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 swear I didn’t know people could still buy lard. I’ve skimped by with saved bacon grease, but I’ll have to look harder. TYTYTY!
I don’t cook with any of those kind of oils.
After cooking popcorn in my microwave the odor
from the refined canola oil is completely unbreathable.
May try peanut oil next.
Butter!
Rapeseed/canola is unique. Voce are used to extract it from rapeseed. Then the poisons are removed via other processes.
Sounds healthy to me.
Chinese using unrefined rapeseed makes me giggle.
Sarc needed?
Heating does bad things to olive oil. Should not use it in anything but low temperature cooking.
Seed oils are poison.
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.
People with Asian and American Indian blood have a high incidence of ALDH mutation (Asian flush) from ingestion of alcohol and fructose. It leaves us with elevated aldehydes which predispose us to disease. It seems that wok cooking with vegetable oil exacerbates this condition.
Wow, now THAT was an informative post. Hmm...
There’s risk in breathing carcinogenic fumes. What about eating food cooked in these oils at high temperature? Is that safe ?
All vegetable oils polymerize with exposure to oxygen and heat. At varying temperatures.
Virgin olive has a lower smoke point but pure/ filtered olive has one of the highest smoke points and is great for frying.
Virgin oils are best for low temp cooking or used cool.
Rapeseed oil is mustard seed oil. Rapeseed oil until recently, was an industrial oil that was used for paints and marine purposes, can be applied to surfaces underwater or something along those lines.
Canadian agricultural modified the mustard plant to reduce the mustard component and it is now safe, but we all know how that works. (They were looking for a crop that grew fast in short season high latitude climates.)
I will not use canola oil and will not buy a product if it contains it. Any claimed benefit (It has omega3 oils) is eliminated by they oil extraction method, and it also goes rancid very quickly. Won’t use.
The term “vegetable oils” should be in quotes. No vegetables are harmed in the making of these oils...they are chemically extracted from seeds - grapeseed, soybeans, cottonseed, etc. - originally as a way of finding use for those “waste” products. I read once that if you step on something and it leaves an oil spot (as olives or walnuts would do), THAT is a legit source of an oil; if it has to be chemically extracted, you should avoid it.
“And allow us to have good tasting french fries again.”
I’ll never forget the time circa 1991 when I picked up fries at McDonald’s in Berkeley, CA, and immediately tasted something different and inferior to the McD’s fries I had known and loved for years. Something was off. A few weeks later I saw some blurb indicating McD’s had announced completion of its transition to a new, healthier vegetable oil blend. When I hear youngsters say that McD’s has great fries, etc. I shake my head. They used to, but haven’t for 30 years (unless you’re in one of the countries where they’re still using beef tallow). Sadly, they’ll never go back to beef tallow in the U.S.. Too many veggie/vegan/Hindu weirdos would cry foul now if there were beef in their fries.
Costco sells 20 lb boxes of lard.
Chinese have their really cheap oils - but the vast majority of the population there eats the same refined, bleached, deoderized vegetable oils as Americans do. Soybean is the largest, same as the USA
My thoughts exactly. Criminal.
“There’s risk in breathing carcinogenic fumes. What about eating food cooked in these oils at high temperature? Is that safe ?”
Dr. Robert Lustig & Tucker Goodrich both discuss this on Youtubes.
The answer seems to be: nobody knows.
Could a primary causal factor of their cancer be not from the oil but the type of pan they were using? I know a lady who used a type of crock pot made from China. She used it almost exclusively in cooking her daughter’s meals until the daughter tested positive for lead poisoning. The state health agency tested everything in her house and found the culprit was the crock pot. The materials used and the way it was constructed caused it to be dangerous.
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