My cholesterol is 227, how much should I worry?

Depends. Depends on whether you have other risk factors like smoking, diabetes, HTN or family history of premature heart attacks. Also depends on what your LDL and HDL are? 227 isn't very elevated but you're entering the coronary prone age and are wise to be thinking about it. Regular exercise, normal weight, not smoking and a vegetarian or mediterranean diet will do a lot of good!