1. Since 100% stroke-prone spontaneously hypertensive rats (SHRSP) develop cardiovascular diseases (CVD) spontaneously, they are the best models for experimental studies on CVD prevention. Previous studies have proven that stroke can be prevented by improving diets such as sodium (Na) restriction, potassium (K) supplementation and, feeding of animal or vegetable proteins, some amino acid and fatty acids and dietary fibres. 2. Recent studies in SHRSP have further confirmed the effectiveness of CVD prevention of the following dietary components. 3. Studies on SHRSP repeatedly demonstrated that the adverse effect of Na was counteracted by K, which reduced stroke incidence. Even a 1 min reduction in dietary Na/K ratios (from 0.93 to 0.61) delayed the development of stroke in SHRSP given 1% NaCl water for drinking. 4. Excess NaCl intake affected the development of stroke more adversely in SHRSP than Na citrate excess. 5. An increase in dietary Ca (from 0.6 to 1.2 or 1.6%) effectively attenuated the development of hypertension, prevented stroke and prolonged life-span in salt-loaded SHRSP, whereas additional dietary Mg (from 0.2 to 0.8%) did not affect BP levels. 6. The quality of protein is also important for stroke prevention. The protein content of 20% in regular laboratory diets was replaced with soy protein, which effectively prevented stroke. In contrast to short life-span in salt-loaded SHRSP (88 +/- 1 days), this life prolongation effect was intensified with the addition of 1.0% Ca (344 +/- 16) and became maximal with the further addition of 0.6% Mg (greater than 416 +/- 20).(ABSTRACT TRUNCATED AT 250 WORDS)