Wizard of Vitamins

Conjugated Linoleic Acid Vitamin

What is Conjugated Linoleic Acid?

Conjugated linoleic acid (CLA) is a slightly altered form of the essential fatty acid linoleic acid.

Conjugated Linoleic Acid in Diets

CLA is found mainly in dairy products and also in beef and poultry, eggs, and corn oil. Bacteria that live in the intestine of humans can produce CLA from linoleic acid, but supplementation of a rich source of linoleic acid did not produce increases in blood levels of CLA in one human study. CLA is available as a supplement.

Conjugated Linoleic Acid Medicinal Treatments

Athletic performance (body composition and strength) Cancer prevention (lung, colon, breast)

Known Consequences of Conjugated Linoleic Acid Deficiency

No deficiencies of CLA are reported or believed to occur, since it is not an essential nutrient.

Conjugated Linoleic Acid Recommended Dosages

Animal research uses very large amounts, equivalent to several grams per day for humans. Until human research is conducted with CLA, the appropriate amount to take of this nutrient remains unclear.

Conjugated Linoleic Acid Side Effects

Overweight volunteers who took 4.5 grams of CLA per day for one year had an increase in their blood levels of lipoprotein(a), a risk factor for heart disease. In a double-blind study of human volunteers, supplementation with 4.2 grams per day of a mixture of cis-9,trans-11 CLA and trans-10,cis-12 CLA for three months increased the concentration of C-reactive protein, another risk factor for heart disease. In a study of healthy volunteers, supplementing with 4.5 grams of CLA per day for 12 weeks caused an impairment of blood vessel function (endothelial dysfunction), which is believed to be associated with an increased risk of heart disease. Taken together, these findings suggest that long-term use of CLA could increase the risk of developing heart disease. In a double-blind study of people with type 2 diabetes, supplementing with 3 grams of CLA per day for eight weeks significantly increased blood glucose levels by 6.3% and decreased insulin sensitivity. A reduction in insulin sensitivity was also seen in a study of overweight men without diabetes after treatment with 3 grams of CLA per day for three months, although in a study of young sedentary men, 4 grams of CLA per day for eight weeks improved insulin sensitivity. Thus, although the studies are conflicting, CLA may be harmful for some people who have, or are at risk of developing, diabetes. One unpublished human trial reported isolated cases of gastrointestinal upset. At the time of writing, there were no well-known drug interactions with conjugated linoleic acid.