Understanding sleep and health

World health day is celebrated on 7th April every year under the auspices of WHO (the worldwide watchdog of human health) to guarantee dignified and healthy life to every human being irrespective of age, gender, ethnicity, caste, region or religion.

This year’s theme is “universal health coverage: everyone, everywhere”. Despite the plenty of health care measures by WHO and health services of every country, the irony is that everyone who needs health care does not receive or get it. Further, millions of people particularly in African and Asian countries are yet to receive the basic health care facilities and food.

In this write-up I shall be dealing with the sleep and its everlasting effect on our health. Sleep is a physiological state of mind and body for reducing the interaction with the human surroundings as a means of natural adaptation to primarily suspend the voluntary bodily functions during sleep hours. Sleep deprivation is therefore, the root cause of so many human health issues and diseases.

The obstacles and factors to get an optimum sleep are many ranging from stress to diseases. During the last one or two decades use of smart phones and lap tops is considered big jolt to our health by pushing our sleep timing into late hours in the night due to habit of using these electronic gadgets on average one or two hours within the bedtime.

Another problem is keeping the smart phones near to our sleeping pillows throughout the night hours. These smart phones emit light falling in the blue spectrum and has been found to cause suppression of sleep hormones, thereby depriving us of precious sleep hours.

Sleep is a vital indicator of normal well-being and plays a housekeeping role to detoxify the human body and boost the development of immunity. Insomnia or sleeplessness is a root cause of many human diseases and sleep deprivation results into various behavioral, metabolic and physiological consequences. Good health is not possible without immunity and optimum immunity is not possible without adequate sleep.

The communication between the nervous and immune system are mediated by various signals (neurotransmitters, hormones and cytokines) and thus provide the basis for the primary influence of sleep on various immune processes.

Research has shown that people who get inadequate sleep also tended to have lower levels of immune cells particularly the natural killer cells-the important component of immunity against self-altered, virus infected and tumorous cells in human beings. Similarly, cytokines (regulators of immune system) influence the spontaneous and infection-associated sleep (sleep problems are common during various infections and diseases).

The internal body clock of our body called as circadian rhythm regulates the 24-hour cycle of biological processes including sleeping patterns such as when we sleep and when we wake.

How much sleep do we really need for a healthy life has always been on the frontline of research? An eight hour night sleep is considered to be an optimum requirement for the healthy life, however, the requirement varies as per the health condition and is more for the infants and children.

The circadian genes and clock genes are involved in the regulation and functioning of circadian rhythm in human body. There are various genetically associated sleep disorders and many mutated genes have been found which result in the fragmented and altered sleep in human body. Therefore, sleep patterns and behaviour vary across individuals due to genetic makeup as well as due to cultural and environmental factors.

Our immune system is strategically designed to protect us from day to day trauma and common diseases like colds and flu. Less or lack of sleep makes us more prone to catching colds and the flu because inflammatory cytokines increase under such physiological conditions driven by less sleep commonly known as ‘cytokine storm’(over-reaction of immune system). Research has shown that the best treatment to get rid of flue and influenza like symptoms in our body is adequate rest and sleep.

Adequate sleep keeps our immune systems always primed for attack and protection. Therefore, having a strong immune system is very important for dealing with flue and other related illness in human beings.

Ample research studies have shown that our T-cells (special type of immune cells responsible for cell-mediated immunity to deal with particulate and cell bound antigens) go down if we are sleep deprived. Sleep helps in the healing process, which is purely an immunological response of our body towards various types of trauma. Lack of adequate sleep results into its improper functioning or suppresses immune functioning.

There is also a strong link between sleep deprivation and cardiovascular diseases including diabetes and obesity. Recent research suggests that sleep-deprived people are at higher risk of dying from heart disease than people who get adequate sleep. Because more the sleep loss, higher are the levels of C-Reactive Proteins (CRP) in the body, responsible for elevating incidence of heart disease due to marked increase in inflammation.

There is a strong evidence that accumulation of various types of lymphocytes (special immune cells) in lymph nodes occurs during night sleep. Therefore, getting optimum night sleep helps in boosting the production and development of our immune cells. Further, research has also shown that a single night of normal sleep after vaccination strengthens the natural immune response against an invading antigen.

To conclude, the old slogan of “early to bed and early to rise” with an adequate sleep duration makes sense and going to sleep at the same time every day and waking up at the same time is, therefore, an indication of strong immunity and healthy life. Therefore, to discourage the late night bed time and late morning wake time is the key to a healthy life.

Dr. Khurshid Ahmad Tariq is Assistant Professor, Department of Zoology, Islamia College of Science & Commerce