In a deviation from the previous articles in this series, in this piece I plan to analyze a paper Dr. Paul Saladino cited in a recent podcast episode (link) with Dr. Chris Knobbe titled, “The Omega-6 Apocalypse, are seed oils to blame for diabetes, heart attacks, and chronic disease?” In the episode, Dr. Saladino referenced a 1993 paper that assessed the relationship between adipose fatty acid concentrations and coronary artery disease, titled, “Can linoleic acid contribute to coronary artery disease?” My interest was piqued, so I read the paper and have briefly analyzed it in this article.
On to the paper: the researchers assessed the correlations between the concentrations of fatty acids in adipose tissue and platelets and two measures of coronary artery disease, specifically myocardial score and extent score, which are based on coronary angiography. The r values typically fell between -0.3 and 0.3—in short, they were weak or nonexistent correlations (i.e., of minimal clinical significance). Additionally, when the researchers adjusted for covariates, the association between linoleic acid in adipose tissue and the extent score became statistically insignificant, though the association between linoleic acid and the myocardial score remained significant (r = 0.20, p < 0.05).
And if you look at the data tables, then you’ll see a hodgepodge of findings, including a positive correlation between palmitic acid and triglycerides in men (r = 0.31, p < 0.01) and no statistically significant correlations between linoleic acid and either BMI or HDL in men and women. Point being, one could interpret the data set in a number of different ways, yet the most intellectually honest appraisal to me seems to be that there aren’t clinically meaningful correlations in any direction for any of these fatty acids with coronary artery disease or CAD risk factors. My humble recommendation is to not use this study to try to demonize linoleic acid.
Note that I’m not advocating that people chug bottles of soybean oil with reckless abandon. Rather, I simply hope to show that this study doesn’t seem to lend much support to the hypothesis that linoleic acid causes coronary artery disease. It seems to me that, at best, the findings of this study could be used to generate testable hypotheses. Perhaps most important of all, however, this study seems to be an example of why it’s important to 1) read more than the paper’s abstract and 2) review the data in order to determine the degree to which the findings are clinically meaningful.
That’s all for this installment. If you have topics you’d like to see discussed in future installments of this series, then leave me a comment to let me know.
Hodgson J, Wahlqvist M, Boxall J, Balazs N. Can linoleic acid contribute to coronary artery disease? The American journal of clinical nutrition. 1993;58:228-234. doi:10.1093/ajcn/58.2.228