower, soy and vegetable and products made with those oils. And we have known for years that excess consumption of omega-6 fats can trigger the body to produce pro-inflammatory chemicals. (1)
What’s wrong with industrial seed oils?
There are a few problems with industrial seed oils, all of which play a significant role in chronic inflammatory diseases:

Eating industrial seed oils raises our omega-6-to-omega-3 fatty acid ratios, with significant consequences for our health
Industrial seed oils are unstable and oxidize easily
They contain harmful additives
They’re derived from genetically modified crops
When industrial seed oils are repeatedly heated (as restaurants do in fryers), even more toxic byproducts are created

How are industrial seed oils making us sick?
Industrial seed oils, even if organic or non-gmo, are not healthy. A number of chronic inflammatory diseases have been linked to the consumption of Omega-6 and the byproducts of these oils, in addition to health problems like (2):

Anxiety
Asthma
Autoimmune disease
Depression
Dementia
Diabetes
Heart disease
Hormone Imbalance
Infertility
Inflammation
Intestinal Permeability, “leaky-gut”
Obesity
Osteoarthritis

When it comes to our hormones, did you know that Omega-3 fatty acids (good fats!) are the precursors to properly produced hormones? Therefore, consumption of its counterpart Omega-6 will not promote healthy hormone balance (3).
My Final Thoughts
The best thing you can do for your own (hormone) health and the health of your family is to begin to reduce and eventually eliminate all vegetable oils and margarines from your home. Replace them with healthy saturated fats. I like to bake with coconut oil and grass-fed butter. For stove-top sauteing and stir-frying I opt for avocado or coconut oil. Extra virgin olive oil is my go-to for homemade salad dressing.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335257/
https://pubmed.ncbi.nlm.nih.gov/12442909/
https://pubmed.ncbi.nlm.nih.gov/15385858/