Posted on 09/27/2021 7:16:43 AM PDT by Brookhaven
Abstract
Background: The lung cancer incidence in Chinese women is among the highest in the world, but tobacco smoking accounts for only a minority of the cancers. Epidemiologic investigations of lung cancer among Chinese women have implicated exposure to indoor air pollution from wok cooking, where the volatile emissions from unrefined cooking oils are mutagenic.
Purpose: This study was conducted to identify and quantify the potentially mutagenic substances emitted from a variety of cooking oils heated to the temperatures typically used in wok cooking.
Methods: Several cooking oils and fatty acids were heated in a wok to boiling, at temperatures (for the cooking oils) that ranged from 240 degrees C to 280 degrees C (typical cooking temperatures in Shanghai, China). The oils tested were unrefined Chinese rapeseed, refined U.S. rapeseed (known as canola), Chinese soybean, and Chinese peanut in addition to linolenic, linoleic, and erucic fatty acids. Condensates of the emissions were collected and tested in the Salmonella mutation assay (using Salmonella typhimurium tester strains TA98 and TA104). Volatile decomposition products also were subjected to gas chromatography and mass spectroscopy. Aldehydes were detected using high-performance liquid chromatography and UV spectroscopy.
Results: 1,3-Butadiene, benzene, acrolein, formaldehyde, and other related compounds were qualitatively and quantitatively detected, with emissions tending to be highest for unrefined Chinese rapeseed oil and lowest for peanut oil. The emission of 1,3-butadiene and benzene was approximately 22-fold and 12-fold higher, respectively, from heated unrefined Chinese rapeseed oil than from heated peanut oil. Lowering the cooking temperatures or adding an antioxidant, such as butylated hydroxyanisole, before cooking decreased the amount of these volatile emissions. Among the individual fatty acids tested, heated linolenic acid produced the greatest quantities of 1,3-butadiene, benzene, and acrolein. Separately, the mutagenicity of individual volatile emission condensates was correlated with linolenic acid content (r = .83; P = .0004). Condensates from heated linolenic acid, but not linoleic or erucic acid, were highly mutagenic.
Conclusions: These studies, combined with experimental and epidemiologic findings, suggest that high-temperature wok cooking with unrefined Chinese rapeseed oil may increase lung cancer risk. This study indicates methods that may reduce that risk.
Implications: The common use of wok cooking in China might be an important but controllable risk factor in the etiology of lung cancer. In the United States, where cooking oils are usually refined for purity, additional studies should be conducted to further quantify the potential risks of such methods of cooking.
I'm convinced the next "light bulb" moment in health will center around the use (overuse actually) of vegetable oils.
It has always been know that polyunsaturated oils promote cancer. They were allows to stay in the food supply, because they replaced saturated fats, which were thought to contribute to heart disease.
Now that we know saturated fats DON'T cause heart disease, maybe we should taking a second look at vegetable oils.
Chinese women who stand over woks all day have a high incidence of lung cancer. Heating polyunsaturated fats produces several chemicals that promote lung cancer, and these women breath it in, hence the cancer.
Switching to natural, saturated fats like lard or beef tallow would solve the problem, but then the companies that have billions invested in producing vegetable oils would lose money, so the government can't recommend that.
This is a Pubmed article. It's not some random guy ranting on the internet. The link between cancer and cooking with vegetable oils is pretty clearly laid out.
And, if you go the Pubmed site, at the bottom of the article you'll see several other papers that come to the same conclusion: vegetable oils promote cancer.
Just wear a mask. Problem solved!
What about fry cooks in this country? Thirty years in a McDonald’s? They are not using unrefined Chinese rapeseed oil.
During my year as a fry cook I discovered that it was great for easing sinus congestion and cough. May have been the steam from the carbonated water we poured on the grill to clean it but I don’t think the oil vapor hurt.
Canola oil (refined rapeseed) is disgusting, but unrefined Chinese rapeseed has to be on a level of awful that is off the charts.
Olive oil is the one vegetable oil I think that promotes health.
Avocado is also good. I use it quite a bit.
Many have come to the conclusion that the “low-fat/high-carb” diet was bad advice.
Try “Crime Against Humanity”.
“What about fry cooks in this country?”
What about sailors that worked with asbestos?
It takes decades for the damage done by carcinogens to come to the fore.
Cooked my eggs in bacon fat today.
:-)
I have learned to scour preserved anything to make sure it does not contain canola oil. I cannot abide the taste.
“Thirty years in a McDonald’s? They are not using unrefined Chinese rapeseed oil.”
Rapeseed oil is canola oil.
McDonalds is probably using soybean oil or canola oil. Both contain linolenic acid, which is pointed to as the cancer culprit in this study.
“wear a mask”
Don’t you know those oil fumes go through a cloth mask like a mosquito through a chain link fence?
The comment I've heard about the effectiveness of masks is if you can smell someone's farts or body order right next to you, the masks aren't stopping viruses from getting through.
As far as the deep fryers go, very little of their surface area is exposed, while in wok cooking a large percentage of the vegetable oil is aerosolized. In fact, using a wok at the right temperature a lot of that aerosol is supposed to burst into flame to give the food a smoky flavor or "wok breath" as the Chinese call it.
From another study linked at this article at Pubmed:
“Condensates of volatile emissions from rapeseed [canola] and soybean cooking oils were prepared and found to be genotoxic in short-term tests”
There are literally dozens of research papers at Pubmed that come to the same conclusion: your years as a fry cook may lead you to have cancer one day.
I’m not sure, but I think Olive Oil burns before it gets hot enough for the Wok. Olive Oil is my go-to oil in the kitchen and I only fry in Lard. The good stuff, not the Armor or Hormel brands in the waxed paper.
Potatoes and of course marinated pork fried in Lard is the best. When I was a youngster back in the late ‘60’s McDonalds fried their French fries in lard, they were delicious beyond belief.
And allow us to have good tasting french fries again.
Yes, that’s about the way I look at high carb diets too.
I fry in pig fat, the less refined the better. And if your eyes aren’t stinging from the wood smoke, you’re doing it wrong.
Seed oils are better used as a fuel.
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