Rodent malaria in rats exacerbated by milk protein, attenuated by low-protein vegetable diet.

Young male Wistar rats were fed a purified, vegetable, low-protein diet containing 6% protein from maize gluten and 2% from soy protein isolate, or comparable diets in which maize gluten was replaced partly or completely by the equivalent amount of a milk protein concentrate. Diets with adequate protein level (16% or 22%) served as a control. At 21 or 31 days of age, the rats were infected with 3000 or 100000 erythrocytes parasitized with Plasmodium berghei. Results reported include body weight, mortality, paralysis and parasitaemia. Dietary replacement of part of the maize gluten protein by milk protein increased weight gain, but aggravated the malaria, as shown by increases in parasitaemia, paralysis and mortality. The aggravating effect of milk protein was dose-dependent. With only 4% milk protein in an 8% total protein diet, the disease symptoms were nearly as severe as with diets adequate in protein level. With a vegetable-only 8% protein diet symptoms were considerably less severe.