The main ingredient in seed oils causes liver disease and liver cancer
PUFA (linoleic acid) is hepatotoxic and carcinogenic; MUFA/SFA are not (2023)
Context
This is a summary of an online commentary from the excellent blog To Extract Knowledge from Matter on two recent papers drawing attention to the harmful effects of linoleic acid (LA), the main ingredient in seed oils [1].
I’ve written at length about different kinds of fat, their origin, benefit, and potential to cause harm. In essence LA when delivered in seed oils has the potential to cause significant harm, and I think it may have been the primary cause of my heart disease.
This commentary provides additional insight into the ways that too much LA harms the human body.
Objective and results of the study
There are two papers covered, the original and a short commentary. In the original paper, the authors studied mouse models and human clinical samples to investigate the way in which LA affects liver disease and liver cancer.
“LA is a potent toxin and can itself cause the progression of liver disease from non-alcoholic fatty liver disease (NAFLD) to Non-alcohol related steatohepatitis (NASH) through cirrhosis and ultimately to liver cancer”
Why are the results of the study interesting?
A couple of things are revealed, namely the role of LA in the progression of liver disease plus the implications of an underlying role for LA in other illnesses. There are four main takeaways:
LA is a potent toxin and can itself cause the progression of liver disease from non-alcoholic fatty liver disease (NAFLD) to non-alcohol related steatohepatitis (NASH) through cirrhosis and ultimately to liver cancer
None of the other types of fat tested were fattening for the liver or caused liver cancer
LA causes liver disease progression by killing cells of the immune system and creating long-term (chronic) inflammation
The immunosuppressive and inflammatory effects of LA have the potential to implicate it in a number of infectious and chronic diseases
How do the results of the study help me to understand health and longevity?
Avoiding harm is probably the first thing we should do when trying to live a long and healthy life. My research to date has convinced me that the high amounts of LA in seed oils are harmful, and more than likely the cause of my heart disease.
The information in the papers described adds to my belief and provides more information about how LA exerts its harmful effects.
I’m staying away as much as possible from seed oils.
“The immunosuppressive and inflammatory effects of LA have the potential to implicate it in a number of infectious and chronic diseases”
Study outline
Metabolic changes observed in NAFLD-promoted liver cancer were investigated using a series of different mouse models of NAFLD and liver cancer, and then confirmed using human samples.
Details can be found in the original paper [2] and the short commentary [3].
References
PUFA (linoleic acid) is hepatotoxic and carcinogenic; MUFA/SFA are not http://haidut.me/?p=2366
Ma, C., Kesarwala, A., Eggert, T. et al. NAFLD causes selective CD4+ T lymphocyte loss and promotes hepatocarcinogenesis. Nature 531, 253–257 (2016). https://doi.org/10.1038/nature16969
Shalapour S, Karin M. Fatty Acid-Induced T Cell Loss Greases Liver Carcinogenesis. Cell Metab. 2016 May 10;23(5):759-61. doi: 10.1016/j.cmet.2016.04.018. PMID: 27166937