The phrase "acts as protection" is correct and can be used in written English.
You can use it when describing something that serves as a form of defense or safeguarding. Example: The thick layer of snow on the ground acts as protection for the plants and animals living underneath by insulating them from the harsh winter temperatures.
The Exchange acts as protection to buyer and seller alike; sees to it that all sales are consummated; government inspected, etc.
This 'two step authentication' acts as protection against criminals who have obtained our banking details.
In fact in The Sunday New York Daily News of December 5, 2010, a reader left a comment, "Tenure acts as protection against insecure administrators and financial crises but that is all".
Where urban areas are situated close to a beach, sand dunes act as protection from flooding and erosion.
Such groups were sometimes forged into semi-formal paramilitary forces, to act as protection and added muscle.
Moreover, the Sendai Tobu Highway played an important role in determining the inundation limit line, which in turn suggests that the highway partly acted as protection against the tsunami inundation (Sugawara et al., 2012).
Pat told us the video was inspired "by the theatre superstition that red roses act as protection against bad spirits, negative energy and injury".
Carapace fortification is thought to act as protection against invertebrate predation, e.g. by increasing the escape efficiency of prey when being caught by the predator [ 20].
This pathway has also been proposed by Abbott & Freeth [ 14], who argue that trust may act as protection against stress and anxiety by reducing apprehension about other people's behaviour.
By contrast, the determinants that were found to act as protection factors against this phenomenon were increased age and employment of the active-focused on the problem coping strategies of problem solving and cognitive restructuring.
This will act as protection against crushing the sandwich into a soggy mess.
