Inflammation and Obesity- Inflamed in The Brain?
There’s some really interesting research that recently came out not only on inflammation and obesity, but inflammation and diabetes as well. Really, the two are closely related because of the influence of the hormone insulin, so this shouldn’t be so surprising, especially if you’ve read my post on insulin and weight gain.
To sum up, consuming a diet high in fat seems to create a problem with inflammation in the hypothalamus, a region of the brain that links the nervous system to the endocrine (hormonal) system through a little nubbin at the base of the brain called the pituatary gland (also called the “master gland”). This inflammation then impairs the effects of two hormones, insulin and leptin, on signalling the body about fat storage.
Okay, let’s break down what that all means.
Inflammation and Obesity
First off, there’s a chemical on/off switch for inflammation in our body called NF-kB (NF- “kappa” B). When NF-kB is activated, it’s like in those submarine movies where that klaxen horn begins blaring Ah- WOOO-GA! Ah-WOOO-GA! and a voice shouts over the loudspeaker “Dive! Dive!”.
Okay, maybe that’s just my hyperactive imagination. But seriously, when NF-kB is activated, it tells the body that inflammation is necessary in that area. We’ve discussed NF-kB in detail before in this post on inflammation and antioxidants. The key thing to realize for this discussion is, a high-fat diet seems to activate NF-kB in the hypothalamus, leading to inflammation in that area.
This leads to resistance to the hormones insulin and leptin. Insulin we’ve discussed many times before- it’s the hormone involved with controlling blood sugar. It’s also the hormone of interest in diabetes and the pre-diabetic state called “metabolic syndrome”, “syndrome x”, or just plain “insulin resistance”.
Resistance to insulin causes all kinds of health problems, but in this case, we’re mostly interested in the fact that abnormal expression of insulin causes weight gain. If you’ve heard of low-carb diets, the whole mechanism behind their action is to control the levels of insulin in your body so that you don’t get fat. Once again… abnormal action of insulin leads to fat gain. Since an inflamed hypothalamus leads to abnormal action (i.e., resistance) of insulin, it therefore also leads to fat gain.
Inflammation, Leptin, and Hunger
What about that other hormone, leptin? What the heck IS that other hormone, leptin?
Leptin is a hormone that controls the sensation of hunger and/or saiety (the feeling of being full). Again, when inflammation kicks in throughout the hypothalamus, you end up with an abnormal expression of this hormone… in other words, an inflamed brain is always telling you you’re not full yet, no matter how full you actually are.
So not only does an inflamed brain disable the hormonal mechanisms that help burn off fat and sugar (that’s insulin), it also disables the hormonal mechanism that tells you to stop stuffing your pie-hole in the first place! Is it any wonder how this could lead to weight gain?
There’s been links between inflammation and obesity before, but this is a much stronger link because the hypothalamus, as I mentioned earlier, pretty much runs the show when it comes to your hormones. That means that inflammation there is going to have a far greater effect than inflammation in the peripheral tissues.
Fat Quality and Inflammation
I talk a lot about the importance of healthy fats in the diet, and how the balance of Omega-3 (anti-inflammatory) fats and Omega-6 (pro-inflammatory) fats is so vital to proper function in the body. It may very well be that it is not a problem of overall quantity of fats, but an overdose of those inflammatory Omega-6 fats that is leading to this inflammation problem in the hypothalamus.
In fact, one of the articles on the subject shows that saturated fats are far more likely to induce this inflammed state in the hypothalamus, and therefore leading to the disruption in insulin and leptin that contributes to weight gain. Monounsaturated fats did not seem to have the undesirable effects.
My advice is, this is even more evidence to avoid processed foods (which are high in pro-inflammatory Omega-6s) and stick to a whole foods diet (also called a “primal” or “paleo” diet). Additionally, supplementing with Omega-3 fats like fish oils can help reduce inflammation, and antioxidants can help, as well. Read that article I linked to above for evidence on how antioxidants seem to shut off that NF-kB inflammation switch.
Since inflammation and obesity are linked, you want to avoid that situation as much as possible. A healthy whole foods diet is the best defense. After all, who wants an inflamed brain?
Stay healthy!