Do Seed Oils Make You Sick? Why Some Doctors Say Seed Oils are Heart Healthy When They’re Not

Seed oils are ultra processed and pro-inflammatory foods that are linked to heart disease and other chronic conditions. The science is becoming clearer every day, yet many physicians and seemingly reputable sources still suggest that seed oils are healthy? So do seed oils make you sick…or not?

After posting a REEL on Instagram on the dangers of seed oils, a cardiologist commented that it was the “dumbest thing he has heard” and went on to say that “…science clearly states that seed oils actually reduce cardiovascular mortality and improve health.” 

Comments like this highlight why people are losing trust in each other. Insulting comments don’t champion the quest for open dialogue and pursuit of truth. Also, restating something generic like: “The science says,” doesn’t say much. We are always open to dialogue and debate, but with compassion and curiosity, not with animosity and aggression. 

So do seed oils make you sick? Let’s pause and consider why this cardiologist and some of his colleagues still think that seed oils are “heart healthy.” 

Science is an ongoing inquiry. It’s constantly evolving and discovering new things. Science also needs context. Research studies are carried out in specific environments that can’t always be translated out into the rest of the world. The world is complicated, and health in particular is very complicated. It’s important to consider the strengths and weaknesses of the studies we rely on to make health decisions.

We encourage our community to challenge the assertion of authority, even our own. We’re just like many of you: learning every day while trying to do best by our families and loved ones. We all want to live with more energy, vitality, peace, and happiness.  

We are dedicated to presenting the best possible information, and we are always open to dialogue and questions. When new data arises, we reconsider. Rest assured that if we’re incorrect or if our information is outdated, we’ll be the first to admit, “we are wrong!” 

In this case, we still hold our stance that seed oils pose a serious danger to our health and there are plenty of reasons to avoid them. 

The two biggest pieces to understand are that research requires context and close reading and that doctors are influenced by the culture they practice in. And to put it right up front: big food companies have A LOT of influence in our culture’s popular understanding of health and nutrition. Big Food cares about profits, not our health, and they use dishonest tactics to sell more of their products. Unfortunately, many of us, including doctors, are still being duped by these companies. 

do seed oils make you sick vegetable oil

Research Requires Context

No matter what topic you are questioning or taking a stance on, you’ll see research studies being waved on either side. We link to research studies often in our blogs. It’s important to understand that their research studies don’t happen in a vacuum. There are human beings creating them and participating in them, and that means there is room for error and nuance. 

Medicine and health care are complicated fields. There are many different players with different interests: doctors and patients of course, but also researchers, pharmaceutical companies, technology companies, medical schools, manufacturers, insurance companies, and more. If you didn’t notice while reading that list, many of those players are businesses. They need to make a profit. Now, needing to make a profit doesn’t necessarily mean that you are evil or trying to harm people, but it does skew your motives. 

Who is funding the research?

What gets researched, and what research gets funded is a good place to start. By looking at who is funding the research on seed oils, you can quickly start to identify some conflicts of interest. For example in this study, the head researcher, William Harris, was directly funded by Monsanto! Monsanto (now owned by Bayer) was an agrochemical and agricultural tech company that produced corn, soy, canola, and cotton which are all used to make seed oils. 

The American Heart Association backs the “research” and makes recommendations in their “respected” journals. This study in a famous journal (one of the many journals from the American Heart Association) was sponsored by Unilever who just happens to make margarine and mayonnaise from seed oils. In both of these examples, the funders had significant stakes in the outcomes of those studies which would impact their sales. A funder with a strong preference for a study to go a certain way does not bode well for the reliability of the study. 

Most medical journals have unethical relationships with pharmaceutical companies and only recently have started asking authors about conflicts of interest. If you want to dive even further into this, read the incredibly well-researched and fascinating book, The Empire of Pain: The Secret of the Sackler Dynasty, by Patrick Radden Keefe. It clearly shows how Big Pharma, namely Purdue Pharma, impacted physicians’ wide approval (and sometimes abuse) of opioids through strategic marketing, campaigns, and sometimes out-right lies supported by “science”, all driven by a desire to increase profits. 

