Polyunsaturated fats: why are they harmful? Part I

Some people in nutritional science are aware that the polyunsaturated fats such as those found in industrial vegetable oils can be harmful. But few people that I’ve read seem to illustrate why PUFA are harmful in a way that gives a logical understanding. When someone says something is harmful they are merely stating something. It does not mean they actually understand the “why”. A person might read a study and the study might be correct and that person may regurgitate what was in the study. Though the person may be informed they lack the visual pictures painted in the mind that helps to form a basis from which other conclusions can be drawn. In other words, they have no real understanding. That phenomenon is rampant in nutritional science. From a practical standpoint that approach may work, but for a person who is in a complicated situation or trying to understand more than that, the approach is limited, and taking shots in the dark could have negative consequences.

In order to understand the world around us, we cannot just memorize facts and connect dots. It leads to superficial understanding.

Many people have said that polyunsaturated fats are harmful and have provided evidence for why by putting together pieces of their effects in different contexts. But that does nothing in the end to help us to predict upstream and downstream effects, in that approach we are without prediction power for making rational choices.

In your body you have different lipid-like hormones and nutrients. A lot of these hormones and nutrients are unsaturated. In other words, they resemble the polyunsaturated fatty acids. In a body that doesn’t have bottles of corn oil floating around, these unsaturated hormones and nutrients bind to the cells as they should, like putting a key into a keyhole. Though that is a rather mechanical way of thinking about it, the analogy is useful. When you consume polyunsaturated fats they in effect bind to the same places your hormones would normally bind. As long as the body remains fairly unstressed this poses minimal problems in the short term.

Under stress, however, the body releases the protective hormones. If the body is saturated with the polyunsaturated fats, the unsaturated hormones can no longer bind. Over time, the body can no longer respond to stress efficiently because the protective hormones can no longer function, in effect, the polyunsaturated fats are mimicking the binding of unsaturated hormones blocking the protective hormones from functioning.

Over time, as we age, we gradually lose the ability to respond to stress because of this process. In other words, resistance to stress is the ability to respond to stress efficiently. As we lose the efficiency to respond to stress, we age because we are unable to repair the damage caused by stress. In other words, aging is a feature of the body not being able to respond to stress efficiently and completely. Stasis must shift to maintain balance. It is the shifting process that can be problematic.

In the cell there is an organelle called the peroxisome. The peroxisomes break down lipid like substances or xenobiotic compounds. In other words, they protect the cell from foreign compounds. That seems to be one of their primary functions.

What is interesting here is that the mitochondria work in a similar parallel when they metabolize oxygen.

I had known from prior research that the polyunsaturated fats cause problems with cellular respiration by reducing the efficiency of the mitochondria, thus overall efficiency of the cell, in a sense turning the mitochondria into “mush”. Different fuel substrates have differing efficiency, so I needed something more, something that pointed to a problem with the nature of polyunsaturated fats themselves.

When a cell is exposed to PUFA the peroxisomes proliferate or increase in number rapidly. Peroxisomes are especially sensitive to the unsaturated fatty acids. In the laboratory, fish oil is commonly used in their study. Interestingly, the saturated fats do not cause proliferation in most cases. It is also interesting that cholesterol lowering drugs also cause peroxisome proliferation. Remember: peroxisomes proliferate when exposed to harmful substances.

So the cells can, to some extent, protect themselves from PUFA by breaking them down. Given that, why can’t we consume PUFA with a clear conscious? And why do some people seem to be able to eat more than others?

Part 2 shortly.

5 Comments Polyunsaturated fats: why are they harmful? Part I

  1. Tanya

    This is an interesting post Edward. This is where I struggle with Peat. I do not have the background knowledge on the human body and nutrition (and most other things) to make truly informed decisions about my health. I sort of just need to ‘trust’ Peat in a way. I think many people are like this. I feel this is ok for my own decisions about what I eat, how I live etc. But I get caught out when I try to explain myself to other people, as really, I’m just parroting someone else. I try not to say to much about why I eat the way I do.

    Question Edward: what are your thoughts on Peat’s statement that it would take about 4 years of PUFA restriction to get an acceptable ratio of saturated to unsaturated fats in the body? Is that even possible? Would this then allow the peroxisomes that you mention in your post to do their thing without being inundated by an ungodly amount of unsaturated fats? And in your opinion, are saturated fats therefore the preferred fat fuel source for the body? Thanks.

  2. mitchell

    Gauging by this post I’d really enjoy part two. I hope you will get to it at some point. Great to find your blog again.

Leave a Reply

Your email address will not be published. Required fields are marked *