For many years, pellagra was believed to be an infectious disease promoted by unsanitary conditions. It was common in sanatoriums and orphanages but only among the patients and not the staff. A study of the diets showed that sufferers of pellagra rarely ate high-quality proteins, such as in eggs, milk, and meat.

Question

For many years, pellagra was believed to be an infectious disease promoted by unsanitary conditions. It was common in sanatoriums and orphanages but only among the patients and not the staff. A study of the diets showed that sufferers of pellagra rarely ate high-quality proteins, such as in eggs, milk, and meat.

Introduction of these proteins into the diet cured pellagra.
Which of the following experiments would support the belief that a lack of proteins causes pellagra?
(1) giving fruits that contain vitamin C to animals with pellagra
(2)
reducing the intake of high-quality proteins in healthy animals and monitoring
the results
(3) inoculating healthy individuals with secretions from pellagra skin lesions
(4)
having healthy animals live in an unsanitary environment
(5)
moving animals with pellagra to a sanitary environment

Answer 1

(2) reducing the intake of high-quality proteins in healthy animals and monitoring the results

This experiment would allow researchers to observe the effects of a lack of high-quality proteins on the development of pellagra in otherwise healthy animals. If the animals develop symptoms of pellagra after the reduction in protein intake, it would support the belief that a lack of proteins causes pellagra.