3 ms·

Refined seed oils contain polyunsaturated fats (and more specifically, omega-6 polyunsaturated fats, and more specifically yet, linoleic acid) in far higher con

by dilap 5y ago

Refined seed oils contain polyunsaturated fats (and more specifically, omega-6 polyunsaturated fats, and more specifically yet, linoleic acid) in far higher concentrations than traditional foods. I believe this is the main thing that makes processed food unhealthy, and, indeed, is the main driver of the epidemic of the so-called "diseases of civilization" (obesity, diabetes, cancer, etc) that most of the world is experiencing. This series of blog posts does an excellent job of summarizing the evidence: https://www.jeffnobbs.com/posts/what-causes-chronic-disease https://www.jeffnobbs.com/posts/what-causes-chronic-disease

bumby 5y ago
What are the main causal hypotheses regarding why seed oils lead to obesity? I didn’t see much in the article regarding the mechanism that links the two. I know Catherine Shanahan has written about this link and talks about how easily seed oils cause inflammation through free radicals. But how do we get from inflammation to obesity?
- resoluteteeth 5y ago
  A lot of research on these topics assumes the existence of metabolic syndrome / syndrome x, which is a hypothetical syndrome that is the supposed to be the common cause of obesity, diabetes, etc. Metabolic syndrome used to be very mainstream but I'm not sure it's taken quite as seriously in the scientific community recently. However, if you do assume the existence of metabolic syndrome, you can pretty much justify a link between anything that could potentially be its cause and obesity. For example, if seed oils cause some sort of metabolic dysfunction resulting in metabolic syndrome, then that would then result in obesity. Obviously, if you assume that obesity is just caused by excess consumption of calories, and that obesity is then the cause of diabetes, and that there is no separate metabolic syndrome it becomes harder to justify this kind of theory. That link doesn't explicitly use the terms "metabolic syndrome" or "syndrome x" but it seems like it is probably implicitly assuming its existence.
  - deleted 5y ago
    [deleted]
- dilap 5y ago
  The million dollar question! No one really knows. There are some theories. One thing is linoleic acid converts into endocannabinoids, which stimulate appetite. Too much n6, too much appetite, obesity, is the theory. If you google around on e.g. pubmeb you can find various papers proposing this. But there's probably more to it than that; there are pig and mouse studies where the animals are fed isocaloric diets, but the animals eating high LA get fat. So that strongly suggests that it's not just a appetite-based overeating thing. The blog hyperlipid proposed a theory involving ROS signaling at a cellular level; my knowledge of biology and metabolism is sadly minimal, but at a very high level I think the theory is something like, "having too much linoleic acid in the diet signals cells to remain unnaturally insulin-sensitive and accumulate fat". See also: the blog Fire in a Bottle, which tries to summarize the hyperlipid theory at a less low-level, technical level. https://pubmed.ncbi.nlm.nih.gov/27350414/ https://pubmed.ncbi.nlm.nih.gov/27350414/ https://high-fat-nutrition.blogspot.com/2013/08/protons-so-far-some-sort-of-summary.html https://high-fat-nutrition.blogspot.com/2013/08/protons-so-f... https://fireinabottle.net/the-ros-theory-of-obesity/ https://fireinabottle.net/the-ros-theory-of-obesity/

by dilap 5y ago

bumby 5y ago

What are the main causal hypotheses regarding why seed oils lead to obesity? I didn’t see much in the article regarding the mechanism that links the two. I know Catherine Shanahan has written about this link and talks about how easily seed oils cause inflammation through free radicals. But how do we get from inflammation to obesity?

resoluteteeth 5y ago
A lot of research on these topics assumes the existence of metabolic syndrome / syndrome x, which is a hypothetical syndrome that is the supposed to be the common cause of obesity, diabetes, etc. Metabolic syndrome used to be very mainstream but I'm not sure it's taken quite as seriously in the scientific community recently. However, if you do assume the existence of metabolic syndrome, you can pretty much justify a link between anything that could potentially be its cause and obesity. For example, if seed oils cause some sort of metabolic dysfunction resulting in metabolic syndrome, then that would then result in obesity. Obviously, if you assume that obesity is just caused by excess consumption of calories, and that obesity is then the cause of diabetes, and that there is no separate metabolic syndrome it becomes harder to justify this kind of theory. That link doesn't explicitly use the terms "metabolic syndrome" or "syndrome x" but it seems like it is probably implicitly assuming its existence.
- deleted 5y ago
  [deleted]
dilap 5y ago
The million dollar question! No one really knows. There are some theories. One thing is linoleic acid converts into endocannabinoids, which stimulate appetite. Too much n6, too much appetite, obesity, is the theory. If you google around on e.g. pubmeb you can find various papers proposing this. But there's probably more to it than that; there are pig and mouse studies where the animals are fed isocaloric diets, but the animals eating high LA get fat. So that strongly suggests that it's not just a appetite-based overeating thing. The blog hyperlipid proposed a theory involving ROS signaling at a cellular level; my knowledge of biology and metabolism is sadly minimal, but at a very high level I think the theory is something like, "having too much linoleic acid in the diet signals cells to remain unnaturally insulin-sensitive and accumulate fat". See also: the blog Fire in a Bottle, which tries to summarize the hyperlipid theory at a less low-level, technical level. https://pubmed.ncbi.nlm.nih.gov/27350414/ https://pubmed.ncbi.nlm.nih.gov/27350414/ https://high-fat-nutrition.blogspot.com/2013/08/protons-so-far-some-sort-of-summary.html https://high-fat-nutrition.blogspot.com/2013/08/protons-so-f... https://fireinabottle.net/the-ros-theory-of-obesity/ https://fireinabottle.net/the-ros-theory-of-obesity/