Well, talk about a broad statement to ask an even broader question on...
To give a concise answer to this question would be next to impossible, as their are many variables that come into play in which an engine lubricant can have a negative effect on the internal combustion engine that it's lubricating: fuel dilution, wear particulate levels, active additive levels, visocity level, ect. All of those being in the wrong proportions can cause the oil to be more harmful than good, but those are only a slight few of the many that effect the oil and it's abilities/properties/effects.
Maybe trying to get your hands on a lubrication publication from Noria might help, but other than doing a full fledged publication yourself with references, their is no short answer to your question.
Sorry if that's not the answer your looking for, but I hope it helped steer you into a good direction for your continued research.