No, there's no scientific study that directly links vegetarian or non-vegetarian food to erectile dysfunction. In fact, a diet such as the Mediterranean one that incorporates plenty of fruits and vegetables, including lean meats, is co-related with low incidence of erectile dysfunction. Ideally, red and processed meat should be reduced from your diet to minimise risks of erectile dysfunction. Also, if you're vegetarian, deficiency in Vitamin B12 may harm the spinal cord, which may affect the nerves relaying messages to the arteries in the penis. So get your B12 levels tested and take a supplement if necessary and prescribed by your doctor.