Dietary factors affecting the incidence of dietary fat-induced myocardial lesions

Histological study of ventricular muscle was conducted on Sprague-Dawley male rats fed diets containing 20% (w/w) of either soybean oil, low erucic acid rapeseed oil or high erucic acid rapeseed oil. Purified diets providing two levels of intake for choline and inositol or magnesium were fed for 16 weeks to determine whether increased intake of these nutrients reduced myocardial lesion incidence. Diets containing high erucic acid rapeseed oil resulted in a high incidence of degenerative focal myocardial lesions, whereas low erucic acid rapeseed oil feeding resulted in less severe cardiopathological changes. Dietary supplementation providing 0.475% (w/w) choline and 0.635% (w/w) inositol reduced incidence of myocardial lesion for both rapeseed oil treatments indicating that lesion incidence may also be altered by the nutrient composition of the purified diet. Nutritional adaptation by increasing the animals dietary fat intake from 6% (w/w) to 20% (w/w) over an 8-week period had no effect on lesion incidence.