What is CLA?

• Conjugated linoleic acid (CLA) is a type of polyunsaturated fatty acid found naturally in various animal products, such as meat and dairy products, particularly from grass-fed animals.
• It is also available in supplement form.
• CLA is made up of a group of isomers of linoleic acid, a type of omega-6 fatty acid.

What are the advertised health benefits of CLA?

Proposed mechanism of action of CLA on weight loss:

CLA is proposed to influence weight loss through several mechanisms:

1. Modulation of Lipid Metabolism:
   • CLA may influence lipid metabolism, including fatty acid oxidation, lipolysis (breakdown of fat), and lipogenesis (production of fat).
   • It is suggested that CLA may enhance fat oxidation and inhibit fat storage, leading to a reduction in body fat mass.
2. Alteration of Adipocyte (Fat Cell) Function:
   • CLA may affect adipocyte function by influencing gene expression and signaling pathways involved in fat metabolism.
   • It has been proposed that CLA may increase the expression of genes involved in fat oxidation and decrease the expression of genes involved in fat storage in adipocytes.
3. Regulation of Energy Expenditure:
   • CLA supplementation may increase energy expenditure, possibly by stimulating metabolic rate or thermogenesis (production of heat by the body).
   • This could lead to greater calorie expenditure and contribute to weight loss.
4. Appetite Regulation:
   • Some studies suggest that CLA supplementation may affect appetite regulation and satiety, leading to reduced food intake and calorie consumption.
   • However, the evidence regarding the effects of CLA on appetite is mixed and not fully understood.
5. Modulation of Hormones and Signaling Pathways:
   • CLA may influence various hormones and signaling pathways involved in metabolism and appetite regulation.
   • For example, it has been suggested that CLA may affect the production and activity of hormones such as leptin, ghrelin, and adiponectin, which play roles in energy balance and appetite control.

But does it Practically do what it claims to do?

Numerous studies have been done analyzing the effect of CLA on weight loss. To name a few:

• Title: Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans
  • Authors: Blankson, H., Stakkestad, J.A., Fagertun, H., Thom, E., Wadstein, J., & Gudmundsen, O.
  • Journal: The American Journal of Clinical Nutrition
  • Year: 2000
• Title: Conjugated linoleic acid supplementation for twelve weeks increases lean body mass in obese humans
  • Authors: Kamphuis, M.M.J.W., Lejeune, M.P.G.M., Saris, W.H.M., & Westerterp-Plantenga, M.S.
  • Journal: Journal of Nutrition
  • Year: 2003
• Title: Effect of conjugated linoleic acid on body fat accretion in overweight or obese children
  • Authors: Moya-Camarena, S.Y., Vanden Heuvel, J.P., & Blanchard, S.G.
  • Journal: The American Journal of Clinical Nutrition
  • Year: 1999
• Title: Conjugated linoleic acid supplementation alters the 6-mo change in fat oxidation during sleep
  • Authors: Zambell, K.L., Keim, N.L., Van Loan, M.D., Gale, B., Benito, P., & Kelley, D.S.
  • Journal: The American Journal of Clinical Nutrition
  • Year: 2000
• Title: The effect of conjugated linoleic acid supplementation after weight loss on body weight regain, body composition, and resting metabolic rate in overweight subjects
  • Authors: Gaullier, J.M., Halse, J., Høye, K., Kristiansen, K., Fagertun, H., Vik, H., … & Gudmundsen, O.
  • Journal: International Journal of Obesity
  • Year: 2007
• Title: Conjugated linoleic acid reduces body fat mass in overweight and obese humans
  • Authors: Gaullier, J.M., Halse, J., Høye, K., Kristiansen, K., Fagertun, H., Vik, H., … & Gudmundsen, O.
  • Journal: The Journal of Nutrition
  • Year: 2007

The summary of the results of these studies are:

1. Reduction in Body Fat Mass:
   • The study by Blankson and others (2000) found that CLA supplementation over one year resulted in decreased body fat mass in overweight individuals.
   • The study by Gaullier and others (2007) observed a reduction in body fat mass in overweight and obese humans with CLA supplementation.
2. Increase in Lean Body Mass:
   • CLA supplementation was associated with an increase in lean body mass in some studies.
   • The study by Kamphuis and others (2003) found that CLA supplementation for twelve weeks led to increased lean body mass in obese individuals.
3. Effect on Fat Oxidation:
   • The study by Zambell and others (2000) investigated the effects of CLA supplementation on fat oxidation during sleep.
   • They observed that CLA supplementation may increase fat oxidation during sleep, potentially contributing to weight loss.
4. Body Weight Regulation:
   • The study by Gaullier and others (2007) found that CLA supplementation reduced body weight regain after weight loss, indicating a potential role in body weight regulation.
   • However, the specific mechanisms underlying this effect were not fully elucidated.

How much CLA can you consume in a day?

• There is no Required Daily Allowance (RDA) for CLA set by FDA as CLA is not an essential nutrient because there is no specific requirement for it to prevent deficiency.
• The typical doses used in the above research studies range from 3 to 6 grams per day which was administered in split dose of 1 to 2 grams with every meal.
• CLA supplements usually come in softgel capsules, with each capsule containing 1,000 mg (1 gram) per capsule.
• CLA is primarily found in foods derived from ruminant animals, such as beef, lamb, and dairy products like milk, cheese, and butter.

What are the side effects of CLA when consumed in higher doses?

1. Gastrointestinal Issues:
   • Some people may experience digestive discomfort such as diarrhoea, stomach upset, or nausea when taking CLA supplements.
   • These gastrointestinal side effects are more common when taking higher doses.
2. Insulin Resistance:
   • There is some concern that CLA supplementation may worsen insulin resistance, particularly in individuals who are obese or have metabolic disorders such as diabetes.
   • However, research on this topic has yielded mixed results, and more studies are needed to understand the potential effects of CLA on insulin sensitivity.
3. Potential Liver Toxicity:
   • In rare cases, high doses of CLA supplements may lead to liver toxicity or damage.
   • However, such cases are uncommon, and the exact mechanism of how CLA might affect the liver is not well understood.
4. Allergic Reactions:
   • Some individuals may be allergic to CLA or other ingredients present in CLA supplements.
   • Allergic reactions can range from mild symptoms such as itching or hives to more severe reactions such as difficulty breathing or anaphylaxis.

Verdict:

• While CLA supplementation may offer potential benefits for weight management, such as reductions in body fat mass and improvements in body composition, the effects are often modest and may not be significant independently.
• It’s best utilized as a complementary approach alongside a healthy diet and regular exercise rather than solely relied upon for weight management.