Fat has a bad name in all sorts of circles. Most of us seek to minimize fat on our bodies, and we attempt to reduce how much of it we eat in order to do so. Fat really isn't very pretty to look at, lacking the glorious symmetry of say, muscle. But now comes a study suggesting that we take at least one specific type of fat out of the bucket in which we've lumped all fats together as devoutly to be avoided and extol its virtues. It goes by the tongue-challenging name of trans-palmitoleic acid, and in this issue of Annals of Internal Medicine we learn that consumption of this fat may reduce the risk of developing diabetes.
Trans-palmitoleic acid is found in whole fat dairy products. Yes, you read that right, whole fat. In this cohort of almost 4000 adults in the Cardiovascular Health Study, those who presumably consumed more whole fat dairy products had higher circulating levels of trans-palmitoleate in their blood. Higher levels of this factor were associated with slightly lower body fat, higher HDL cholesterol (the good type) and a lower risk of developing type 2 diabetes. The inflammatory marker C-reactive protein was also lower in this group.
Well. Does this mean that we should wholesale make the switch back to consumption of whole-fat milk, cheese, yogurt and the like? In some ways the discussion reminds me of evidence that margarines containing manmade fats (trans fats, by the way) were much worse with regard to atherosclerosis potential than butter, which blew onto the scene several years ago. Rick opines in this week's podcast that no, we all can't make that switch quite yet, but the study points to the need for more definitive ones to nail down the potential benefit of this fat. He does give Santa permission, however, to consume whole milk along with those multitudinous Christmas Eve cookies.
Rick and I both agree, however, that the study once again demonstrates that things are more complicated than they look. Used to be that fat was fat and that was that, and we shouldn't eat it in order to avoid a host of cosmetic and health related faux pas. This closer look at one type of dietary fat lets us know that once again, we need more evidence. Good job security for researchers out there.
A word here for any non-scientists in the bunch about 'trans' fats and how to tell the villains from the good guys. Trans simply refers to which side of a molecule another chemical group is attached to, and it comes from Latin. Turns out that molecules can be thought of as having both right and left sides, with the Latin 'cis' meaning the additional chemical group is found on the same side, and 'trans' meaning on the opposite side. In the case of fats described here, trans palmitoleic acid is a naturally occurring fat while those trans fats found in madmade margarines are not. They share the characteristic of having chemical groups on their opposite sides but there the similarity ends. In my mind this finding underpins my own freely admitted bias that with regard to foods: if you could have found it when we all lived in caves then it's probably okay to eat it, but what really needs to be avoided is excessive refinement.
Other topics this week include two more from Annals: Echinacea for the common cold and preventing falls in older adults, and one from JAMA: the long term benefit of exercise in preventing weight gain as we age. Until next week, y'all live well.
Finally, a Good Fat!,3 Comments