“People love their coffee,” Dr. Gioffre says. But caffeine is an adrenal and liver suppressor, he adds. It is also very acidic. That’s why coffee can aggravate heartburn or cause acid reflux. Studies have shown that coffee oils may decrease bile acids and neutral sterols, which may lead to increased cholesterol. Too much caffeine can lead to arrhythmia and chest pain. Research by the European Food Safety Authority has linked caffeine overdose to panic attacks.