Are Seed Oils Bad? – Rust Nutrition Services – Chew The Facts®

Are seed oils bad for you? The scientific evidence about soybean, canola, and corn oils show they support heart health. Yet this information seems to fall on deaf ears because a few years ago, perhaps fueled by the Paleo and carnivore diet trends, seed oils were deemed to be “bad”. These myths were strengthened by the likes of Joe Rogan and other social media influencers.

Consider this your reminder to be careful where you get your nutrition information, and remember to be a critical thinker.

Social Media Misinformation and Disinformation

Social media posts claims that seed oils (or n-6 Polyunsaturated fats) “promote inflammation” (oxidative stress) continue to pollute social media. Many young people especially are consuming this media and going along with the convincing posts. Let’s take a look at the facts on dietary fats, and also put into perspective the small amount of fat that is recommended for consumption. The DASH Diet meal plan limits fat to about 30% of total calories.

Trendy social media influencers who tout high protein, high fat diets, seem to be aiming to convince you that “we” (registered dietitians or other health professionals) are telling you that “fat is bad”, and you should avoid fat.

These misperceptions suggest that dietitians are recommending fat-free dietary plans. This has never been true.

On the other hand, carnivore friends of Joe Rogan are recommending up to 60 percent of calories from fat.

A Quick Nutrition Lesson about Fats

There are two basic types of fats in our diet: saturated and unsaturated. Saturated fats refers to the hydrogen in the fat molecules. These types of fats are “saturated” with hydrogen. Unsaturated fats have less hydrogen, and there are two types of unsaturated fats: Polyunsaturated and Monounsaturated.

Polyunsaturated fats (PUFAs) are a source of the two “essential fatty acids”, α-linolenic acid (ALA) and linoleic (LA) acids. By essential, I mean we need them to live. Your body can’t make them and therefore you need to get them from food. These essential fatty acids support brain development, control inflammation, and are needed for blood clotting.

PUFAs are divided into two groups: omega-3 and omega-6. It’s important to understand that all fats have a combination of these types of fatty acids, with varying amounts of saturated, polyunsaturated and monounsaturated fatty acids.

What Does the Science Say about Diet and Fat?

Epidemiological and clinical trial evidence indicates that n-6 polyunsaturated fatty acid (PUFA) intake is cardio-protective. This means that oils like soybean, canola, and corn, help PROTECT our heart health. There is quite a bit of evidence that shows this.

That’s why, for people with heart disease, or a family history of heart disease (like myself), I generally recommend replacing some of the saturated fat (butter, animal fats, coconut oil, palm oil) in the diet with PUFAs. Clinical trials show that a higher intake of unsaturated fat from plant sources improves major cardiovascular risk factors.  In fact, clinical trials show that even increased intake of n-6 PUFA (linoleic acid) does not increase markers of inflammation or oxidative stress.

Now, unlike the views of my carnivore-diet-counterparts who consume butter (a saturated fat) by the stick, I know that portions matter. You shouldn’t be eating butter by the stick, nor should you be drinking vegetable oil. You can, however, use it in your cooking, baking or on salads. This can be visualized by adding a 1-2 teaspoons of fat to each meal, or generally consuming 2 tablespoons or less of added oils a day.

Seed Oil Confusion

So why are all of these un-credentialed people on social media yelling at you about seed oils? Good question! My theory is that this trend stemmed from the carnivore and high fat, low carb (HFLC) diet tribes.

I subscribe to making recommendations based on the totality of the scientific evidence, and in terms of improving overall public health. These folks generally recommend lard, beef tallow, and butter as a primary fat source. They believe that “omega-6 oils cause inflammation, therefore all omega-6 fats should be avoided”.

It’s misguided to translate the personal philosophy of fringe diet gurus into public health messaging. Share on X

Instead, the evidence points to recommending the consumption of sufficient amounts of both omega-6 and omega-3 fatty acids as both types of fatty acids promote health. 

As always, the dose makes the poison. Too much of any source of fat, is not a great choice for most people. Why? Because if fat is contributing a huge caloric load, they won’t have room to consume other fiber- and nutrient-rich foods (like vegetables, whole grains, fruit).

Here’s the lowdown on seed oil science:

• Population studies show diets higher in linoleic acid are associated with lower risk of heart disease, coronary artery disease, diabetes, and overall mortality.
• Clinical and observational studies show that intake of linoleic acid, the omega-6 PUFA in seed oils, does not increase inflammation or oxidative (molecular) stress. In fact, population studies often show that higher intake of this omega-6 is associated with reduced, rather than increased, inflammation.
• Many seed oils have a high omega-6:omega-3 ratio, but it varies. Studies show no impact on markers of inflammation and oxidation with the use of soybean oil, for example. Health authorities no longer consider the omega-6:omega-3 ratio to be a useful measure of diet quality.
• It is difficult to do large-scale human studies isolating omega-6 fatty acids. However in studies with nonhuman primates, LA-rich vegetable oils decrease markers for heart disease compared with saturated or monounsaturated fatty acids. More recent meta-analysis suggest that intake of omega-6 fatty acids, like linoleic acid, does not increase oxidative stress.
  

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