What are the researchers measuring?

Sometimes, researchers miss the mark on what to look at in their studies. For example, this study is often quoted as evidence to increase our consumption of linoleic acid. It looks compelling, but not so fast. They measure the serum (blood) levels of linoleic acid vs cardiovascular death over 22 years. They found that the higher the level of blood linoleic acid the less deaths from cardiovascular disease. Seems like a great finding. However, we know that linoleic acid is not bad in itself. It is oxidized linoleic acid that causes the problems. So, measuring the levels of linoleic acid is a moot point. The study is measuring the wrong thing.   

It’s much like saying, firefighters cause fires because they are always at the scene of a fire. Rather, current research suggests that it is more useful to measure oxidized linoleic acid in the fat through adipose biopsies. You can easily see that blood levels of linoleic acid don’t equal oxidized linoleic acid in adipose biopsies. Two totally different measurements. 

How is the research being conducted?

One popular argument against the, amongst physicians, is that “all” the studies which show that oxidized linoleic acid is proinflammatory is only seen in animal studies such as in mice and bunnies. Yes, we agree that being human is different from being a mouse, however, the basic biology/pathology is often reliably deduced from animal models. 

It is very expensive and time consuming to do human, double-blind, randomized control studies (the gold standard of studies in the scientific community). This is the only type of study that can say something CAUSED something else. There are ethical concerns with this type of study when it comes to our bodies. Nutrition studies may impact a person’s health, fertility, or lifespan. We can’t ethically randomize a group to eat something that will potentially harm them. Would you want your kid to be in a study group that is fed junk food vs another group that is fed nutrient dense whole foods?

This argument is also hypocritical since they use animal studies to support their claims that seed oils are healthy. You can’t have it both ways. 

Much of nutritional science is based on observational studies. It is important to understand the limitations of observational studies. We are only able to detect a link, NOT A CAUSE, nor a direction, nor a potential third variable. For example, eating junk food is linked to obesity. Is it the junk food that causes obesity or does obesity cause one to eat junk food (which direction is it)? Is it both or is there another thing that we haven’t considered (third variable possibility). You get the picture. But observational studies are still helpful and can help us understand the relationships between foods and health.

Misinterpreting data

Probably the most popular argument by physicians that are pro seed oils is that linoleic acid (omega-6) fatty acids are essential. This is true. However, the poison is in the dose. We love cinnamon, however, we don’t down a whole bottle because that is not only silly, but lethal! This is a misinterpretation of the truth that we need omega-6 fatty acids. They are essential, but in moderation and in the right ratio to omega-3 fatty acids

Linoleic acid is the primary concern with seed oils. It is a highly unstable type of Omega 6 that when processed and heated, breaks down into toxic byproducts that are known carcinogens and are pro-inflammatory in our body. The fact that seed oils are high in linoleic acid is most concerning. It is not the linoleic acid, rather it is the oxidation of linoleic acid. When linoleic is oxidized by both processing the seed into an oil outside the body and oxygen (lipid peroxidation) inside the body, many toxic byproducts are formed (toxic aldehydes). These toxic aldehydes, especially, HNE are proinflammatory thus strongly linked to chronic disease and even cancers. 

Another argument is that seed oils lower LDL and thus reduce cardiovascular disease. Yes, seed oils do reduce total LDL. But, they increase one little thing, death. Here is a direct quote, “There was a 22% higher risk of death for each 30 mg/dL (0.78 mmol/L) reduction in serum cholesterol (LDL). The Minnesota Coronary Study that was intentionally hidden for many years was finally published in 2016. Why might this be? LDL (“bad cholesterol”) is very nuanced. The latest research clearly indicates it is not LDL that causes heart disease, rather it is oxidized LDL that does.

