Are Subway Black Olives High in Histamine?

Subway Black Olives

High histamine

Subway's black olives are brined olives, which are high in histamine.

Food here is usually assembled to order from components that were prepped earlier in the day, so it tends to be fresher than a drive-through and less fresh than cooking at home. Histamine builds up as protein foods sit, so how long the chicken or beef has been in the warmer matters as much as what is in the bowl. Treat the rating above as a starting point.

This topping is black olives held in water, salt, and ferrous gluconate.

Black olives — olives are cured and brined before packing, and that preserving process is what makes them high on the histamine scale.
A single preserved ingredient — there is nothing else driving this, so the olives themselves are the whole reason it runs high.

Leaving the olives off keeps your sandwich lower without much effort.

This rating comes from Subway's own published ingredient statement, read on August 10, 2026. Restaurant recipes vary by location and change over time, so always check the current listing: source 1, source 2. How we rate foods →

Subway Black Olives and Subway are trademarks of their respective owners. This page is an independent histamine reference and is not affiliated with, endorsed by, or sponsored by the brand.