Conjugated linoleic acid (CLA) lies in the category of essential fatty acids. It is basically an omega-6 polyunsaturated fatty acid. CLA is essential to be provided through diet to maintain health. This is because it is present in the structure of plasma membranes giving them flexibility and support. Furthermore, it also prevents cardiac diseases, cancer, and lower body fat, etc. According to Linus Pauling Institute, the daily intake of CLA should be 3 grams per day. So, being so important for sound health we have to know about sources of CLA. This article is all about sources of CLA.
There are multiple sources of CLA, but the richest sources are eggs, beef, and milk, etc. Moreover, it is also present in pork, vegetable oils, and poultry, etc. Given below is the detailed description of some rich sources of CLA:

Beef:

According to research in "Journal of Dairy Science" in October 1999, beef is the most usual source of CLA. However, the concentration of CLA in beef is largely dependent on the food the cow eats. Cows eating grass will have more CLA content in their meat while cows who are fed on corn diet will have less CLA content in their meat. It is because omega-3 fatty acid is present in the grass but absent in corn. Normally beef has 4.3 mg of CLA in each gram of fat.

Milk:

Milk is also a rich source of CLA particularly milk of those cows who are fed on grass. In 2004 in "Circulation" it was demonstrated that those cows who were fed on the grass at high altitudes provide milk with more concentration of CLA than the other cows. This result is because of more omega-3 fatty acid concentration in the grass of high altitudes. Since CLA is present in milk fat, therefore, purified or processed milk like low-fat or non-fat milk will have CLA in lesser quantity. Pure cow milk contains 5.5 mg of CLA in each gram of fat.

Eggs:

Eggs are also a rich source of CLA. This quantity of CLA is more in eggs of those hens who are fed on grass. CLA is present in the egg yolk. "Food Chemistry" in August 2004 published that even after the eggs are fried, their CLA content remains. Moreover, Linus Pauling Institute experimented with fortifying of eggs with CLA. Then found the effects of these eggs in hamsters. Such eggs proved more effective with no known adverse effects. After this successful experimentation, it is proposed that such eggs should be recommended for humans to enhance the quantity of CLA in the diet. This is because rich sources of CLA are not sufficient in the diet of Western people.