Atherosclerotic cholesterol ester deposition is markedly reduced with a high-potassium diet

In a normal rat on a normal diet, no cholesterol esters are detected in the aorta by gas chromatography. Stroke-prone spontaneously hypertensive rats (SHR) were fed for 3 months a basic diet containing 4% cholesterol, 14% coconut oil and 7% NaCl. One group of 13 rats ingested a normal (0.5%) level of potassium in the diet. Another group of 10 rats ingested a high (2.1%) potassium level. Mean intra-arterial blood pressures averaged 165 mmHg in the normal-potassium group and 161 mmHg in the high-potassium group (NS). Serum cholesterol levels averaged 229 mg/dl in the normal-potassium group and 214 mg/dl in the high-potassium group (NS). Total aortic cholesterol esters per rat involving 16- and 18-carbon chain fatty acids averaged 187 micrograms in normal-potassium rats versus 68 micrograms in high-potassium rats. These were the main esters; other esters were negligible. Thus, the high-potassium diet reduced cholesterol ester deposits by 64% (P less than 0.0003), even though blood pressures and cholesterol levels were quite similar in the two groups. Both high cholesterol and high blood pressure injure endothelial cells and increase the invasion of macrophages and vascular smooth muscle cells into the intima; they also increase endothelial permeability to proteins. With high plasma cholesterol levels, these processes lead to atherosclerosis with cholesterol ester deposition. The high-potassium diet, by protecting endothelial cells, can greatly decrease this cholesterol ester deposition. This effect could be useful for preventing heart attacks and sudden coronary death in human hypertension.