Nutrition researchers want to study the link between a high-fiber diet and the reduced risk of colon cancer. Describe how they could carry out each of the following types of studies:

Answer 1

a . Interventional study
The researchers could have 2 groups of people who eat a preplanned diet. The control group eats a typical diet that has 10-15 grams of fiber per day. The experimental group eats a diet that has more high-fiber foods, and they consume 25-30 grams per day for a given amount of time. The researchers could have the subjects fill out questionnaires or even have them go in for colonoscopies to see the effects of high fiber intakes on the walls of their colons. The two groups would be compared to see the effects of fiber on the health of their colon.
b. Epidemiologic study
The researchers would observe a group of people who tend to eat a higher-fiber diet versus a group of people who tend to eat a lower-fiber diet. The researchers could have the groups of people fill out health assessment surveys to determine whether their diet can be correlated with a higher or lower risk of colon cancer.
c. Laboratory study
The researchers would work with animals such as rats or mice in the lab and would manipulate their diets. One group of animals would receive a high-fiber diet and the other group would receive a low-fiber diet. After a given amount of time, the researchers could examine the colons of each group of animals to determine whether there is any increase in the rate of cancer. By manipulating the animals' diets, the researchers could determine whether the increase of cancer is due to the level of fiber in the diet.