Monday, September 22, 2008

Fat makes you healthier!

Ok, my title may be going a bit too far, but new research coming out of Harvard University has found a fat, an omega-7 fatty acid called C16:1n7-palmitoleate, which does just that. The lipid is the first of its kind found to act as a hormone, signaling muscles cells to react better to insulin and reducing levels of inflammatory chemicals produced by the body.

The breakthrough came after previous studies led by Gökhan Hotamisligil, a geneticist at Harvard. His team had found that blocking two proteins which normally bind fatty acids actually led to super-mice, who were "almost indestructible. No heart disease, fatty liver disease, diabetes, no asthma, nothing.” These mice were healthy even on a high-fat diet (see the super-mouse on the left, normal mouse on the right, fed a high-fat diet). They had expected that blocking a lipid-binding protein would lower the mice's health, since it would lead to higher fat concentrations in the blood which are assumed to have ill-effects. Such strange results led the researchers to look a little deeper into why the lack of these proteins had such a positive effect when normally higher fat means lower health.

The answer surprised the scientists. It turns out fat isn't just fat - there are many different kinds, some healthy, some unhealthy. When the scientists examined the composition of the fats in the super-mice, they found that palmitoleate, normally rare, was the third most common. The fat, in addition to booting the response to insulin in muscle cells, prevents liver cells from accumulating harmful fats, and reduces the amount of inflammation-promoting chemicals which are linked to heart disease, diabetes, and other illnesses. The fat cells in these mice weren't able to store dietary fat and resorted instead to making their own fats, namingly palmitoleate. Thus the lack of two proteins had an unbelievable health benefit.

The good news - some fats are good for you. The bad news - when the mice were fed a high-fat diet, their liver cells cut palmitoleate production in half. So a diet of fast food and cheesecake isn't going to make you healthier. However, if new research can find the best way to stimulate your cells to make this miracle lipid, it could lead to new advances in nutrition and dieting. So let's hear it for fats! (some, anyway). The research is published online in the September 19th edition of Cell.