If i become a vegetarian will that lower my cholesterol and increase my chances of not having heart disease like my mom and grandmom?

Yes but: Exercise & maintaining a lean body mass is also important ...Strong family history increases your chances by 2-3 fold...Good luck.

YES!!!: Vegetarians do have lower cholesterol & a much lower risk of heart disease, though the lower risk is not necessarily due to lower cholesterol! the real cause of heart disease is inflammation & a vegetarian diet is less inflammatory. There are many other health benefits to a vegetarian diet as well. See http://www.Vegetariantimes.Com/article/why-go-veg-learn-about-becoming-a-vegetarian/.