CLA (Conjugated Linoleic Acid)

CLA (Conjugated Linoleic Acid) is a naturally occurring polyunsaturated fatty acid found mainly in meat and dairy products from ruminant animals — especially grass-fed cattle. It is a conjugated form of linoleic acid (omega-6) with different geometric configurations. Supplemental CLA is produced industrially from sunflower oil by alkaline isomerization, generally in the c9,t11 and t10,c12 forms. Each isomer has distinct biological effects — and not always beneficial ones.

• Possible body fat reduction — especially abdominal fat
• Possible lean mass increase
• Antioxidant and anti-inflammatory action
• Possible immune support
• The c9,t11 isomer (naturally present in food) has a more favorable profile

• •People in body definition phase seeking complementary alternatives
• •Those who already have a well-structured diet and training and seek marginal additional support
• •People interested in body composition who consume few grass-fed dairy and meat products

3–6g per day, split into 3 doses with main meals. Studies generally use 3.2–6.4g/day. Results are modest and appear after 12+ weeks of continuous use.

CLA is a supplement with modest evidence and inconsistent results in humans. The difference between isomers is important: c9,t11 (predominant in natural foods) has a more favorable profile; t10,c12 (predominant in industrial supplement) is responsible for body composition effects, but also for potential adverse effects — insulin resistance and inflammation in some studies. For fat loss, caloric deficit + protein + training are infinitely more effective. CLA can be a marginal complement for those who already have everything optimized, but is not a priority.

Evidence for CLA in humans is mixed and modest. Meta-analyses show an average fat reduction of 0.09kg per week — statistically significant but clinically irrelevant in practice. Animal studies show more expressive results than in humans. The t10,c12 isomer is responsible for body composition effects but has also been associated with insulin resistance, hepatic inflammation and HDL reduction in some human studies. The c9,t11 isomer from food has a safer profile. Most supplements contain a 50:50 mixture of the two isomers.

May cause gastrointestinal discomfort (nausea, diarrhea). The t10,c12 isomer has been associated with insulin resistance and inflammation in some studies. May reduce HDL (good cholesterol) in some people. Not recommended during pregnancy or breastfeeding.