Welcome to my science-based guide that covers the health benefits of CLA.
More precisely, we'll look at whether or not CLA can help prevent (or treat) conditions like cancer, diabetes, cholesterol, fatty liver, triglycerides, inflammation and arteriosclerosis.
Now, as soon as I beign mentioning your health, I'm required (by the law) to give you this warning:
Even if you feel like you're totally healthy, only your doctor can confirm that taking CLA is a good idea for you.
With that out of the way, let's kick things off with one of the most dreaded diseases of all times, cancer.
Can CLA help prevent cancer?
In one study, scientists find out that CLA may help people prevent (and make it a little easier to deal with) cancer.
The problem with this study was, they didn't show which type of CLA worked against cancer.
(The two types of CLA, natural and synthetic, will be covered later in the guide.)
In another study, they confirmed that the best type of CLA for preventing cancer is the natural kind of CLA.
Now, let's take a look on what science has to say about CLA and its influence on some different types of cancer.
CLA and colon cancer
Plenty of studies have proven that CLA both lowers the possibility for getting colon cancer and prevents its growth.
The problem with most of these studies is, they were made on animals. On top of this, the scientists only used the unnatural (synthetic) type of CLA.
But even though the studies done on humans are quite rare...
One study has shown that CLA-rich foods lower the risk of colorectal cancer by 13-34%.
CLA and breast cancer
Scientists found out that CLA can reduce your chances of developing breast cancer by as much as 60%.
Another study showed that CLA can slow the growth and spreading of breast cancer.
Sadly, all of this has only been proven in animal studies (using the unnatural CLA supplement).
So while CLA seems to have some potential against breast cancer, more human studies will need to be done on this.
Time to take a look at how CLA can help out with some other dangerous health issues.
Can CLA help with diabetes?
Diabetes is one of the most widespread health issues in our modern society, so let's see the effect CLA has on this dangerous condition.
Some studies show that CLA helped reduce glucose and insulin levels in the blood (which would be a major benefit for any diabetic patient). Again, this effect of CLA was only proven in animal studies.
On the other hand, a human study has shown that a CLA supplement COULD NOT bring down glucose and insulin levels with type 2 diabetic patients.
So as far as diabetes is concerned, CLA supplements can't be recommended as a part of diabetes treatment.
Let's take a look on one more thing. Does CLA have any positive effect on cholesterol and triglycerides?
CLA and your cholesterol/triglycerides levels
A study done on animals has proven that CLA can bring down total cholesterol and triglycerides.
But a different study, that looked at the benefits of CLA on cholesterol and triglyceride levels showed a completely different result:
When the people in the study took a CLA supplement (the unnatural, synthetic CLA), this actually increased their triglycerides and total cholesterol (which is a very bad thing).
But when the people in the study took natural CLA, their cholesterol and triglycerides didn't change (still, there was no benefit to taking CLA).
The bottom line is, more research needs to be done to be sure what CLA can or can't do for your cholesterol and triglycerides.
On to the connection between arteriosclerosis and CLA.
Can CLA stop arteriosclerosis?
Science says, taking a CLA supplement reduces some of the factors that lead to the development of arteriosclerosis.
Just an interesting side note. In that particular study, scientists used margarine and butter. Both are high-fat foods, but only butter contains a lot of CLA (margarine has no CLA in it).
Now, even though fatty foods in general have been linked to the development of arteriosclerosis, butter was able to reduce the risks of developing arteriosclerosis (because butter is one of the richest natural sources of CLA).
So, if you're ever faced with a choice between butter and margarine, butter is clearly the smarter option.
What about CLA and fatty liver disease?
Fatty liver disease
Fatty liver disease is one of the most common chronic diseases of the liver in the United States, so let's see what CLA can do for this problem.
One study on animals proved unnatural CLA causes fatty liver. On top of this, the unnatural CLA reduced the liver's overall ability to perform its job.
Based on animal studies alone (we have yet to see any human studies done on this), it looks that CLA can't really prevent the development of fatty liver.
In fact, it can actually make things worse.
Until more human studies are done, it's probarly best not to take CLA if you're struggling with fatty liver disease.
