Alexa Fleckenstein M.D.

My experiment is going on. Of course, I have no idea if it is really new brown fat that turns me into an oven every time after my daily cold laps in the pool. For all I know, I could have a not-yet-recognized infection or any other disease that makes me burn up. Only thing I know is that I feel terrific – for the moment. But for the sake of an interesting exploration, let’s stick with my brown fat hypothesis. This is what I have learned about about brown fat so far: 1. It used to be thought that only babies (protecting them from hypothermia) or bears (keeping a reasonable core temperature during hibernation) have brown fat. It turns out that traces of brown fat are still around in adult people. – A little aside: Other ways to increase body temperature are increasing surrounding temperature, moving about, shivering, and eating certain “warming” foods like cinnamon, ginger, onions, garlic, rutabaga, coriander, cloves – interestingly foods often used in the winter kitchen. But there is no hint that those foods increase brown fat. Or a shred of a proof that a so-called "Brown Fat Diet" will increase that precious tissue in your body. 2. Brown fat can help weight loss by increasing metabolism speed. 3. Brown fat also can decrease elevated insulin-resistance (also called pre-diabetes) and a diabetic situation. 4. Brown fat can be induced to increase by cold exposure – be it by swimming in cold water, immersing in a tub filled with ice water, or dancing in a walk-in food refrigerator (don’t you wish you had one of those at home??). 5. Needless to say, there are already pharmaceutical firms are already working on drugs that might trigger growth of brown fat, without going through the ado of cold exposure. The easy way out, I call it. And definitely not an interesting way, if you ask me. I like to think about cold-induced brown fat as one of the benefits of moderate stress. We all know that stress is bad for you, don’t we? Not necessarily though. Moderate stress might be what makes the body function in the way Nature intended it. With heated dwellings with forgo the winter cold stress – and get sick for it, lacking brown fat. With air-conditioning in the summer, we miss out on the sweating which give our body a good cleanse of all the toxins – and get sick for it. Occasional hunger stress (fasting!) is another beneficial stress mechanism. Not only do we get healthier on occasional fasting, and live longer with less belly ballast, it also seems we get to be happier with fewer pounds – and less depressed. One estimate is that there are about three million residential swimming pools in California (I am not even mentioning the pools in Florida and all across southern U.S.A.). If these pools are anything like our pool here in La Jolla, all those turquoise eyes should be gazing at the sky, basically unused. All, of course, using up precious water resources. How about using them? If you are in decent health (ask your physician), you start by doing a single lap across your pool. Tomorrow two, and every day one more until you reach twenty-one laps. The brown fat will appear very fast – and will help you lose weight. Putting on brown fat, however, might mean walking a fine line: You want to increase your metabolism by cold exposure. But you don’t want to get where most winter swimmers end up: with more fat on their bodies. Fat (of any kind) protects against cold, and makes you better able to withstand long swims in icy water. Don’t go there!