That’s complicated. The germs on your hands aren’t the same germs that cause breakouts, but the dirt and oil you touch may be a problem. “Think about all the things we touch in a day without thinking about it — food, hair, doorknobs, pets,” says Papri Sarkar , MD, a dermatologist in Boston. “You’re always transferring something onto your face.”“Oil-based, or thick, greasy products can clog pores,” Dr. Sarkar says. “With the sealed-off pore and extra oil, the bacteria that cause breakouts have plenty of food and can multiply with abandon.” She says pulling your hair away from your face when you sleep and choosing oil-free, silicone-free products can help prevent more breakouts. And, of course, you still shouldn’t touch your face. Anytime you disturb oil glands and hair follicles, you risk irritation and inflammation.Another common question about acne causes is whether what you eat worsens your breakouts. That depends. If you regularly polish off pints of gelato, then probably. “One of the strongest links between what we eat and acne is glycemic index ,” says Whitney Bowe , MD, a dermatologist in Briarcliff Manor, New York. “Low-glycemic foods seem to have a beneficial effect on acne, while high-glycemic foods — carbs and sugars — cause a spike in blood sugar that leads to acne flares.”Some research also suggests that dairy products, especially skim milk, may play a role in breakouts. Dr. Bowe says studies indicate that the high levels of whey protein and casein stimulate acne-causing hormones. The one exception to the dairy rule: yogurt, says Dr. Bowe. “Probiotics seem to have a role in controlling breakouts, so yogurt is great, as long as it’s low-sugar.” Eating healthy fats can also calm breakouts. Omega-3 fatty acids have anti-inflammatory benefits that can help with the chain reaction that causes inflammation, she says.