Can CLA help you build stronger bones?
According to one study on animals, CLA could help build stronger bones.
It does so by boosting bone formation and by slowing down "bone resorption" (the release of calcium from the bone, which weakens your bones and can lead to osteoporosis over time).
The problem is, when this potential benefit CLA was tested on humans, CLA had absolutely no effect on bone strength.
So even though CLA has been proven to help build stronger bones for animals, it sadly doesn't work for humans.
Let's take a look on one more potential health benefit of CLA.
CLA and inflammatory bowel disease
Research done on animals says that CLA supplementation can protect from inflammatory bowel disease.
Based on animal studies, it looks like CLA could be a good choice for people with inflammatory bowel disease.
But yet again, more research needs to be done on actual humans.
Because, as you saw, in some cases CLA can work wonders for animals while doing absolutely nothing (or even making things worse) for humans.
Time to wrap this part of the guide up.
Summary (actionable takeaways)
A surprisingly high number of studies have been done on the health benefits of CLA.
The good news is, a lot of them have showed at least some potential of CLA for prevention of many different health conditions.
The problem is, most of the scientific research so far has only been done on animals.
Sadly, this makes it pretty much impossible to know whether or not CLA actually works for humans too, for the time being.
All we know at this point, is that natural CLA (as opposed to the unnatural, synthetic CLA found in supplements) seems to be a safer bet.
This guide is actually a part of my complete guide to CLA (go read it if you want more info).
1. McGuire MA, McGuire MK. Conjugated linoleic acid (CLA): a ruminant fatty acid with beneficial effects on human health. Proceedings of the American Society of Animal Science, 1999.
2. Parodi PW. Cow's milk fat components as potential anticarcinogenic agents. J Nutr 1997;127:1055-1060.
3. Bhattacharya A, Banu J, Rahman M, Causey J, et al. Biological effects of conjugated linoleic acids in health and disease. J Nutr Biochem 2006;17:789-810.
4. Ip C, Chin SF, Scimeca JA, Pariza MW. Mammary cancer prevention of conjugated dienoic derivative of linoleic acid. Cancer Res 1991;51:6118-6124.
5. Visonneau S, Cesano A, Tepper SA, Scimeca JA, et al. Conjugated linoleic acid suppresses the growth of human breast adenocarcinoma cells in SCID mice. Anticancer Res 1997;17(2A):969-73.
6. Houseknecht KL, Vanden Heuvel JP, Moya-Camarena SY, Portocarrero CP. Dietary conjugated linoleic acid normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochem Biophys Res Commun 1998;244(3):678-82.
7. Sher J, Pronczuk A, Hajri T, Hayes KC. Dietary Conjugated Linoleic Acid Lowers Plasma Cholesterol during Cholesterol Supplementation, but Accentuates the Atherogenic Lipid Profile during the Acute Phase Response in Hamsters. Jour Nutr 2003;133(2):456-460.
8. Tricon S, Burdge GC, Kew S, Banerjee T, et al. Opposing effects of cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid on blood lipids in healthy humans. Am J Clin Nutr 2004;80:614-20.
9. Nakamura YK, Flintoff-Dye N, Omaye ST: Conjugated Linoleic Acid Modulation of Risk Factors Associated With Atherosclerosis. Nutr Metab. 2008, 5: 22-30. 10.1186/1743-7075-5-22.
10. Lasa A, Simón E, Churruca I, Fernández-Quintela A1, et al. Effects of trans-10,cis-12 CLA on liver size and fatty acid oxidation under energy restriction conditions in hamsters. Nutrition 2011;27(1):116-121.
11. Watkins BA, Seifert MF. Conjugated linoleic acid and bone biology. J Am Coll Nutr 2000;19:478S-486S.
12. Doyle L, Jewell C, Mullen A, Nugent AP, et al. Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men. Eur J Clin Nutr 2005;59:432-440.
13. Bassaganya-Riera J, Hontecillas R. Dietary conjugated linoleic acid and n-3 polyunsaturated fatty acids in inflammatory bowel disease. Curr Opin Clin Nutr Metab Care 2010;13(5):569-73.