Question

Colas and coffee contain a harmful substance called

Answer 1

Soda , I think it must be

Answer 2

A harmful substance present in colas and coffee is Caffeine.

Caffeine is a naturally found ingredient in coffee; it acts as a stimulant in coffee and drinks. Besides, it also adds flavors. Caffeine has a bitter taste and counters the sweet taste of colas and maintains a sweet-bitter taste.  

Caffeine is present in frizzy drinks, coffee, chocolate and other beverages.