Also, LDL has two main types. One type is fluffy, buoyant LDL which does not cause heart disease. It is neutral and represents about 80% of the total LDL that is measured. The other type of LDL is small dense LDL. This type does cause inflammation, atherosclerosis, and ultimately heart disease. It represents about 20% of the total LDL. When we get our cholesterol checked, how do we know which type we have more of? That is for another discussion. The point is that there is so much nuance that must be considered. Any quick conclusion should be considered closely. 

scientific researcher with microscope in lab do seed oils make you sick

Doctors are Influenced by the Larger Culture

We tend to idolize doctors as people who always know best. Remember, I’m also a physician. Medicine is an incredible profession, and most doctors are well-educated, upstanding people who care deeply for their patients. But, it’s important to remember that they are human beings with weaknesses, susceptible to influence and marketing just like the rest of us. And remember, nutrition isn’t prioritized in medical school. Food may not even be a central or important part of a doctor’s life.

Doctors have little time and training to read new studies

Most doctors don’t have the time to read full research papers in context. Instead, they rely on the abstract (that short summarizing paragraph at the beginning of the study) which is the authors’ interpretation of the data and often lacks nuance. That’s probably true for most of us. 

It makes sense that doctors don’t spend a great deal of time reading articles in medical journals in depth. They are not scientists but practitioners and are not trained to critically read scientific papers. These papers are dense! Sometimes it can be difficult to even understand a food label, let alone interpret scientific jargon. 

Further, doctors attend the same major conferences for their respective fields which are more often than not sponsored by large pharmaceutical companies or agriculture companies, potentially giving those companies influence in the conference focus and content or simply unconsciously encouraging doctors to trust them. This happens often, across many fields, like in the case of the opioid epidemic, where Purdue Pharma held over 40 national pain-management conferences, influencing physicians’ opinions on pain management, and led to the opioid epidemic. 

Doctors are susceptible to marketing and influence

Our culture’s view on nutrition is influenced by many players, including lobbyists who affect food policy, marketing by food companies, and our American obsession with a “quick fix”. And again, big food companies have a big influence on nutrition research. Doctors are barely taught anything about nutrition in medical school, and they are just as susceptible as the rest of us to marketing and influence in our larger culture.

When does new research enter practice?

It’s worth noting that there is a lengthy lag between when new research comes out and when it goes into practice. So, even if there are robust studies coming out, it will take 10-20 years for that new information to be put into practice. It’s even harder to undo practices that are later proved to be ineffective or unhealthy. “Vegetable” oils have been promoted as heart healthy for years, and now we are having to undo that story.

do seed oils make you sick pediatrician heart exam child

Do seed oils make you sick? In Summary:

Big food companies have a lot of weight to throw around in the world of nutrition, and doctors (and even scientists!) are not immune to their influence. Thankfully, we do have scientists, independent researchers, and doctors that challenge the narratives these companies are pushing. 

We aren’t trying to cut down doctors or discredit their hard earned experience and knowledge (remember I’m a physician too), but we are aware of the many powerful factors at play in the narrative of nutrition. If your doctor still believes that seed oils are healthy, be curious! Offer to share your resources and have a discussion. We are in a new time when scientific studies are as available to patients as they are to doctors.

It can be a wild world out there, trying to figure out what is healthy and how to feed our family. But just remember to choose whole foods and stick close to what our ancestors ate (definitely no seed oils!): healthy fats, whole fruits and veggies, pastured meats and eggs, grass-fed dairy. Cook at home when you can, and remember to ENJOY your food!


Our promise!

We are dedicated to doing the hard work to present the most accurate information possible. We’ll change our viewpoints as new information comes along. We understand that you may not have the time to dig into the science (and maybe neither does your doctor!) We encourage you to take the time to educate yourself about your food choices and to be open to having conversations with others, even your doctor, with compassion and curiosity. 

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Seed Oils Like Vegetable & Grapeseed Oil Are Damaging Your Health!

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