This post is a modified version of a newsletter that I wrote. Every week I share nutrition insights and tips, along with a recipe and recommendations for things to read, listen to, or try. I would be stoked if you signed up: sign up here.

Deep dive on healthy and unhealthy cooking oils

TL;DR Replace high omega-6 vegetable oils and shortening with healthier alternatives like avocado oil, extra virgin olive oil, and coconut oil. Learn the smoke point of these oils so you can use them the right way and keep them healthy. Recommendations for that below. 

healthy cooking oil: olive oil vs vegetable oil
Olive oil vs vegetable oil: which should you use?

Let’s cover which oils you should avoid and why, and then we’ll move on to which oils you should use and how…

Unhealthy cooking oils you should avoid

Many of the oils we use often are proven to be harmful, but these oils are common in a Standard American Diet (SAD) and may be difficult for some people to give up. 

Let me cut to the chase…

You should avoid: vegetable oils and partially hydrogenated oils like some margarine and shortening.

Here’s the why…

  1. Vegetable oils and hydrogenated oils (aka heavily processed seed oils) are high in omega-6 fatty acids (thought to be pro-inflammatory) and lack nutrients.
  2. Partially hydrogenated oils are high in trans fats, which are known to be bad for your health and are even linked to cancer. 
healthy and unhealthy oils based on fatty acid content
Breakdown of dietary fats and fatty acid content (source) Vegetable oils like sunflower and soybean oil which are usually heavily processed and high in omega-6 fatty acids.

The deets on vegetable oils and omega-6

Omega-6 fatty acids are actually an essential nutrient your body requires, but most of us are getting way too much.

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It is hypothesized that the body needs a balance of omega-6’s to omega-3’s. We evolved eating a ratio of about 1:1, while the ratio today is closer to 16:1…

Most of us eat too few high omega-3 foods (like fatty fish) and way too much omega-6 food (vegetable oils, fried food, etc.).

Omega-6’s are thought to be pro-inflammatory and omega-3’s are thought to be anti-inflammatory. If we’re out of balance the body is more likely to be in a state of chronic inflammation (bad).

So, replacing vegetable oils in your cooking can help.

There are many other hypotheses for the negative impact of vegetable oils, like the oxidized linoleic acid hypothesis, and the generation of hydroxynonenal (HNE) which is linked to neurodegenerative diseases, diabetes, and inflammation…  

“When heated, omega-6 PUFA-rich vegetable oils generate a substance known as hydroxynonenal, which researchers now believe plays a key role in cell degeneration and cell death” —

Note that stir frying / frying with some vegetable oils is even known to increase the trans fat content, and will even increase slightly every time it’s used (source: NIH). 

…so, on to trans fats and hydrogenated oils. 

The deets on hydrogenated oils and trans fat

Partially hydrogenated oils like some margarine and shortening are very high in trans fats. Fully hydrogenated oils do not contain a meaningful amount of trans fats, but are still not recommended. If you have to use shortening or margarine, see if you can find the fully hydrogenated kind.  

Trans fats are a type of unsaturated fat that occurs naturally in very small amounts in some foods (meat and milk fat). BUT, almost all of the trans fat we consume is generated during the processing of food.

Trans fats are not even on the GRAS (generally recognized as safe) list that the FDA puts out, and there are a lot of other harmful “foods” on that list. The FDA says there is no safe amount of trans fat to consume. (From the FDA)

“Trans fat is considered the worst type of fat you can eat”

Mayo Clinic

These fats are known to not only increase your “bad” cholesterol, but also lowers your “good” cholesterol. (More on cholesterol at a later point, this is a meaty subject. Good and bad is over-simplifying.)

Trans fats are linked to type 2 diabetes, heart attacks, stroke, and obesity.

Technically your food may still contain trans fats even if it says there are none. If it contains less than 0.5g of trans fat the product can claim 0 grams…

The trans fats can add up quickly on products that claim they have none, look out for “partially hydrogenated oils” on your labels. 

Ok, on to the good stuff! What oils are good to use, and how should you use them. 

Using healthy cooking oils the right way

Even with the good fats, you need to know the right way to use them. Really, the most important thing to consider is the smoke point of the oil you’re using.

When oil is heated past its smoke point, the oil begins to mix with oxygen to create free radicals. Free radicals are molecules that can damage your DNA and are known to be linked to cancer (wiki). 

Here is a quick review of some healthier options you can use with low, medium, and high smoke points…

Low smoke point oils

These oils are best used for salad dressing, topping a soup, or very low heat cooking.

  • Walnut oil
  • Flaxseed oil
  • Grass fed butter

Medium smoke point oils

These oils are best for low to medium heat cooking, like baking and medium heat sautéing. 

  • Extra virgin olive oil 
  • Extra virgin coconut oil

High smoke point oils

These are best for high heat cooking, like high heat sautéing, stir frying, and frying. 

  • Avocado oil 
  • Ghee
  • Refined coconut oil

I put a little cheat sheet together that you can use below. Feel free to print this out or download it to your phone for future reference.

Cooking oil and butter smoke points

And, if you want to learn more about this, I’ve seen this book “The Big Book of Health Cooking Oils” recommended. I usually like to use, and you can find a list of my favorite books here, but this one wasn’t available on Bookshop. 

Also, speaking of oil if you haven’t checked out my framework for creating salad dressings, check that out!

A recipe

Fall Sweet Potato and Pomegranate Salad

We’re moving into the fall season, so I wanted to throw together a fall inspired recipe

This salad uses some nutrient power-houses: sweet potato, pomegranate, walnuts, quinoa and spinach.

These ingredients are packed with fiber, iron, calcium, vitamin A, vitamin C, and B vitamins and more.

Checkout the full recipe here


  1. This Doctor’s Kitchen podcast is on mental fitness and has some great reminder and techniques you can use to keep your mind and mental health in good shape. 
  2. The Happy Not Perfect App was featured in the podcast and I’m starting to give it a shot this week. This app is one way to do some mental fitness of your own. Hit me up on the socials or email me back if you give it a try.

Thank you so much for reading! If you’re not already signed up for the newsletter, I’d appreciate you checking it out. You can sign up here. And share with a friend 🙂

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