Sure. Turning the engine is going to take energy one way or the other. But you can use energy that would otherwise be wasted heating up the brake pads rather than energy from burning fuel.

I think the alternative was coasting, not braking.

So if you're coasting you're spending fuel to increase your speed (relative to what you'd do by staying in gear). In the situation where you're considering coasting that's probably not a tradeoff you want to be making.