In an earlier post, we explored the role that visceral fat may play in immunity. And in a way, I was defending it because we tend to talk about it as if it’s just a one-dimensional bad guy when it comes to cardiometabolic health. Certainly, if you have more visceral fat, you do have a much greater risk of insulin resistance and related problems. The location of the visceral fat is unique in that it is a first line of defense against things that may be coming from the intestines, such as happens with leaky gut syndromes. Leaky gut has become a very popular thing to be worried about. And to a degree, that’s justified. It is a problem. I thought I would just elaborate on that a little bit and then maybe even touch on something you could do to help.
Please keep in mind that I’m not a “gut” scientist, though I’m certainly familiar with gut physiology. I’m a “fat” scientist, so I’m going to look at leaky gut through the lens of fat.
Briefly, a gut works in part by creating tight junctions . That’s actually what they’re called. It’s when epithelial cells, or the cells that line our intestines, are intimately linked together, making sure that essentially nothing is slipping through. Whatever is getting into the body should be going into the epithelial cells that line the intestines and then moving into the blood. So things we want to absorb normally go through the cell and these tight junctions help make sure that things aren’t slipping in between the cells.
Interestingly, the single most common fat that we eat now in the western diet is an omega-6 fat called linoleic acid mostly from things like soybean oil, canola oil, cottonseed oil, or similar. These are sometimes called vegetable oils, which is a terrible misnomer. It’s not from vegetables at all. While the polyunsaturated fat linoleic acid reduces the integrity of these tight junctions, saturated fats actually improve them . Even beyond the tight junctions, saturated fats actually help the intestines heal, something many people would benefit from . This matters! We’ve been told to avoid saturated fats in favor of polyunsaturated fats, and we’ve obeyed—as mentioned above, we now eat more fat as polyunsaturated fats than saturated . Our blind dietary obedience may be directly contributing to our intestinal problems.
So, visceral fat is that first line of defense against dirty invaders from the gut, and thank heavens for it. Let’s help the visceral fat by helping the gut be less leaky. To a large degree, based on the data that I’m sharing with you, it might be partly a result of the type of fat we’re eating. This is just more evidence that we are built to eat fats that come naturally, and these are animal fats and fruit fats (coconuts, avocados, olives). In general, those are going to provide saturated and monounsaturated fats, with relatively very little omega-6 polyunsaturated fats. And it’s the polyunsaturated fats, especially from refined seed oils, like soybean oil and similar, that appear to do the most damage when it comes to gut permeability and gut healing.
1 Lee, S. H. (2015) Intestinal permeability regulation by tight junction: implication on inflammatory bowel diseases. Intest Res. 13, 11-18
2 Abulizi, N., Quin, C., Brown, K., Chan, Y. K., Gill, S. K. and Gibson, D. L. (2019) Gut Mucosal Proteins and Bacteriome Are Shaped by the Saturation Index of Dietary Lipids. Nutrients. 11
3 Blasbalg, T. L., Hibbeln, J. R., Ramsden, C. E., Majchrzak, S. F. and Rawlings, R. R. (2011) Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century. The American journal of clinical nutrition. 93, 950-962