Conjugated Linoleic Acid: How CLA Burns Fat and Boosts Your Immune System
By: Emma Rose
- Conjugated Linoleic Acid (CLA) is a polyunsaturated fat found in linoleic acid, an essential fatty acid found mostly in plant oils.
- It’s one of the magic ingredients that make grass-fed butter and meat so incredible for boosting your physical performance.
- CLA helps your body build muscle rather than store fat and has anti-inflammatory properties. It may even help prevent cancer.
- The best natural sources of CLA are grass-fed beef, butter and full-fat dairy. Animals need real grass and greens in their diets to make CLA, so it’s important to go for grass-fed sources.
If you’ve been following the Bulletproof Diet, or looking for a way to burn more fat on a healthy, whole food diet, you may have come across CLA, or conjugated linoleic acid. It’s one of the magic ingredients that make grass-fed butter and meat so incredible for boosting your physical performance.
As one of the few naturally occurring, healthy trans fats, this little fatty acid can burn fat, build muscle, and fight cancer. What’s better? If you’re not already eating conjugated linoleic acid for its benefits, it’s simple to incorporate from delicious, whole-food sources.
As if you needed another reason to love the benefits of grass-fed butter.
What is CLA?
Conjugated Linoleic Acid (CLA) is a polyunsaturated fat found in linoleic acid, an essential fatty acid found mostly in plant oils. Naturally, CLA is a product of digestion by microbes in the first stomach (rumens) of grass-eating animals such as cows, so is found mainly in grass-fed beef and dairy products. Not only is CLA easy to find on the Bulletproof Diet, it’s also connected to fighting cancer, and helping your body build muscle rather than store fat.
Conjugated linoleic acid is an omega-6 fatty acid. Diets high in omega-6 tend to be inflammatory, which is why you may have heard to avoid omega-6 rich foods. Your body actually needs some omega-6 from food sources, but in a much smaller dose than the standard American diet dishes out.
Fortunately, the anti-inflammatory properties of CLA cause it to behave more like an omega-3 in the body. The two main active isomers, or types, of CLA are the 9,11 isomer, and the 10,12 isomer, both naturally found in CLA-rich foods.
What are the benefits of CLA?
CLA burns body fat and helps with weight loss
Say it with me: Butter burns fat! The most well-established benefit of CLA is its fat-fighting power. Successful human studies show that doses of 3 to 4 grams daily build muscle mass and promote body fat loss in healthy, overweight, and obese participants.
Conjugated linoleic acid can affect your weight loss through several pathways. Several studies show that the 10,12 CLA isomer acts on PPAR-gamma receptors to inhibit the genes responsible for fat storage and adipocyte (fat cell) production, preventing weight gain from the start. (Bonus points: reducing fat storage also boosts your liver performance, and can reduce the fatty deposits behind atherosclerosis.) At the same time, CLA increases your body’s energy expenditure, helping you to burn fat faster than you build it.
Human studies also show that CLA can increase satiety (your feeling of fullness) — part of the reason grass-fed butter is so perfect in Bulletproof Coffee. The theory here is that 10,12 CLA actually decreases the expression of certain hunger-signalling factors in the hypothalamus area of your brain.
Fights inflammation and boosts immune system
The anti-inflammatory functions of conjugated linoleic acid, like other inflammation-busting foods, help it support nearly every system in your body. Studies show that CLA plays a role in regulating your body’s inflammatory and immune responses, as well as boosting liver health to support detoxification.
Conjugated linoleic acids bolster the immune system and helps build resistance to infections, inflammatory disorders and other immune system imbalances like autoimmune disease and allergies.
In one study from The Journal of Nutrition, the anti-inflammatory properties of both CLA isomers successfully reduced inflammation in arthritic mice. It may also benefit people suffering from asthma and allergies by reducing over-responsive airway inflammation.
These results suggest that consuming CLA could benefit other chronic inflammatory conditions.
CLA may help prevent cancers
One of the first findings to bring conjugated linoleic acid into the health scene was its potential as a cancer prevention agent, especially in the fight against breast cancer. In animal studies, supplementing with CLA reduced the number of tumors in rats. It directly limited the process of cancer formation by lowering the susceptibility of tissues to cancer, and inhibiting the metastasis (spreading) and adhesion of new tumors. This cancer-busting fatty acid has also been shown to reduce the formation of new blood vessels needed to feed a tumor, and up-regulate a gene called PTP gamma, known for its role in suppressing tumors in breast, kidney and lung cancer. 
CLA and diabetes, blood sugar & insulin
A study in the American Journal of Clinical Nutrition found higher concentrations of 9,11 CLA in adipose tissue was associated with a lower risk of diabetes. Of course, if you’re eating a diet rich in CLA, you’re probably eating less of the toxic processed meat products linked to diabetes.
Many supplements or health sites may lead you to believe that CLA improves insulin response and blood sugar control, however the science behind this claim falls short. In fact, many trials show that in high doses, isomer 10,12 CLA may actually increase insulin resistance, where 9,11 appears to have no effect. One interesting study showed that supplementing CLA together with olive oil kept the benefits, but prevented the insulin resistance seen from CLA supplementation alone! By keeping sugar swings low, a low-glycemic diet may also help you to safely reap the other dietary benefits of CLA.
Builds (and maintains) strong bones
Another advantage of CLA comes from its bone-strengthening and protective effects. Dietary CLA significantly prevents losses in bone density by both increasing the body’s signals to absorb calcium (parathyroid hormone and calcitriol), as well as reducing the activity of osteoclasts, the cells responsible for eating away at your bones when calcium is low. Who knew that butter could bust osteoporosis?
Sounds good. Where do I find CLA?
The best perk of CLA is that it’s ridiculously easy to find on the Bulletproof Diet. The best natural sources of CLA are grass-fed beef, butter and full-fat dairy, with smaller doses found in veal, lamb, turkey and fish. Animals need real grass and greens in their diets to make CLA, so it’s important to go for grass-fed sources. Not only does eating grass-fed beef or dairy give you significantly higher omega-3s and CLA, you also get more vitamins K, D, and A, and less toxins than conventional, grain-fed options. ]
A four-ounce serving of grass-fed beef contains around 433 mg of CLA, while grass-fed whole milk contains up to 240 mg.  Grass-fed dairy products and pastured eggs are excellent vegetarian sources of CLA.
How much should I take?
While most of the effective human trials studying CLA gave participants between three to four grams daily, there isn’t yet a consensus on the best dosage for your diet. On average, non-vegetarian men and women on a standard American diet (SAD) consume 152 and 212 mg daily, although studies show this isn’t enough to bring the benefits. CLA supplements vs whole foods:
With all these amazing findings, CLA supplements are also gaining popularity. Most of the studies on CLA use direct supplements rather than whole foods; after all, if you feed someone grass-fed beef, how could you know if their outcome is due to CLA, or another of its beneficial compounds?
Outside of the lab, whole food sources are your safest route for dietary CLA, since most supplements are made from processing unhealthy vegetable oils such as safflower or sunflower oils. Plus, who doesn’t like an excuse for more butter?
Why Grass-Fed Meat is Healthier than Grain-Fed