You Could Use More Sleep - Here's Proof
Well, proof of sorts. Evidence more accurately. “What they discovered is that when the volunteers cut back from seven-and-a-half to six-and-a-half hours’ sleep a night, genes that are associated with processes like inflammation, immune response and response to stress became more active. The team also saw increases in the activity of genes associated with diabetes and risk of cancer. The reverse happened when the volunteers added an hour of sleep.”
See the whole article here: BBC Magazine.
It is likely to be more complicated than this, and we are all different, but it seems to make sense that having not enough good sleep has long term health impacts.