Please try not to be worried too much. You mention that he sometimes forgets current events, and that is probably normal for most people.
Sometimes is much different than all the time -- where people with dementia are, as they have trouble with their cognition all of the time.
At 53, it would be very unusual to have any significant dementia. But certainly, seeing a neurologist for evaluation is helpful, as they will do bloodwork, review the imaging studies, and do a neurologic exam to see if there are potential medical issues (this is called a "dementia workup") which cna cause memory issues.
Does early demential, if diagnosed, lead to possible disability compensation?