Topic: Be wary of reclaimed cooking oil

[bhamcurry]

Over the last several decades there has been a lot of focus on the amount of oil and fat used in cooking. Due to that there has been a big switch from lard, butter, and beef tallow to using "vegetable oil" instead.

The problem is that most of the vegetable oil isn't actually made from vegetables. It's made from beans or seeds. The oils are extracted using some very nasty industrial processes.

A recent study has pointed toward these oils being potentially potent carcinogens if they are used at high temperatures. (Don't take my word for it, I will post the link.)

So, please be wary of reclaimed cooking oil, especially if it's from "vegetable oil".


https://medicalxpress.com/news/2019-03-mice-impact-reused-cooking-oil.html

[Peripatetic Phil]

Unless I missed something, it looks as if the research was conducted using solely soyabean oil; in the UK, at least, "vegetable oil" is usually (but not invariably) rapeseed oil.

** Phil.

[bhamcurry]

Unless I missed something, it looks as if the research was conducted using solely soyabean oil; in the UK, at least, "vegetable oil" is usually (but not invariably) rapeseed oil.

** Phil.

yessir. However, the problem with soybean oil spreads to corn, rapeseed, and other seed/bean derived oils - they are basically omega-6 only oils, which is problematic for health reasons. Not doing the same tests with Mazola and Canola oil is a frustrating omission, or it could just be that the researchers felt they didn't need to do so as the oils are so similar?

[Peripatetic Phil]

Not in a position to even try to answer that last question, BHC; not my field, and the only person I knew who could have given a definitive answer sadly died a few years ago.  But I will ask another friend, a professor of human nutrition in New Zealand; she may be able to shed some light on the matter.

** Phil.

[bhamcurry]

thank you, Phil!

[Peripatetic Phil]

Question sent : 

At https://medicalxpress.com/news/2019-03-mice-impact-reused-cooking-oil.html it is suggested that continued re-use of soyabean oil can lead to enhanced rates of progression of cancer in mice; are there any reasons to believe that the same might be true for rapeseed oil, which is far more common in the UK than soyabean oil ?

** Phil (who regularly cooks his popadom in the same old oil week after week after week ...).

[mickyp]

Question sent : 

At https://medicalxpress.com/news/2019-03-mice-impact-reused-cooking-oil.html it is suggested that continued re-use of soyabean oil can lead to enhanced rates of progression of cancer in mice; are there any reasons to believe that the same might be true for rapeseed oil, which is far more common in the UK than soyabean oil ?

** Phil (who regularly cooks his popadom in the same old oil week after week after week ...).

[/quote

As said before popadoms are ok, avoid popyaclogs

[jalfreziT]

I

[Donald Brasco]

I can

[Peripatetic Phil]

The source cited above was just for the layman; the academic source is reputable but I cannot access the full paper without forking out GBP 35-00.  The original abstract reads as follows, but as you will notice, makes no explicit mention of a specific temperature, speaking instead of "deep-frying temperatures"; however, the full text would without doubt be scientifically rigorous in this respect.

Abstract

Deep-frying is a popular form of food preparation used globally and throughout in the United States. Each time dietary oils are heated to deep-frying temperatures, they undergo chemical alterations that result in a new matrix of lipid structures. These lipid products include triglyceride dimers, polymers, oxidized triglycerides, and cyclic monomers, which raises nutritional concerns about associations between these lipid products and heightened health risks. Reports of associations between thermally abused frying oil and deleterious health outcomes currently exist, yet there is little information concerning the effects of thermally abused frying oil consumption and the progression of breast cancer. This study used a late-stage breast cancer murine model and in vivo bioluminescent imaging to monitor progression of metastasis of 4T1 tumor cells in animals consuming fresh soybean oil (SBO) and a thermally abused frying oil (TAFO). Bioluminescent and histologic examinations demonstrated that TAFO consumption resulted in a marked increase of metastatic lung tumor formation compared to SBO consumption. Further, in animals consuming the TAFO treatment diet, metastatic tumors in the lung displayed a 1.4-fold increase in the Ki-67 marker of cellular proliferation and RNA-sequencing analysis of the hepatic tissue revealed a dietary-induced modulation of gene expression in the liver.