You can check this out for yourself. Search PubMed or Google Scholar for “sleep deprivation cancer risk.” Plenty of studies come up, but the vast majority find little-no link. The biggest hazard ratio I could find was 1.6, which is not a doubled cancer risk. Note also that Walker has actually retracted his “WHO has declared a sleep epidemic claim,” so we have a concrete example of the guy making stuff up.
You can check this out for yourself. Search PubMed or Google Scholar for “sleep deprivation cancer risk.” Plenty of studies come up, but the vast majority find little-no link. The biggest hazard ratio I could find was 1.6, which is not a doubled cancer risk. Note also that Walker has actually retracted his “WHO has declared a sleep epidemic claim,” so we have a concrete example of the guy making stuff up.