Seed Oils

Seed oils often get a bad rap, with claims that we should avoid them at all costs to prevent chronic inflammation and other health issues. But is that really the case?

In reality, it’s unlikely. Let’s take a look at where this idea first originated.

Seed and vegetable oils were widely introduced over 100 years ago. Since then, rates of obesity, cardiovascular disease, coronary heart disease, and other serious illnesses have increased dramatically.

Epidemiological data suggests that people who consume more of these oils tend to be the same individuals who experience the negative health outcomes mentioned.

It’s easy to see how the original conclusion was drawn. However, while epidemiological data can be useful, it doesn’t always tell the full story.

Since then, numerous studies have tested whether seed oils are truly harmful (I’ll link some studies at the bottom for you to read). Fortunately, the data doesn’t seem to support this concern.

One key factor the epidemiological data didn’t account for was the increase in total caloric intake. When researchers studied the effects of seed and vegetable oils on participants in a controlled caloric deficit, the data showed improvements in blood markers associated with the illnesses mentioned earlier across all groups (control group, seed oil group, etc.).

The data suggests that the increased likelihood of these diseases wasn’t caused by seed oils themselves, but by an excess of calories.

This was further tested with groups in the same caloric deficit while manipulating the macronutrient composition (usually keeping protein intake the same). For example: high carb, low saturated fat, low polyunsaturated fatty acids (PUFA); or low carb, high saturated fat (SF), low PUFA; or low carb, low SF, high PUFA. All groups performed similarly, with some occasional positive bias towards the PUFA (seed oil) groups, though these differences were usually statistically insignificant.

The consensus from these more recent studies is that seed oils have a neutral to positive effect, meaning they either had no impact or a slight positive one.

Although the data isn’t conclusive, it strongly suggests that seed oils do not pose significant health risks—as long as you’re not consuming a caloric surplus.