CLA & The Paleo Diet
Concluding my focus on common deficiencies, this week turns to CLA.
CLA stands for Conjugated Linoleic Acid and is the good trans-fat that occurs naturally in dairy and meat products – especially when animals have been grass-fed, another plus for the Paleo diet. In the stomach of animals such as the goat, sheep or cows millions and millions of tiny pieces of bacteria help the animal to digest its food. They also help to convert dietary linoleic fatty acids into saturated fatty acids. While this conversion takes time and several steps, one of those steps is to create CLA, some of this never actually gets fully saturated and will show up instead in the animals milk fat and body.
28 different CLA isomers – or structural arrangements of the molecules show in CLA rich animal fat. This is very complex and different from the trans-fats created by partially hydrogenating vegetable oils. It is those lab created trans-fats that have a negative metabolic and health effect, while the CLA isomers you get from grass fed dairy and meat is more beneficial.
CLA has been touted as the “belly busting” trans fat with research in 2007 showing that in rats, supplementing their diets with CLA did not cause them to lose whole body fat, but it was found they became more insulin sensitive. When it came to supplementing CLA in mice diets it did cause rapid weight loss, but the increase in hepatic fat accumulation left the mice insulin resistant.
Many people have taken CLA as a supplement and it did seem to work for weight loss, but while the weight loss was good, at the moment we are not really sure what else it does to the body. Research into this further on different animals may help us better understand if there are any additional effects on humans. Are we more like mice or rats?
The one thing that these studies did show was that hepatic fat accumulation or loss and body fat accumulation or loss is not always in the same direction. We are seeing hepatic fat loss but no weight loss and hepatic fat gain with rapid weight loss. Those who follow low carb diets insisting that this metabolic advantage allows them to eat thousands of calories and lose weight will love the little mouse’s result! While the study on the mouse is quite well known amongst those in the carb circle with the mouse eating as much as it wants without losing or gaining weight, this metabolism does come at a price – profound liver damage.
Tests were carried out to see what effect dietary supplements of CLA would have on the body mass index, and body fat distribution. 40 volunteers participated in a 12 week double blind study some received a CLA while other received olive oil. Body fat and abdominal and hepatic fat content was assessed with an overall finding that showed CLA supplements did not show any significant change in the volunteers BMI index or in their total body fat.
Best Natural Sources of CLA in a Paleo Diet
One of the key advantages of the Paleo lifestyle is its emphasis on whole, nutrient-dense foods — which happen to be the best way to obtain CLA. Rather than relying on synthetic supplements, which come with potential risks and inconclusive evidence, it's far more beneficial to get your CLA directly from food sources. But not all animal products are equal.
Why Grass-Fed Really Matters
Grass-fed and pasture-raised animals contain significantly higher levels of CLA than grain-fed counterparts. When animals consume a natural diet of pasture grasses (instead of soy, corn or grain-based feed), their digestive bacteria convert linoleic acid into more beneficial CLA isomers. This results in higher-quality meat and dairy with measurable health benefits for the consumer.
If you're eating beef, lamb, or goat as part of your Paleo plan, aim to source it from farms that guarantee grass-fed and finished practices. Similarly, full-fat grass-fed dairy (for those following a more Primal or flexible version of Paleo) will also yield higher CLA levels, particularly in butter, ghee and cream.
CLA-Rich Paleo Foods to Include
- Grass-fed beef – Particularly cuts with visible fat and marbling
- Pastured lamb – Lamb naturally contains high CLA levels, especially from animals reared on Australian pasture
- Ghee or butter – When sourced from grass-fed cows, these fats are rich in both CLA and butyrate
- Full-fat raw cheese and cream – Ideal if tolerated, especially when made from the milk of pastured animals
- Wild game meats – Venison and kangaroo may also contain beneficial CLA, depending on their forage
Potential Health Benefits of CLA from Whole Foods
Unlike synthetic CLA supplements, naturally occurring CLA in whole foods appears to offer a range of benefits — without the potential drawbacks seen in clinical trials using isolated isomers. When consumed as part of a varied diet, CLA from grass-fed animal fat has been linked with:
- Improved immune response – CLA may help modulate inflammation and enhance immune cell activity
- Better blood sugar control – Animal studies suggest CLA may improve insulin sensitivity, though results are mixed in humans
- Reduced tumour growth – Preliminary research indicates CLA may have anti-carcinogenic effects in certain types of cancers
- Improved cholesterol profile – Some studies associate CLA-rich dairy fat with healthier HDL:LDL ratios
That said, more research is needed, particularly on the long-term effects of CLA-rich diets in humans — but getting these benefits from food rather than pills remains the safest and most evolutionary aligned option.
CLA and Weight Loss: Separating Hype from Reality
It’s easy to see why CLA gained popularity in the weight loss industry. Some studies in mice showed remarkable fat loss and changes in body composition — but translating these findings to humans hasn’t been straightforward. The mixed human results, especially with synthetic CLA supplements, are a reminder that what works in a lab doesn’t always replicate in real life.
Many supplement companies still tout CLA as a fat-burning miracle. But the reality is, in human trials, CLA appears to offer at best a modest reduction in body fat — often without a change in BMI or overall weight. More importantly, these synthetic supplements often use only one or two isomers of CLA, potentially missing out on the benefits of the full range found in real food.
How CLA Fits Into Your Paleo Strategy
If you’re already eating a Paleo diet rich in grass-fed meats, pastured fats, and avoiding processed foods and refined oils, chances are you’re already getting enough CLA to reap its potential benefits. There’s no need to supplement unless a specific deficiency or clinical condition has been diagnosed.
In fact, the real power of CLA lies in its synergy with other nutrients in whole foods — such as omega-3 fatty acids, fat-soluble vitamins (A, D, E, K2), and antioxidants. A well-constructed Paleo plate naturally delivers these in balance, supporting a healthier metabolism, improved energy, and possibly more stable body composition.
Tips for Boosting CLA Naturally
- Choose grass-fed and finished meats over grain-fed whenever possible.
- Incorporate animal fats like tallow, ghee and grass-fed butter in cooking, rather than seed oils.
- Support local and regenerative farms — often the best source of nutrient-dense, CLA-rich foods.
- If you include dairy, opt for raw or low-processed full-fat options from grass-fed sources.
- Reduce reliance on processed low-fat meats and factory-farmed cuts — these offer less nutritional return overall.
Final Thoughts
CLA, like many other nutrients found in natural animal fats, is a powerful example of how traditional eating patterns can offer benefits that modern diets often miss. While the supplement industry has tried to isolate and commercialise CLA as a magic bullet, nature continues to do it best — delivering CLA as part of a complex nutritional package in high-quality animal foods.
If you're following Paleo with an emphasis on real food and ethically raised meat, you're already on the right track. Supplementation may still be explored for specific therapeutic reasons, but when it comes to sustainable, safe intake — your dinner plate is your best ally.
Have you noticed a difference when switching to grass-fed meat and pastured fats? Share your story — I’d love to hear how it’s impacted your energy, weight, or overall health.
