CLA, conjugated linoleic acid, is found in high-fat dairy food and beef. However, because many people have cut back on their intake of high fat dairy products, and cows raised on oats, barley and hay rather than grass contain far less CLA, people may not be ingesting enough of this valuable nutrient.
The CLA study, published in the October 2005 American Journal of Clinical Nutrition, confirms that CLA has a protective effect against colon cancer. The mamoth fifteen year-long study included 60,708 women ranging in age from 40 - 76. The scientists assessed the consumption of high-fat dairy foods (and CLA) in these women from 1987 to 1990, and again in 1997.
During the follow-up of nearly 15 years, 798 of the women developed colorectal cancer. The researchers found that those with the lowest risk of developing colorectal cancer were the women who consumed 4 servings or more of high-fat dairy foods per day. The women who consumed less than 1 serving per day had the highest risk. Each increment of 2 servings of high-fat dairy foods per day resulted in a 13 percent reduction in colorectal cancer risk. In addition, the greater the CLA intake, the less the risk of colorectal cancer.
The researchers concluded that high intakes of high-fat dairy foods [and CLA] may reduce the risk of colorectal cancer.
Susanna C Larsson, Leif Bergkvist, and Alicja Wolk. High-fat dairy food and conjugated linoleic acid intakes in relation to colorectal cancer incidence in the Swedish Mammography Cohort. Am J Clin Nutr 2005 82: 894-900.