1) Diabetes and obesity: a lack of sleep can be the cause
During a study in the University of Chicago, the researchers noticed that sleep problems can potentially cause obesity, which in turn can lead to diabetes. Because the level of fatty acids in our blood can have an impact on our metabolism and the ability of insulin to regulate our blood sugar levels, the researchers analysed the effects of sleep deprivation on the accumulation of fatty acids.
By comparing 19 men and their sleep patterns, the researchers determined that those who slept for only 4 hours a night for three days had higher levels of fatty acids in their blood, which was 30% higher than those who had slept for 8.5 hours each night during the same period. Furthermore, in those who had less sleep, the increase in fatty acids caused an increased resistance to insulin. Both of these are signs of pre-diabetes. Those who slept more did not present with the same signs of obesity or pre-diabetes.
2) Lack of sleep could cause Alzheimer’s disease
In 2013, researchers in John Hopkins University in the US led a study that concluded that sleep deprivation can be one of the causes of Alzheimer’s disease and can increase its rate of progression. The research was based on a previous study which showed that sleep is indispensable for the brain in terms of helping it get rid of “cerebral waste”, an accumulation of toxins that can cause dementia.
The study was carried out on 70 adults aged from 53 to 91 years of age. The researchers showed that those who reported having slept badly had higher quantities of beta-amyloid deposits in their brains, an irrefutable marker of Alzheimer’s disease. The researchers therefore concluded that sleep deprivation prevents the brain from getting rid of “cerebral waste” and can lead to Alzheimer’s disease.
3) Higher risk of developing heart disease
According to a study presented at EuroHeartCare, the annual meeting of the European Society of Cardiology, there is a strong correlation between sleep deprivation and heart diseases. Having followed 657 Russian men from 25 to 64 years old over a period of 14 years, the researchers determined that almost two thirds of those who had experienced heart problems had also presented with sleep difficulties.
They also found that the men presenting with sleep difficulties were at 2.6 times higher risk of a myocardial infarction, a heart attack caused by the failure of the heart muscle. They were also between 1.5 and 4 times more susceptible to stroke.
4) Sleep deprivation and suicide
In 2014, researchers completed a 10 year long study and found a link between sleep difficulties and increased suicide rates in adults, independent of a history of depression. Of the 420 adult participants examined by the researchers in the University of Medicine in Stanford, US, 20 participants suffering from sleep difficulties unfortunately took their own lives. The researchers therefore concluded that those who had frequent sleep problems were 1.4 times more susceptible to suicide, but that white men aged 85 or older were the most sensitive to sleep deprivation. The study finally attributed these increased risk levels to lack of sleep associated with health problems and stress, which increase with age.
5) Higher risk of developing prostate cancer
According to a study in 2013 published in Cancer Epidemology, Biomarkers and Prevention, the researchers noted an increase in the risk and degree of prostate cancer in patients presenting with sleep difficulties. They followed 2,523 Icelandic men from 67 to 96 years of age over a period of 3 to 7 years, and found that the risk of developing prostate cancer was 60% higher in men that found it difficult to sleep.
The researchers concluded that raised levels of melatonin in our bodies, the hormone that regulates sleep, can reduce the growth of tumours. The tumours grew more aggressively in men who were exposed to high levels of artificial light, which is a known cause of sleep problems.
6) Sleep deprivation: a cause of ulcerative colitis
Ulcerative colitis is an inflammatory illness of the intestines, characterised by the presence of one or more ulcers on the walls of the intestine. According to a study carried out by researchers in the General Hospital in Massachussetts in 2014, this can be caused either by a lack of sleep or by excessive sleep, as well as Crohn’s disease. The researchers found that good quality sleep halted the inflammation of the digestive system, which is often the cause of such illnesses.
The risks of ulcerative colitis are increased if sleep duration is less than six hours or more than nine hours a night, independent of factors such as age, weight, smoking and drinking.
What is the ideal amount of sleep?
The ideal amount of sleep is between a minimum of six and half hours and a maximum of nine hours per night.