If you replace meat, butter and other saturated fats with nuts, all should lower your LDL cholesterol (commonly known as "bad" cholesterol). However, only nuts which have at least twice as much polyunsaturated fat as saturated fat will lower your LDL IF you eat them instead of carbohydrates such as bread and pasta.

If you look at the table* above, you will notice that walnuts, pistachios, almonds, pecans, hazelnuts, peanuts, soy nuts, sunflower seeds and pumpkin seeds have at least twice the polyunsaturated fat as saturated fat; macadamias, cashews and Brazil nuts do not and will not lower your LDS when eaten in place of carbs.

*Source: U.S. Department of Agriculture Nutrient Database