The Bad Seed... Oils?

You may be aware of the debate that’s raging in the health-o-sphere regarding the health risks / harmlessness / health benefits (depending on which health influencer you believe) of seed oils.

First of all, what are seed oils? As the name suggests, they’re oils mostly derived from seeds, although soybean oil and corn oil are included in the seed oil discussion. These oils are primarily composed of polyunsaturated Omega-6 fatty acids, and it probably avoids some confusion to think of them this way, rather than as “seed oils,” given that some are not derived from seeds.

Just as an aside, olive and avocado oil are not considered seed oils, as they are derived from the “meat” or “fruit,” not the seeds, and these oils are primarily Omega-9 monounsaturated fats, which have somewhat different properties than polyunsaturateds. They are generally considered “healthy fats.”

A number health influencers have proclaimed seed oils to be not just less healthy than other fats, but outright toxic. But is this really the case?

One of the problems seed oils have had in terms of reputation is that some of the older research done on them was done at a time when they were routinely processed to a point that they contained significant quantities of trans fats. Trans fats are pretty unanimously considered to be unhealthy, and are linked to significant health risks, particularly cardiovascular disease. Although trans fats have been mostly eliminated from seed oil products, the bad reputation of seed oils associated with them continues.

While trans fats are no longer present in “off the shelf” products, there has been a widely-held belief that using seed oils in cooking will cause the production of trans fats because of them being heated. I was under this impression myself, but I have recently become aware of research that counters this.

While it is true that heating polyunsaturated oils can lead to the production of trans fats, it requires high heat for a prolonged period of time. The necessary combination of heat and time might potentially be a factor in a restaurant that doesn’t change out the oil in their deep fryer on a regular basis, but the typical use in home cooking and even in most restaurants would not be sufficient to produce significant trans fats. Really, if you’re eating at a restaurant where trans fats might be an issue, there are probably bigger health risks lurking there anyway!

The trans fat issue aside, there is research showing that people who mostly consume Omega-6 fats do have a small increased risk of cardiovascular disease and overall mortality. But that risk is eliminated when some Omega-3 fatty acids are added to the diet. Furthermore, one study found that the health risks of Omega-6 begin to appear at a ratio of 8 to 1 in relation to Omega-3, and increases as the amount of Omega-6 increases relative to Omega-3.

Because of these findings, some researchers believe that, assuming there’s not extreme Omega-6 consumption, the primary issue is not really with the seed oils, but with a deficiency of Omega-3 fats to balance them.

Because of the proposed toxicity of seed oils, some health influencers have proclaimed that it’s best to replace them with saturated fats, such as beef tallow and butter. The current research just doesn’t back this up. If you exclude the aforementioned trans fat risks that really are no longer an issue, seed oils actually have shown to have fewer health risks than saturated fats.

Ultimately, with adequate Omega-3 intake (for more information, check out this article), the potential risks of consuming seed oils in moderate quantities are small, and they may actually provide some benefits, particularly if they displace some saturated fat from the diet. For most people, other dietary factors such as sugar and refined carbohydrate consumption and various food chemicals used to enhance flavor and/or appearance, are a much bigger health concern than seed oils.

Until next time…

George F. Best, D.C.