A link between conjugated linoleic acid and weight loss (CLA) has been established in animals but the evidence for weight loss in humans is sparse.
In one study, mice fed a diet consisting of a fixed number of calories that was supplemented with CLA put on 60% less body fat than the mice in the control group.
The researchers concluded that this was probably due to a combination of reduced fat deposition, increased release of fat from cells and higher levels of fat breakdown.
This is consistent with an increasing body of evidence relating to the effect of CLA on body composition in animals.
But is there evidence that CLA works to reduce body fat in humans?
Conjugated Linoleic Acid and Weight Loss in Humans…
In other words, the jury is still out.Recent human obesity studies would suggest a qualified yes, but, maybe…
A study in 2004 that was reported in the American Journal of Clinical Nutrition is often quoted as evidence for its effectiveness.
Researchers in Norway gave 180 healthy men and women with a BMI of 25-30 (overweight, not clinically obese) one of two types of CLA or a placebo.
They were also put on a calorie controlled diet. At the end of the 12 months trial, the participants given the CLA showed reductions in body weight and BMI. The placebo group didn’t.
But don’t get too excited, the average weight loss over the year-long trial was a whopping…wait for it, 4 lbs! With a 0.5 reduction in BMI as well.
This evidence has been seized upon by supplement manufacturers. The result is that all sorts of outlandish claims are made about the link between conjugated linoleic acid and weight loss and the miraculous results that people who take it can expect.
Without much more research, it’s unlikely that nutritionists and the scientific and medical communities would agree!
Whilst there were few serious side effects reported by the test group in the study we’ve just quoted, further research is needed to test the safety and effectiveness of CLA.
So What is CLA…?
CLA is a fatty acid that has been shown to have a preventitive effect on heart disease and cancer in animals. It’s also been shown to lower blood cholesterol levels.
It’s found in cows’ milk and cheese, for instance.
Synthetic CLA can be made in the laboratory and is a mixture of two different chemical forms of CLA.
One form, 9-11, is thought to be the anti-cancer variety. The other, 10-12, is thought to be responsible for reducing body fat.
Whilst the effects of CLA on cancer and heart disease are perhaps more advanced, the link between conjugated linoleic acid and weight loss are less robust.
Nevertheless, CLA is a very popular supplement, often marketed as a fat burner. It’s readily available from a large number of supplement companies. Just try doing a search on the internet and be ready to drown in the deluge of ads!
The Bottom Line…
We would have a few concerns over the safety of taking large doses of CLA in the long term. However, no significant side effects have yet been reported and as CLA appears for the time being to be a relatively safe supplement, it may be worth a try.
However, it’s no miracle weight loss pill and do not get drawn into the “lose weight without changing your diet and doing any exercise” hype.
Yes, there is some very limited evidence of a benefical link between conjugated linoleic acid and weight loss, but the effect is small.
As such, CLA may be of some limited benefit as a supplement to your weight loss program, but not as a substitute for one.