Lipid Nutrition is today announcing the findings of a new human trial using CLA, that reinforces the fatty acid's fat mass reduction claim and shed light on the main locations of the fat reduction on the human body. The results, presented by Dr Sandra Einerhand, director nutrition and toxicology Europe, at Vitafoods in Geneva, reinforce the ingredient's promotional claim to be a body shaper - especially for the upper leg and abdomen areas.
CLA (conjugated linolenic acid) is a fatty acid naturally present in ruminant meat and dairy products. Due to changes in the Western diet, average intake of CLA has fallen; if the fat is removed from a dairy product to make a low fat version that will be acceptable to consumers, CLA is removed along with it.
Moreover Dr Einerhand explained to NutraIngredients.com that CLA is metabolised by bacteria in the stomachs of cows from the grass they eat, but modern farming methods may mean they are not left outside to graze for as long as they were in days gone by.
This has led nutraceutical companies to research and promote CLA for use in dietary supplement and food products, largely based on its two-fold effect on humans: the reduction of fat mass and the induction of lean body mass.
Lipid Nutrition's CLA ingredient, called Clarinol, is derived from safflowers. It has two CLA isomers - known as trans-10 cys-12 and cys-15 trans-11, are respectively responsible for the effects.
The mechanism of action has been well studied: if fat consumed is not used for energy, the triglycerides are taken up by fat cells - a mechanism for which the enzyme lipoprotein lipase is responsible.
CLA inhibits this enzyme, and instead the triglycerides are diverted to the muscle cells to be burnt. Here the CLA induces the activity of another enzyme, carnitine palmitoyl transferase, which is responsible for oxidation and the burning of fat.
The new placebo-controlled, randomised, double-blind study was conducted at an independent research institute and involved 180 obese or overweight adults with a body mass index between 28 and 32.
Over a six month period they received either 3.4g of CLA each day, or a placebo (olive oil).
Dr Einerhand said that the results were already evident eight to 12 weeks into the study, but at the end of the six months the effect on fat mass was seen to be around 2kg compared to the placebo - equivalent to eight packs of butter.
Lean body mass was seen to increase by an average of 0.4kg in the CLA group, over the placebo group.
But the area in which the study really shed light is the location of fat mass reduction - seen to be focused on the abdomen and the legs. This gives credence to the ingredient's promotional claims to be a body shaper.
The method used to measure the shape-changing was Dural energy x-ray absorptiometry (DEXA) - a process that involves scanning the body to highlight changes in fat and body mass.
In addition, the study provided more evidence for the safety of CLA over a long period: it was well-tolerated by all the participants over the six-month period.
The researchers also measured certain safety parameters, such as inflammatory and diabetagenic markers.
In a sub group of 41 participants, the researchers measured insulin sensitivity - an important consideration since overweight or obese people may run a higher risk of metabolic syndrome or full-blown type-II diabetes. To do this, they used an englycemic clamp - a time consuming procedure that is nonetheless considered the gold standard.
"We needed to be sure that it does not affect insulin sensitivity," said Dr Einerhand.
Not only were the researchers satisfied that insulin sensitivity was not impaired, but the trend (although not significant) was towards improvement.
Dr Einerhand said it is expected the study will be published in a peer-reviewed journal in due course.