Fat burner or money waster?
You've probably heard of omega-3 and omega-6 fatty acids. Eating too much omega-6 containing foods can lead to cancer, cardiovascular disease and excessive inflammation. And the consumption of omega-3 fatty acids is important because it can keep these inflammations under control. But there is an exception to the omega-6 fatty acids and that is gamma-linolenic acid, or GLA for short.
What is GLA?
GLA is considered an essential fatty acid. Whenever a nutrient is labeled as "essential" it means that you have to eat it to get it. Your body can't make this nutrient on its own like it can with many other things. The two essential fatty acids you need to consume in your diet are omega-3 and omega-6 fatty acids. However, you shouldn't overdo it and eat tons of omega-6 fatty acids. That's what most Americans do and it's the cause of some problems. GLA is an omega-6 fatty acid, but a special one. If you're familiar with omega-3 fatty acids, then you know their ability to regulate inflammation. And because of this fact, you may also take fish oil capsules. Well, what makes GLA so special is the fact that GLA is an omega-6 fatty acid that does not cause inflammation. In fact, GLA reduces inflammation.
Is GLA a fat burner?
There are many claims regarding the effects of GLA, including its ability to burn fat. Some even go so far as to say that GLA is the dietary fat that burns fat. Why? Because they believe that GLA activates what is known as brown adipose tissue. You need to know that the body has two different types of adipose tissue: brown adipose tissue and white adipose tissue. Brown adipose tissue is considered metabolically active tissue, which means that it contributes to the body's thermoregulation and therefore also to energy consumption. Sounds pretty cool, doesn't it? But wait, before you go searching on Google for all the things that could increase brown adipose tissue activity, you should be aware that you probably won't get that far.
Hibernating mammals have more brown adipose tissue than humans because this adipose tissue is needed for thermoregulation during the long winter nap. Of course, humans also have brown adipose tissue, but in humans this is mainly a phenomenon during infancy. It serves as a protective mechanism to keep babies warm, as they do not have the necessary muscles to shiver and thus produce heat. As we get older, the amount of brown adipose tissue decreases and the amount that remains varies from person to person. So you will still have brown adipose tissue, but not as much as you used to and you may not be able to increase this amount. A study published in the Journal of Obesity showed that brown adipose tissue could be identified in adult humans who were exposed to cold for two hours by placing their legs on a block of ice. After the subjects underwent this process, activation of brown adipose tissue was observed in the supraclavicular and paraspinal regions.
However, the weak point of the study is that it only included thirteen subjects and only six of them showed activation of brown adipose tissue. Unless you lie down on a block of ice for two hours and spend a lot of money on the relevant evaluations, you won't know how much brown adipose tissue you have or how active it is in your body. And there is probably a 50% chance that you won't have much brown adipose tissue in adulthood.
But what if I am one of the 50% who have activatable brown adipose tissue?
Let's assume that you are one of the people who have some brown adipose tissue. Then you would be the type of person who could burn a ton of fat by using GLA, right? In a way, yes.
The study that most people are referring to in this context comes from Japan and was published in the Journal of Comparative Biochemistry and Physiology. This study was able to show that brown adipose tissue was activated in a group that was given GLA and that this group of subjects gained less body fat than the control group. Is this proof that GLA works? Not necessarily, because there are a few things you should know. First of all, this study was conducted with rats as study subjects. Animal studies are used as a first step to find out if there is reason to believe that a nutrient has therapeutic effects in humans. If this is the case, a study is conducted with humans as subjects. And sometimes results can be observed in rats that cannot later be observed in humans. So this is simply a transfer of data from rats to humans. But there are also some studies that show that GLA can contribute to fat loss in humans. The fact is, however, that there are a few problems with these studies. The biggest problem is the type of subjects that were used.
For example, a study published in the Journal of Nutrition showed that GLA can reduce weight gain in people who were previously very overweight. If you are a formerly obese person, then this could also apply to you. However, if you are a regular fit person who has never been obese, this may not necessarily apply to you. GLA has been shown to help prevent weight gain, but that doesn't necessarily mean that it can help an already quite slim person reduce their body fat percentage from twelve to six percent. This requires good old hard work and a smart diet.
Conclusion: As long as there are no further studies carried out on humans, it is not clear to what extent GLA can contribute to fat loss in people who exercise. There is no harm in taking GLA, as it is safe and has other health benefits, but no one can say in advance to what extent it can help you lose fat.
Better proven benefits of GLA
Let's dig a little deeper into the science. Your body's ultimate goal is to get dihomo gamma-linolenic acid (DGLA), which is a derivative of GLA. DGLA can reduce inflammation in two ways. Firstly, it is converted into PGE1, which has anti-inflammatory effects. Secondly, it can be converted to 15-HETrE via the 15-lipoxygenase pathway, which has the ability to inhibit the formation of 5-lipoxygenase, which can lead to the formation of pro-inflammatory metabolites.
If you look at the diagram above, you can see that linoleic acid can be converted to GLA and then to DGLA. At this point, DGLA can have a direct anti-inflammatory effect by producing PGE1 or an indirect effect via the production of 15-HEtrE. You might think that consuming more linoleic acid (an omega-6 fatty acid) should be enough to have more GLA and consequently more DGLA.
However, what may look good on paper does not always work as intended in real life. When it comes to the conversion of certain nutrients, enzymes are needed. In this case, the body needs an enzyme called delta-6-desaturase (D6D). This enzyme converts linoleic acid into GLA. This has to happen so that DGLA can ultimately be produced. The problem, however, is that D6D levels decrease with age and due to stress, radiation, sugar, caffeine, trans fats, diabetes and alcohol.
So we can almost certainly assume that many of us suffer from declining D6D levels. Even if you don't eat sugar or drink alcohol, you're likely to suffer from some stress, be exposed to some amount of radiation and of course get older, which decreases your body's ability to produce GLA. This is why with GLA supplementation you can bypass the D6D pathway limiting the rate of GLA production to increase your levels of GLA, which can be quickly converted to DGLA.
Who should consider supplementing with GLA?
I would consider GLA if I were an older strength athlete. This is another pathway to help keep inflammation at bay and improve recovery. For the strength athletes out there who struggle with using non-steroidal anti-inflammatory drugs to treat joint pain, GLA could be a useful approach. A study published in the Journal of Rheumatic Disease showed that GLA has benefits for subjects with rheumatoid arthritis. This study included 3 groups:
- A control group
- A group that took evening primrose oil
- A group that took evening primrose oil and fish oil
GLA is found in vegetable seed oils such as evening primrose oil and borage oil. After twelve months of supplementation, 11 out of 15 subjects from the evening primrose oil group and 12 out of 15 subjects from the evening primrose oil and fish oil group were able to discontinue their pain medication. Only 5 out of 15 subjects from the control group were able to reduce their use of pain medication. Those are pretty darn good results for a vegetable oil! You may not suffer from arthritis, but the cause of common problems like rheumatoid arthritis, osteoarthritis and joint pain is inflammation. GLA is one way to create an anti-inflammatory effect.
Depending on which oil you choose, GLA levels will vary. The dosage used in most studies was around 540 mg of GLA per day. So you don't need huge amounts of GLA to benefit from its positive effects. The bottom line is that GLA is not super promising in terms of fat loss. But if you have a bit of stress, drink a lot of coffee or are getting older, then GLA is a good choice when it comes to keeping inflammation under control.
By Robert Yang
Source: https://www.t-nation.com/supplements/fat-burner-or-money-waster