How Much Sleep Is Healthy? Study Finds That Lack of Sleep Can Lead to Cancer, Dementia
A new paper suggested that lack of sleep increases the risk of lung cancer and dementia. Experts at the University of Eastern Finland made a 20-year follow-up trial on the Kuopio Ischaemic Heart Disease Study conducted from 1984 to 1989. At that time, 2,682 men aged 42–60 years took part in the study.
The research associated lack of sleep with low levels of inflammation and disruptions to the secretion of the "sleep hormone" called melatonin. This, in turn, leads to tumor growth in the lungs that causes cancer. They also found a link between reduced sleep duration and high copper levels in the blood which increases cancer risk.
Disturbed sleep further raises the risk of dementia by 1.5 times as it disrupts the person's hormones. During this stage, a protein known as amyloid-beta accumulates, which reduces the volume of the part of the brain associated with memory. This triggers inflammation and prevents brain cell renewal.
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The study recommends seven to 7.5 hours of sleep. Oversleeping is discouraged as increased mortality risk is also observed in individuals with long sleep duration. "Sleep duration deviant from the population mean, and sleep disturbances such as insomnia, circadian rhythm sleep disorders, and sleep-disordered breathing are the most widely investigated conditions regarding to adverse health outcomes," Maria Luojus, author of the study said.
The link between sleep disorder and mental illness is nothing new. Another study showed that missing sleep could increase the risk of dementia in the long run. Scientists from Marche Polytechnic University in Italy analyzed the brains of mice and the effect of sleep loss.
The research found that chronic sleep deprivation on mice triggers astrocyte cells to break down the brain's connections. Also found was excessive microglial activity, which has been linked to brain disorders. "We already know that sustained microglial activation has been observed in Alzheimer's and other forms of neuro-degeneration," Dr. Michele Bellesi said.
