Yes, and more... Avacados deliver five types of nutrients (phytosterols, carotenoids, antioxidants, omega-3 fatty acids, polyhydroxylated fatty alcohols) that block inflammation, improve wound healing, and help fight: 1) heart & vascular disease; 2) cancers (prostate, skin, mouth); 3) metabolic problems (blood sugar & cholesterol control); 4) arthritis; 5) gingivitis; 6) skin disorders (scleroderma, psoriasis)
Impossible. I think that avocados are one of the healthier fats in a potential diet. But, there are several different cholesterol situations or problems and this question does not inform us in any way the cholesterol condition you have. Also one food in a potential list of hundreds of food items cannot be commented on as the solution to lowering your cholesterol in general.