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I paid for the SAE paper on using the radioactive tracer on cam lobes and read it (2003-01-3119). They basically found that there was a scavenging effect on the anti wear film of the previous oil when a fresh oil is introduced. I'd quote the paper but that would be copyright infringement. But they definitely concluded that used oil produced lower wear rates then fresh oil on a broken in surface and even on a new surface.
I've seen evidence in too many places that show that changing your oil more often than is needed will cause more wear. Note I say more often then needed. So people who are changing oil every 3K when they have an OLM that says they only need to change it every 10K or 15K think they are "better than the engineers" are causing needless wear on their engine and wasting money.
Now whether the "extra" wear from changing you oil more often then necessary will actually result in premature engine failure remains to be seen. But it seems senseless to me to ignore the OLM or manufacturers guidelines because Jiffy Lube, your Dad, or some mechanic tells you to.