Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the practical application of health information. Nutrition. Exercise. Diet. Supplementation. I look at the science behind them, and let you know whether it’s something to consider or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
My oh my oh my! Social media has decided that seed oils is Public Enemy #1. Why? That's an excellent question and so I took it upon myself to try and get to the bottom of this purported health menace. Was this the selective use research to create fear among consumers with the ultimate purpose of gaining notoriety? After all, this appeared to begin on social media platforms of all types a couple of years ago. Or is this a hidden danger to the health of the nation.
What kinds of oils are we talking about? The three most popular appear to be soybean, canola (also called rapeseed), and peanut oil. If you’ve ever deep fried a turkey, peanut oil is the oil of choice because it sustains a relative high heat of 350 degrees for an hour or more. After that it’s corn, safflower, sunflower, cotton seed, grapeseed, and rice bran oils. But the type of seed oil varies whether we’re asking about home consumption, restaurant use, or food manufacturing. That sort of muddles things a bit when it comes to how much we actually get.
What is the purpose of oils such as seed oils in food preparation? More than likely it’s to provide a source for cooking meats and vegetables at high heat. The issue with some of the seed oils that contain polyunsaturated fatty acids (PUFA) is that depending on the type, they may become rancid when stored for a long time. Rancid means the oil or the food containing the oil has been chemically modified either by oxidation or hydrolysis. That leaves the oil or food smelling old and stale. It’s not unsafe; just unappealing. If you’re using one of the oils for salad dressings or cooking, use immediately and then store in the refrigerator.
Let’s get to the heart of the problem. The knock on PUFA’s is that they can have a negative impact on health. We’ve known for over 20 years that we have a PUFA imbalance in our diet. But let’s clarify what we’re talking about.
PUFAs are essential fatty acids which means, we cannot make them. We must get them in our diet. The primary PUFA’s are omega-6 and omega-3 fatty acids. Both are critical to cell membrane structure and function as well as many other important functions in the body. The problem is that we consume them out of balance. What? We’re supposed to have an equal amount of omega-3s and 6s. For the cooking and manufacturing reasons I mentioned earlier, omega-6 intake has grown at a higher rate in American society while omega-3s have decreased as the meat we typically eat, especially beef, no longer contain them and we don’t eat enough cold water fish. The ratio is supposed to be 1:1 to 2:1 omega 6s to omega-3s. The westernized diet has upped that ratio as high as 16:1 omega-6s to omega-3s.
The seed oils themselves are not inherently dangerous. The focus has been on the chemical changes the oils can undergo when they are used to fry foods. There seems to be an increase in aldehyde production. But looking at the research, it’s not clear that aldehydes in reasonable quantities are dangerous. Also, in the few studies that have been done, the focus has been on used oils used for frying foods. The logical question is why not examine the food itself to get a better idea for what a person eats to get the actual quantity and amount of aldehydes produced? How many aldehydes are in the food? No one I know has said “Let’s go to the fast food restaurant and drink the discarded oil!” Have you?
The reason the aldehydes don’t pose a great risk is that there are enzymes that can neutralize the aldehydes for elimination from the body. do their job to maintain a low level of aldehydes in the body converting them into chemicals that can be excreted.
Excess aldehydes appear to be associated with cancer and other degenerative diseases. The oils can also become oxidized which may also increase the risk of irritating the bowel. But in both cases, which is true for other negative effects on the body, it is the volume of such oils consumed that is the issue. I have yet to hear any health and nutrition expert say “Hey! It’s open season on fried foods! You can eat as many of them as you want and because we have these healthier oils to cook them in, go for it!” It’s as ridiculous as it sounded when I just said it.
A couple more points that are not mentioned in the anti-seed oil rants. Some of the seed oils contain phytonutrients. Carotenoids are found in sunflower and canola oils. Polyphenols are found in sunflower, canola, grapeseed, safflower, and even peanut oil. Finally, when it comes to the oils that are actually used in cooking, especially frying, canola, peanut, and palm oil do not have more than 30% PUFA in them. It’s confusing as to why the hazard of seed oils has gained so much traction. Could it be misinterpretation of research?
One of the “experts” suggests that as seed oil consumption increased, the rise in T2D increased a few years later. It’s a compelling graph to view. The problem is that correlation doesn’t equal cause and effect. On top of that, I could make the exact same graph but use carbohydrate consumption instead and come up with the same result. Even more simple? The caloric consumption has increased in the same time frame. Still not there? If you look at the increase in sedentary time over the same time period, you got it, the same correlation is there. So which is it? And yes, the increase in diagnosable CVD increases at the same time parallel to the T2D.
The same expert suggests that the average American gets 80% of their fat calories from seed oils. 80%? In that the average caloric intake (men and women averaged together) is roughly 2100 calories per day, that means 1680 calories would have to come from seed oils. That means 187 grams of fat per day just from seed oils. Does that even make any sense? Even if people consume mostly ultra-processed foods and eat fried foods every day, it just doesn’t make sense without checking any research. When you do check the research, from a variety of sources, you get a total fat intake from all types of fat, of between 47-58%. Does that even come close to 80% just from seed oils? Nope. That’s not the problem.
The problem is that the standard American diet may contain 14 to 25 times more omega-6 fatty acids than omega-3 fatty acids. The majority of those omega-6s? They come from seed oils. That’s back to where I began. It’s not the seed oils, or the carbohydrate or the fat consumption. It is the overconsumption of a nutrient that will lead to problems.
If you’ve seen one of the media posts, be it written or a video, just go on by unless you are a big consumer of ultra-processed foods or fast foods. There is no issue with using sunflower oil in salad dressing or a microgram that might be in a complementary form to stabilize a nutrient. That’s it for this episode. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
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