All fats aren’t equal

A motor oil company pointed it out in the 1980s, “oils ain’t oils”, and it is something that biologists have known for some time. While the advertisers were trying to make a point to motorists with their marketing, for biologists it is simply a fact that all oils or fats are not the same in the body. Some fats behave very differently to others and researchers now believe they know a big part of the reason why.

It is already known that some fats, mostly the unsaturated ones that are typically found in plant oils, have antimicrobial properties. When exposed to unsaturated fats bacteria tend to die, whereas by contrast saturated fats do not have those properties and in fact appear to provide a carbon source that feeds bacteria.

These researchers analysed years worth of studies around this topic and found that there is a strong relationship between fats that have antimicrobial properties also having an anti-inflammatory effect. Similarly, the fats that did not have antimicrobial properties tended to be inflammatory.

The explanation for this, according to the researchers, is probably that the saturated fat sets off a kind of early warning system in your body. They believe that over the millennia human bodies have evolved to recognise when fats that encourage bacterial growth are present. To defend against this potential overgrowth an immune response is launched and that immune response turns into prolonged low-level inflammation which in turn causes chronic disease such as diabetes and heart disease.

At the moment this is largely theoretical. It does however seem that saturated fat encourages the growth of harmful bacteria in the digestive tract. The leap from this to causing long term inflammatory disease remains unproven in the human body. As far as the different effect from one fat to another though, it certainly gives us something to chew on…or not.