From CaliforniaProtons

Foods to Avoid During Proton Radiation for Prostate Cancer
Key foods and ingredients to limit or avoid:
• High-fiber foods: Whole grains, nuts, seeds, and raw vegetables can worsen diarrhea and gas, which are common side effects during radiation.
• Fatty and fried foods: Fried foods, fast food, processed meats (sausages, bacon, hot dogs, salami), and high-fat dairy (ice cream, whole milk, cream) may increase digestive upset and inflammation.
• Spicy foods: These can irritate the digestive tract, especially if you already have gastrointestinal symptoms.
• Highly processed foods and sugars: Minimize refined sugars, pastries, and foods with hydrogenated oils, as they can increase inflammation and are generally less nutritious.
• Gas-producing foods: Beans, cruciferous vegetables (broccoli, cabbage), and excess simple carbohydrates can cause gas and bloating, which may interfere with treatment accuracy.
• Caffeinated drinks: These can worsen dehydration and digestive symptoms.
• Unpasteurized or raw foods: To reduce infection risk, avoid raw fish, unpasteurized cheeses, and undercooked eggs.
• Excess alcohol and salt: Both can worsen side effects and overall health during treatment.