knee problem, grapefruit, & beta blocker family members brought a big bag of grapefruit from Texas. I was on a beta blocker for my heart condition. I soon realized that I could not eat grapefruit and walk. My knees became so weak I had to walk with a cane. From: verle Kins - Verlekins@cableone.net Story Categories UPDATED STORIES CATEGORIES   Jan. 01 2 Abdominal Aortic Aneurysm 0 Angina Oct. 08 1 Arrhythmia 0 Atherosclerosis 0 Cardiomyopathy 0 Congestive Heart Failure Feb. 06 3 Coronary Artery Disease 0 Defibrillators 0 Family History May. 01 3 Heart Attack 0 Heart Disease 0 Heart Murmur 0 Heart Valve Disease 0 High Blood Pressure 0 Obesity, Smoking and Lifestyle Oct. 15 2 Other heart-related topics Nov. 20 2 Pacemakers Aug. 01 1 Sudden Cardiac Death