The CLA or conjugated linoleic acid is produced from a fatty acid of the Omega group 6. In the traditional diet it is predominantly found in cow’s milk and beef or mutton. It is also present in good quantities in cheeses but, as for milk, the CLA (or ALC in French) rate is quite variable.
Moreover, the composition is different from that which can be found in supplements produced from various oils.
Indeed, while the feed supplies CLA composed of trans-10, cis-12 and cis-9, trans-11 at 70 and 30%, this proportion may be quite different depending on the supplements used. It should be noted that most CLA studies have been done on proportions of the order of 50/50%.
Effectiveness of CLA
The CLA was first studied for its anti-cancer properties before being used to treat animals and increase their muscle mass while decreasing their fat mass. Treatment appears to have worked effectively on animals but the functioning of CLA in the body is not yet known and it is suspected that the mechanisms may have different effects from one species to another.
This is why, in human studies, some subjects appear to have benefited from a slight decrease in fat and muscle growth, while others have not benefited from any particular effect. For those who have responded to the product, the results indicate a reduction in fat mass of about 1 kg over 10 weeks of treatment.
In short, not all studies are conclusive and it is possible that the effects of CLA vary greatly from one person to another depending on its genetics and origins. It should be noted that studies that have been shown to be effective have been carried out in Nordic countries such as Sweden and Norway and that when fat loss occurs, subjects appear to have gained an equivalent weight of muscle.
Where to find the CLA and what dosage to use?
As stated above, it is found in products derived from ruminants such as meat or milk. But since it is difficult to know how much they contain, it is impossible to control the ingested doses.
Moreover, it seems that the human body can not effectively manufacture CLA from linoleic acid.
All these parameters combine to give the body only a maximum of 1g per day. However, it would appear that the minimum dose to take advantage of its benefits would be 3g per day. It is therefore advisable to go through the use of standardized supplements to obtain the right dose and use a CLA composition close to that of the studies.
Therefore, taking CLA at the recommended dosage will not necessarily cause a change in the fat/muscle ratio of an individual. But studies have also looked at other possible effects of CLA and it is clear that the results are equally divergent.
This is the case, for example, with regard to the metabolism of blood glucose which CLA could normalize in animals but which does not appear to have changed in human studies.
Similarly, research on the impact of CLA on cholesterol is contradictory, indicating, for some, an increase in good cholesterol, for others, a decrease in global cholesterol and still others demonstrate zero effectiveness.
Finally, animal studies converge towards a positive effect of CLA on the immune system and allergies. But again, the studies on human beings diverge and it is impossible to know what it really is for now.
Some studies are more worrying when it comes to testing the effect of CLA on diabetes. It appears that trans-10, cis-12 conjugated linoleic acid has a negative impact on diabetes. This is in any case what are reported in clinical trials on people suffering from obesity. Although this effect does not necessarily appear to be timely for all individuals, this is a fact to be taken into account when starting a CLA cure, particularly in the case of a person suffering from diabetes or obesity.
Other side effects are also noted, such as gastrointestinal disorders and fatigue. A recent worrying study, involving a commercial supplement, also pointed to a deterioration in the flexibility of the arteries.
Although CLA may have a beneficial effect in some people, its potential is yet to be proven and its mechanisms need to be demonstrated. In addition, complementation should be done with a knowledge of the potential negative effects and remaining vigilant. The effective dose of 3g should be taken several weeks before any efficacy can be seen, if there is one, which is not mandatory.
The use of this type of supplement is obviously not recommended for pregnant women, children and people with obesity, diabetes or liver problems.