Methods May Affect Fiber-Cancer Link

Does eating a lot of fiber decrease people’s risk of getting colon cancer? Research studies have reached different conclusions. But a new study suggests that the results may depend on how people report what they eat. The study included 579 people who developed colorectal cancer and 1,996 people who did not. Everyone kept food diaries, writing down what they ate for four to seven days. Most people also filled out questionnaires that asked what foods they had eaten. People whose food diaries showed that they ate more fiber had a lower risk of colon cancer. Those who ate 24 grams per day were 30% less likely to develop cancer than those who ate 10 grams per day. This means there were about 7 colorectal cancers in the high-fiber group for every 10 cancers in the low-fiber group. But the questionnaires showed different results.