Trans Fats Linked to Pre-Cancerous Colon Growths

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Trans Fats Linked to Pre-Cancerous Colon Growths

A high intake of trans fats could increase colon cancer risk, according to

new research published in the American Journal of Epidemiology.

People who ate the most trans fatty acids were more likely to have

pre-cancerous growths or polyps in their colons than those who consumed the

least, Dr. C. Vinikoor of the University of North Carolina in Chapel

Hill and colleagues found. " These results provide further support for

recommendations to limit consumption of trans-fatty acids, " they conclude.

Trans fats are formed by processing vegetable oils to increase their

shelf-life, and are found in many baked goods, crackers, snacks and other

packaged foods. Eating them increases levels of " bad " LDL-cholesterol, and

hence heart disease risk. US food producers are now required to list the

amount of trans fat contained in their products, and health authorities

recommend people avoid eating trans fats entirely.

While there has been little research on whether trans fats boost colorectal

cancer risk, there are many possible ways that they could do so, for example

by changing the normal balance of fatty or bile acids in the colon, Vinikoor

and her colleagues say.

To investigate a possible link, they looked at 622 people who had

colonoscopies at University of North Carolina Hospitals in 2001 and 2002.

Study participants were interviewed about their diet, physical activity and

other health issues within 12 weeks of having the screening test.

People in the top fourth based on trans-fatty acid consumption, most of whom

took in 6.54 grams daily, were 86 percent more likely to have colon polyps

than those in the bottom quartile for trans fat intake, for whom median

intake was 3.63 g, the researchers found. There appeared to be a threshold

effect, with no increased risk seen for people in the bottom three quarters

of fatty acid consumption.

Among the 38.5 percent of study participants found to have colon polyps,

average trans fatty acid intake was 4.97 g, while most consumed 4.12 g.

Average intakes for people who were free of the colon growths was 4.42 g,

while the median was 3.61 g.

These results suggest that consumption of high amounts of trans-fatty acid

may increase the risk of colorectal polyps, the researchers write, adding

that the findings also back current recommendations to limit trans fat

intake.

SOURCE: American Journal of Epidemiology, August 1, 2008.

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