Soy protein diet increases skilled forelimb reaching function after stroke in rats

Abstract

Stroke is a leading cause of lasting disability. Dietary strategies aimed at increasing post-stroke outcomes are lifestyle alterations which could be easily implemented by people at risk of occlusive stroke. Soy diets have been demonstrated to provide some benefits in the short term following stroke, but longer time periods have not been studied. Further, carefully defined diets containing soy protein isolates have not been investigated. In the current study, male Long Evans Hooded rats were fed semi-purified diets containing either sodium caseinate or soy protein isolate. Rats were trained to perform the skilled forelimb reaching task and subsequently underwent unilateral middle cerebral artery occlusion (MCAO) to induce a stroke lesion. After stroke, rats remained on the same diet and were tested daily for a period of 8 weeks to observe their performance on the skilled forelimb reaching task. In the first week following stroke, rats receiving the soy protein-containing diet (SP) demonstrated less severe reaching deficits than rats fed the Na caseinate-containing diet (CAS) (p<0.05). These results suggest that a soy protein-based diet provides significant protection from neurological damage following MCAO stroke in rats.