Bacon

Bacon is pork belly cured with salt and sodium nitrite (or nitrate), often smoked. The curing both preserves the meat and produces the pink color and characteristic flavor — but the same chemistry that makes it shelf-stable is what raises health concerns.

Processed meat and cancer risk

In 2015 the WHO's International Agency for Research on Cancer classified processed meats (bacon, sausage, ham, hot dogs) as Group 1 — meaning there is sufficient evidence they cause colorectal cancer in humans. The estimated risk is small per serving (~18% increased relative risk per 50g daily) but real and dose-dependent. Nitrites can form N-nitroso compounds in the gut, which are the suspected mechanism.

Migraine, reflux, and sodium

Aged and cured meats are high in tyramine and histamine — both common migraine triggers. The fat content slows gastric emptying, which makes bacon a frequent reflux trigger when eaten in the evening. A single 4-strip serving can also deliver 30-40% of a day's sodium, which matters for blood pressure.

None of this means a slice of bacon at brunch is dangerous; the evidence is about regular high intake. Treating bacon as an occasional flavoring (a strip crumbled over a salad) rather than a daily breakfast staple keeps the impact small.