Read the following article and select the best answer. Article: Ever feel like you've been hit on the head after a bad night's sleep? According to scientists, the thought isn't as unbelievable as it seems. A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head. The researchers said the healthy young men examined in the study showed a sudden increase in the same chemicals which indicate brain damage. Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion . He said, "What we found was their levels in the blood rose in the group that went without sleep for a night. This was not to the extent that would happen after a head injury, for instance, but it was still significant. During sleep, the brain cleans poisonous substances off itself." Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis could applaud his study. The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue, he explained. Benedict, whose study is published in the journalSleep, added, "In conclusion, the findings of our experiment indicate a good night's sleep may be critical to maintaining brain health." A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago. Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours' sleep a night can lower the IQ the next day. Question: What do we know about previous studies? - They found reasons for brain disorders. - Their findings were published inSleep. - They were supported by Benedict's study. - They focused on brain health.
A:
They were supported by Benedict's study.