A new study has raised the extraordinary possibility that humans may be able to put themselves into a kind of hibernation state - but in a way that hurts us rather than helps us.
The research, published in the Proceedings of the National Academy of Sciences, focuses on the devastating condition known as myalgic encephalomyelitis, more popularly known as chronic fatigue syndrome.
CFS is one of the biggest mysteries of modern medicine and is characterised by severe fatigue and related issues such as headaches and memory problems. Millions suffer from it, but no cause has ever been pinpointed. That has made some doctors so sceptical of the diagnosis that many patients complain that they have sought help only to be told the symptoms are in their heads.
The study, led by University of California at San Diego researcher Robert K. Naviaux, looked at metabolites in the bodies of people with CFS and those without. Only 84 people participated, 45 with CFS symptoms and 39 who served as a control. Naviaux looked at 612 different metabolites, which are intermediate substances such as glucose produced by cells as they break down larger molecules and produce energy. The study found that 80 per cent of the metabolites were lower in those with CFS. It also found "abnormalities" in 20 of the metabolic pathways.
All this suggests that the metabolism of people with CFS is markedly slowed down.